joist boring -framing inspection failure
garch
| Posted in Construction Techniques on
I need to make a recommendation to an uniformed electrician/general contractor. It became apparent in the framing inspection that the electrician bored all of his holes 1-1/2″ from the bottom of the floor joists. We are under the IRC, so a min. of 2″ is required. What is the easiest/best “fix” for this situation? Should I be looking at a Simpson strap tie or stud shoe? Thanks for any suggestions!
Replies
Ask your framing inspector what 'fix' he'll accept
unfortunately, the town building inspector is unwilling to suggest anything and therefore leaves that decision up to me (that was my first response too)
Bottom line to make sure it must pass is getting an engineer out to evaluate the location of the holes in the span, species, spacing and grade of joists and determine what remedy will make the joists as strong as they were before the holes. Any other 'good guess' would be just that and subject to arguement.
Send the bill to the electrician, could maybe qualify as an education expense?
I assume we're talking about 2X floor joists? You really didn't mention.
I think you'll pretty much have to hire an engineer, if your building inspector won't help you out any.
Be sure to pass the cost along to the sub who drilled the holes...
I had a plumber's helper 'do the deed' about 3 months ago. I pointed it out and the plumber had his guy remove the pipe (supply water lines), put 1/2" plywood on each side of the effected joists, nail liberally on each side with 8 penny nails, rebore about 4" from the bottom, and reinstall pipes. The building inspector looked at it but did not say anything. Our BIs are as apt to fail you as not, so don't think we got it easy here.... Anyway, that's just my (recent) experience.
It's very simple. Ask your Architect for the solution and deduct from the electrician what it cost to fix it.
Right answerbuthow much you wanna bet that Garch stands for great architect
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*chuckle*
how much you wanna bet that Garch stands for great architect
Dunno, the ones that assume they are great rarely seem to think in such humble ways. If such deigned to chat among the plebes here, they'd have some grandiose handle like "Wryfthulwyr" or "Maestro" or "▬5■²√·∙≈▬" or some such.
"garch" could be as simple as "george" or "Archie G." or the like.
A prima donna would not be worried about such mudanery as mechanicals bored accurately, the finsh, the finsh, much more important!Occupational hazard of my occupation not being around (sorry Bubba)
never meant to suggest prima dona. I just thought it was fairly clear from the tenor and language of the post, coupled with the screen name that he was an architect.garch, sorry if you took it as a slam at all. I save my slams for those who earn them. I this inspector demands nembers, or an engineered fix, that's just your job. But how to handle the cost is probably the greater dilema you had. The electrician should eat it or at least split it wioth the contractor is he is otherwise good. That's my opinion.
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The electrician should eat it or at least split it wioth the contractor
I don't agree Piffin: Why should the GC eat any of it?
When I screw up, I pay and fix my screw ups. I don't ask the GC to eat half of it. This electrician needs a lesson. I'd guess he's too short to reach the middle third and too lazy to get a ladder. Now he'll have to pay the piper. I'd probably tell him that he has to make the repairs himself or be prepared for the financial shock of his life.
I don't have much patience for the mechanical trades who hack up the frames. In most cases, I don't have any control on how to "re-educate" them because I'm a sub, but if I was the GC, they'd learn real fast that if they hack something, they're going to find out how much pain it really causes!
blue
You didn't mention how critical the strength is. Did the inspection fail because the wires are simply too close to the edge to meet the exact letter of the code (fail on technicality) or because of the strength lost when the holes were drilled this close to the edge? I'm picturing a little 3/4" hole with a few strings of romex on a joist that is way stout and doesn't need anything structurally.
Perhaps there was a miscommunication with the inspector and he doesn't care what happens as long as the wires are simply moved?
Your post does have a strange sound to it.
Best of luck,
Don
Been there done that. Plywood gussets on each side of the joist gluded and screwed, full joist heighth, in our case 1/2" ply 4' total, 2' on each side of the hole. Calculation by a structural engineer, much better than an architect, for $350. Back charge the sparky.
Also make sure Mr. Sparky knows where to drill the new holes. Middle of the joist middle of the span is a good choice.
Middle of the span??? There's much less stress in a joist towards the ends than the middle.
Middle of the joist, at one of the end 1/3rds is what I use.
Edited 12/7/2005 3:06 am ET by kicker
Thanks for all of your help! I am the architect and I have not seen the situation yet, only heard about it. I know that as soon as I step on site, I will be asked for an immediate solution. I wanted all of your input of what is "reasonable" to ask for, since you are the experts out there... I hate being the architect that wants something that is unreasonable to fulfill.
I, too, am imagining small holes that do not affect the critical strength much, but, believe me, I will run the numbers if the damage is more than expected.
thanks for the input!
Edited 12/7/2005 9:16 am ET by garch
holes that do not affect the critical strength much
You and another poster are missing the point. There are locations on the joists where holes are not allowed, and the inspector has found just such a mistake on your job. It's like being pregnant: either the holes are in an allowed location, or they are not.
"When asked if you can do something, tell'em "Why certainly I can", then get busy and find a way to do it." T. Roosevelt
holes that do not affect the critical strength much
You and another poster are missing the point. There are locations on the joists where holes are not allowed, and the inspector has found just such a mistake on your job. It's like being pregnant: either the holes are in an allowed location, or they are not.
I'm not sure you've understood what the original comment was about. The conversation was not if the wires would need to be moved, but rather what structural damage has occured. Yes, there are locations where holes are not allowed, unless they are within the limits of a notch, in which case a hole isn't considered a hole. Even if a hole is in the wrong place, it's not always necessary to complete any structrual repairs on the joist.
A small hole reduces the joist's strength no more than a knot of that size. If it takes an engineer's stamp for the inspector so be it. Along those same lines, if the joist is determined to be structurally sound with the holes then the wires shouldn't have to be moved.
On a 2x10 the outer 1/3 can be notched 1/6 the depth of the joist (IRC), or 1-1/2". I'd pitch a bitchh if the electrician's holes were simply on the outer 1/3 of the joist and thus acceptable under the code as notching.
Cheers,
Don
R502.8.1 Sawn Lumber - .... The diameter of holes bored or cut into members shall not exceed 1/3 the depth of the member. Holes shall not be closer than 2 inches to the top or bottom of the member, or to any other hole located in the member. Where the member is also notched, the hole shall not be closer than 2 inches to the notch.
Holes are not restricted to any area of the joist, rafter or beam except as quoted above. Notches are limited to the outer 1/3 - not allowed in the center.
As long as you are quoting code, please tell us what code/revision it is. Different states/providences use different model/revision codes.
That said, it appears you are quoting IRC. We use IRC2000 modified for NC which says that you are not allowed to notch or bore the center of the length of the joist although ours says in the center 1/5th. We used to use a modified CABO, which also said the center of the span was off limits.
Personally I think the guys who are saying the center of the length is the best place to drill holes are mistaken.
Quote was from 2000 IRC
Code is code I am sure. The issue could be nothing more than to protect the wire from deep nails. Maybe there is no structurally issue at all. It could be to protect teh wires or the inspector could just be saying "the code is the code".
It is odd that the inspector will not tell anyone what the issue is?
Don't get me wrong, I have no experience in this area, but was just thinking about the issue of protecting the wires.
I wanted all of your input of what is "reasonable" to ask for, since you are the experts out there... I hate being the architect that wants something that is unreasonable to fulfill.
Great and successful attitude!
I started framing in 1971, and continue today as a custom builder. Over the years I have weeded out the architects and engineers who do not want my input and insist on their own calcs, methods and configurations, even though they may be unfriendly to builders / subs.
I consider an architect or engineer very wise when I take them a design problem and they ask "What would you do?" The architects and engineers who work for me appreciate and use most of my input.
Sometimes I design a frame or concrete situation, do the drawings on Softplan and submit the drawings to them. They check the work, revise as necessary and sign off. I save their time and my money, get the situation solved quicker and we are all happy.
I designed a stiffback / roof brace configuration for large clear spans that neither they nor I had ever seen before. My engineer now uses the configuration as a regular part of his detail page when the situation dictates, and the input from a new framer I am using "Man, I have not seen that before, it is stout as hell".
> I designed a stiffback / roof brace configuration for large clear spans that neither they nor I had ever seen before. My engineer now uses the configuration as a regular part of his detail page when the situation dictates, and the input from a new framer I am using "Man, I have not seen that before, it is stout as hell".
OK, so drop the other shoe here. Give us a drawing and description of this detail.
-- J.S.
Hey, I wouild love to share, but then you guys would tear me to pieces and I would drift back into depression and start drinking. I would not surface for two to three years.
Just kiddin...I am trying to figure it out......see my post to Piffin.
OK, give it up! We all want the best...
Welcome to the Taunton University of Knowledge FHB Campus at Breaktime. where ... Excellence is its own reward!
I assume you are talking about the stiffback / roof brace detail?
I have it in my SP drawings, but my attach button does not seem to be working in BT. I have made sevaral attempts to post a pic with a long haired street dude sitting on plastic milk crate holding a sign that says "Need cash for alchohol research."
Also, if I find it working next time, how do I post the drawing? What size does it need to be? You know the dxf / SP files can be large.
Hey, if the detail is what you are talking about I'll be glad to print and fax. Maybe then you (or someone) could scan, create electronic file and post it.
Edited 12/8/2005 6:24 pm ET by txlandlord
The strongback is what I meant.You can email to me at
[email protected]
or fax at 207-734-6993 when I am offlinebut you really need to be able to post pictures here.So first, open it in SP, and save as a jpg or btmp file or even print to PDF, and post that file here.To post, you reply and with the reply, you hit the 'attach files' button. When it opens a new dialouge window, use the browse button to fgind the saved file on your pc. once you select it, hit the 'Upload' button and go get a cup of coffee.
That is the critical thing most folks miss. You have to WAIT long enough for Prospero to acknowledge that they have the file or photo. Sometimes it is quick and sopmetimes it is like waiting in line at the DMV...But once they have it, the window will show the name of the file you just loaded up, right about in the center of the window. If you have more than one to do, now is the time to browse and grab another one. if not, hit the 'done' button, and then post the reply. usually while i am waiting for acknowledgement is when I type the text in the reply box.Good luck.
Welcome to the Taunton University of Knowledge FHB Campus at Breaktime. where ... Excellence is its own reward!
When I hit the Attach Files button, nothing happens, no dialog box as when I attach to an email. I reported this as new post "Problem". Someone said to disable my windows pop-up protection and my security software pop-up protection. I did this without results. Bummer.
How hard is it for these a-hole electricians and plumbers who do things like this to drill the holes in the right spot?????From now on the Architects should just have a little drawing on all the plans where you can drill a hole in a 2x joist in the plumbing section and the electrical section just like the pamphlets have for I-joists.I'm a framer so I could care less where a hole can and can't be drilled because I don't drill holes in framing. So you think that since the a-hole plumbers and electricians who are the ones that drill holes and ruin joists who DRILL HOLES IN WOOD EVERY DAY for a living should know where they can and can't drill a hole.There’s guys want to hack up the framing on one of my jobs, they will pay for me to come back and fix it. There's no excuse for this unless there was a young kid who did it and then the boss came back and found it and called the GC and let him know what happened and will pay for it. That's a different story. I've seen experienced electricians and plumbers who are the bosses do stuff like this, so there is no excuse at all.They should make a sticker up that shows the minimum height from the bottom of a joist to the hole in RED and pass it out to all these guys and have them stick it right on their drills.Joe Carola
I can't argue with you about the 'trade' folks being a but liberal with their cutting and drilling at times. I do think that most problems can be avoided if the plans have been well put together and the placement of plumbing fixtures is considered when the framing layout is drawn up. Too many lazy designers just put down what joist spacing is reqiured for the type of joist and ignore the fact that drains need to fit. There are also times when a plumber or electrician just isn't thinking. These ARE things the GC should have looked at in advance and made sure everyone understands what goes where. There will always be screw-ups but good planning before hand can keep them to a minimum.
This has been an interesting thread for me.
"There are also times when a plumber or electrician just isn't thinking. These ARE things the GC should have looked at in advance and made sure everyone understands what goes where. There will always be screw-ups but good planning before hand can keep them to a minimum."Yes, there are screw ups but even if that does happen, it still has NOTHING to do with the electrician or plumber drilling the holes 1-1/2" up from the bottom of a joist. That is no one else’s fault but the guy who drills the holes there.An electrician and plumber should know where NOT to drill a hole in a joist just like me as a framer has to learn where to center of a toilet or bath drain is so I don't put my joists in the way. It's that simple. A bathroom layout is on the plan with the toilet and shower there with measurements for the width of the walls where a toilet will sit in between the two walls. So that tells me my center and now I will come off the back of the toilet wall 13" to the center of the waste line and MAKE SURE there's no beam in the way. It's that simple. If there are no measurements for the toilet locations I will call the GC up and tell him to come down here and we'll lay it out together. I won’t just put my beams in. if I'm not sure of something, I will call the GC or plumber and tell them to come here and we'll go over that also.Yes, things get screwed up all the time but in my case as long as the layout of the toilets and tubs aren't changed from the plans and I follow that I'm ok. If there are changes later and a joist is in the way and has to be moved, I will move it but it will be an extra.
Joe Carola
My favorite quote, when an engineer told me I'd have to repair joists butchered by (previous generation) plumber, my current plumber says: "Oh that's just numbers."
Joe, I agree, the guys drilling and cutting should know their limits and do the right thing.
If a fixture has to go in and there is a structural member in the way, the plumber should simply call the jobsite superintendent and ask for direction. Instead, he hacks it up. Sometimes it would only take us 1/2 hour to remove all the fasteners on the joist and move it. If it gets hacked, it might have to be replaced. If there is wire and ductwork it might take four hours plus the removal and replacement of the the ducts. It might take a week to get a joist made if it's manufactured.
Sometimes the fixture placement is a result of a change of plans and it wasn't possible to know beforehand where that drain was, so it's not always someone "fault".
I don't have any respect for hackers who hack up the structural components. I hope a beam drops on their head.
blue
These a-holes crack me up when they do sh!t like that. It takes two seconds to make a phone call so everyone can get together and figure it out. And if one of the trades doesn't want to take the time to figure it they they should get thrown off the job.Joe Carola
Amen. Unfortunately it usually will be up to the subcontractors, GC, in conjunction with especially the framing contractor to get things laid out correctly. Also, unfortunately as has been discussed many times, architects don't server on site internships which would also be helpful. Also equipment, accessories, fixtures, and materials change from those contemplated or were never spec'd.
On my jobs we have a job meeting to rectify these exact potential problems before they become problems. Also if decisions haven't been made or can't be made the ramifications, extras, change orders, delays, etc, can be communicated to the architect and owner.
As you've indicated a good experience framer is usually ahead of everyone else on these potential pitfalls.
Never serious, but always right.
You think the archi should do a drawing for this? Why? Do you expect a car designer to tell a mechanic how to do every job? What's more important- whether the building stands or where the drains are located? It's pretty common knowledge that the middle third is where holes are to be drilled/bored. It's up to the trades to keep up on their code requirements. The lumber producers could put a line on all floor joists at 1/3 in from both edges, but they don't. It would cost money for this. Same with the archis, but they could just use a boilerplate document. You, as a framer, don't need to care where they drill holes. For the rest of you, when was the last time a sparky cleaned up after himself? I don't mean "kind of" sweeping it all into a pile, either.
"I cut this piece four times and it's still too short."
"You think the archi should do a drawing for this? Why? Do you expect a car designer to tell a mechanic how to do every job?" That makes no sense at all what you just said.Yes, an Architect should make a drawing like that for something like this because IT'S STRUCTURAL drilling holes threw beams in the wrong spot."It's pretty common knowledge that the middle third is where holes are to be drilled/bored."How's that common knowledge? How are any trades supposed to know where to cut a beam? Where is it written? So it's common knowledge for an electrician/plumber to know this, how? When they take there test, is it in there? If it is, then these guys are even bigger a-holes than I thought.I';ve never heard about the middle third before and I've been framing for 22 years. The only thing I ever heard was that no beams can be drilled less than 2" from the bottom and up.If the electricians and plumbers learn where and where not to drills holes when take their test, than that's where they learned it. If not, it's up to them to ask so they don't cut these beams in the wrong spot. If not and this crap keeps happening all the time then the architects should make a note because it is STRUCTURAL and electricians and plumbers are drilling holes in beams every day. So wouldn't YOU think that it is important? And again to be fair to the electricians and plumbers, how are they supposed to know what's Structural in a beam unless they were taught that.Joe Carola
What I meant was, many architects (I couldn't give a % because it would be hard to find out) design for function and cosmetics without doing the structural analysis and design. In medium and larger firms, archis design the look and function, along with the interior designers, the mechanical engineers do their thing, the structural people do theirs, electrical do theirs, etc. There definitely are architects who can do it all, but they usually have P.E. after their name and many are snapped up by larger firms. The car reference was basically, should an auto designer need to tell the people who build and repair cars how to do their job every time? I don't think so. Sorry for the weird analogy.In my experience, it has been common knowledge- I have been doing low voltage wiring for a long time. I just took the CEDIA test (Custom Electronics Design Industry Assoc) and it was on the basic test. This test was very basic and I hope the electricians teach at least this much. I think every home theater installer I know is aware that you don't just drill wherever they want. It's actually pretty easy to get the technical specs for a particular beam, truss or joist. The manufacturer or ASTM has all of this and either a phone call, e-mail or going to the lumber yard/distributor is all it takes.You say they hack joists up all the time and I'm wondering why you need to be fair to them. I have to think they have been tuned up for drilling in the wrong place at least once or overheard someone else getting an earfull. Also, people talk on the jobsite and unless they don't listen, don't care or can't hear what's being said, the electricians and plumbers may just think that it's ok, there's another joist nearby. I don't know if they know this or not, but if they aren't being taught, the big question is WHY NOT???? As you said, it's structural and very important. I agree with you. I don't know why you hadn't heard about it, but could it be that you aren't always there when the plumbers and sparkies are? Also, there are archis who spend very little time at jobsites. That's why the builder has expeditors and job supers. Personally, I think anyone who would ever have a need to drill into a framing member should know this stuff. You know as well as I that some people will just not ask questions, even though the answers are necessary for them to do tehir job right. I think we agree that it's very important, but it's also amazing that apparently, not much is being done about the problems.
"I cut this piece four times and it's still too short."
If you pay an architect for a set of plans, they ought to have all the structural details worked out or the plan is not complete! How can you put a plan out for bidding if all the information you need to build the building is not on the plans. Having said that, It is not his job to specify where you can drill holes in joists any more than it is his job to specify a nailing schedule for built up LVL beams. This info. is supplied by the manufacturer. Likewise, a mechanical contractor ought to know where he can drill holes in joists because driling through them is part of his job. Every plumber and electrician ahould have a copy of the code regarding this. If the joists are engineered, the contractor should have the literature from the manufacturer on site. Every supplier has this stuff from the manufacturer.I've had situations where the plumber has come to me to say there is no way do his job without drilling a hole in a prohibited location. If it's conventional lumber I usually nail and glue (with construction adhesive) a 4' piece of plywood on each side of the joist he's going to drill first, keeping my nails out of his hole location. If it's engineered lumber it usually takes a call to their local rep. You'd be surprised at the size of the holes you can drill if you give them a little more info. on how your beams or joists are loaded.
>>"It's pretty common knowledge that the middle third is where holes are to be drilled/bored."
How's that common knowledge? How are any trades supposed to know where to cut a beam? Where is it written? <<
Sorry bud, not meaning to be rude but read my 66760.59 post above. Granted this drilling/notching thing may not be the type of thing a framer needs to know on an everyday basis, but there are probably at least 3 or 4 chapters in whatever code your state uses that you should be quite familiar with and I'll bet drilling/notching is covered in one of them - probably a chapter called "Floors".
And yes, the drilling/notching thing is common knowledge with my plumbers, electricians and HVAC guys. Probably have an issue one house in 20; there is always gonna be one DA. The DA plumber example I gave early on in this thread was the boss's son - a college boy on summer break who no more intends to be a plumber than I intend to be a fashion designer...
For anyone who is still having a problem with this joist drilling thing, talke a look at this link (a pdf documnet) and look at the picture and notes below on page 5: http://www.johnstonnc.com/files/inspections/spanchart.pdf
Do not drill in center 1/3 of joist span.OK, now my teensy weensy brain is confused. That line above is copied from page five of the Span Chart you provided. So, can you or can't you drill in the centre third? I thought some of the pros thought it was OK. Now, unless I'm missing something it's pretty easy to see how mistakes are made by a mere rookie in the biz.
Woodroe said, " The largest holes permitted in joists are always in the middle third of the joist width and in the center third of the joist length. There is more stress on the outside thirds of a joist than the center third."
I'll sleep better tonight if someone can answer this succinctly. Thanks to all.
Ken"They don't build 'em like they used to" And as my Dad always added... "Thank God!"
"Do not drill in center 1/3 of joist span." That link says the same as my calcs and basic model (which is just theory), drilling in the middle 1/3rd of a floor joist is a not the best practise.
Can anyone point to code or a study that says otherwise? I would have though that there'd be a consensus on this, but seems to be a real split here split. This is one that would be nice to come to an agreement on. Again I'm by no means an expert on framing, just trying to figure out where to drill my next set of holes. ;)
I'm with you. it's what I've always gone with and never seen print otherwise until this thread's opinions
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GreatWhite:
<!----><!----> <!---->
You Should not drill or notch the center 1/3 of the span of a solid wood joist (2x10, etc).<!----><!---->
<!----> <!---->
Woodrow and a few other above were wrong.
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How do I know this? 1) failed inspections. 2) what it says in 2 building code books I have. 3) what I learned in school in preparation for by GC exam.
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If you want some more info here are a some links:
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First, John Sr quoted IRC 2000 in the above posting: 66760.29
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My previous link with pic was also from IRC2000 that you already looked at: http://www.johnstonnc.com/files/inspections/spanchart.pdf (p. 5)
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The center of the joist span is a prohibited area in most codes because this is where the most bending stress is exerted along the evenly loaded span. This is explained on page 9 of this document: http://www.awc.org/HelpOutreach/eCourses/MAT105/Section05-Floors.pdf If you only look at one of my links look at this one!!!!!. Pages 8 - 10<!----><!---->
<!----> Page 11 goes on to say that center span drilling is premitted under some codes, (none that I have found), but also gives specific limitations if you have to drill in the center of the span. Page 13 of this document: http://www.woodsource.org/pdfs/woodsource_-_spring_2005.pdf
“Under Notching and Boring of Joists”
Page 7 of this document refers to BOCA 2000: http://www.heatedbathroom.com/pdfs/SunTouchUnderFloorInstall.pdf fourth paragraph
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Section 313.11.2.2 of this document: http://www.pprbd.org/codes/2000UPCAmendments.pdf
Which involves Uniform Plumbing code.
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On this web page under “Plumbing”: http://www.motherearthnews.com/DIY/1987_January_February/A_Decision_Maker_s_Guide_To_Attic_Remodeling
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Is that enough info to convince you? Joist drilling and notching is also covered in the International Mechanical Code, although I do not have the book or an exact reference.
<!----><!---->
Edited 12/10/2005 9:00 am ET by Matt
Having been a general purpose carp working on foundations to roof framing and everything in-between, I've been working next to and helping all the other specialty trades.
The worst offenders are the inexperienced heating guys. We've walked up and seen entire joists simply cut out and tossed aside. Those are times when we'd be pissed if it wasn't so stupid as to actually be funny. "Um...er...ah...we actually need that."
Electricians drill small holes so they aren't usually too much trouble. Although I've been surprised lately that many young kids who have never done anything but new residential construction don't even own a fish tape and ask to borrow mine when pulling an off-kilter wire. Tricks to pull wires in bizarre places during remodels has helped a great deal when problems arise in new construction.
It's interesting how even old pros have certain types of jobs they like and know a lot about, and other jobs that they are clueless about. Wiring builtin cabinets or the maze of under/over cabinet lights seems simple to the finish carps, but once in a while we'll get an electrician who just scratches his head.
Our main complaints are that electricians can't cut nice looking holes in anything. A new outlet in finished drywall always seems to end up with a stray saw cut peaking out from under the cover. That outlet on the end of an island cabinet--forget it. Never let an electrician cut any finished surface, no matter how badly they want to.
The plumbers probably end up asking the most questions and require the most attention. At least they know to ask--usually. Luckily we have always had good relationships with plumbers and tell them constantly to ask us if they have a question about what can and can't be cut or moved. Usually they come up with a solution to a problem that requires more cutting than if we solved the problem so instead of taking what they've requested at face value it's always worthwhile to think through it for ourselves. The high quality plumbers are often also the slowest and move at the speed of smell.
To their credit, good framers usually put joists in the correct place and it's the odd situation where something dramatic has to be fixed. Unfortunately, if there are stair stringers included in the framing package we usually give them a 50/50 chance of being right and 80% chance of actually being close enough to fix. That first step is tricky!
Anyone who has cussed a hole driller should have to install the 4" insulated ductwork for one of those whole house exhaust fans. Three bathrooms, two stories, 5 individual ducts running to the attic, 12" oc joists, fan in attic, 150' of duct, lots and lots of 5" holes. Dang, that was a duzzy.
Cheers,
Don
Edited 12/9/2005 10:44 pm ET by IdahoDon
Why don't we all just reverse it for a moment? I'm going to do an add-a-level on a house for Mr. and Mrs. Homeowner with no GC, they are the GC's but we're going to sister the new joists up against the old ones. Now there are wires and high hats running everywhere. Plumbing and Duct work everywhere in the ceiling joists that I have to run my new ones straight threw.Do I just cut everything out of my way without telling them to get their electrican/plumber/hvac guy in there? Or do I tell them to get everyone in there before I start?. The answer is very simple. These guys wouldn't like it if I just came in and cut everything.I'm doing a addition for a GC and also remodeling the inside of the house demoing walls and taking walls out and putting microlams in and ripping windows out and moving them over 4' and putting new headers in. Ripping out the bath on the second floor and moving it over 6' to the left. You know little stuff like that.Now once I'm done demoing everything. Wouldn't it be nice to call all the subs over to discuss where all the wires, plumbing and hvac can be cut nicely and I can discuss with the plumber how the bath was moved over 6'and I can cut out some joist for him and double up the joists and install headers with hangers making a plumbing box for the plumber so that he can run his new waste line 6' over in a nice open box that I can build for him so he doesn't have to drill holes in all the joists. Or maybe I don't have to make a plumbing box because he can run the waste line right down the wall on the first floor that's underneath us.Well, since we were all there and figured it out together as a team. I will make their job that much easier and when I see them on the next job we'll all shake hands and say what a pleasure it will be working with each other again.Joe Carola
Edited 12/9/2005 11:31 pm ET by Framer
That is what i was looking for. I knew I had a doc on my PC somewhere that prohibited drilling in the center third, so I was wondering if I'd lost my mind when everyone kept saying that is the best place for it.
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Am I missing something? Maybe I read through too fast, or was distracted.
I can see the language prohibiting notching in the center third of span, but nothing that prohibits holes.
>> I can see the language prohibiting notching in the center third of span, but nothing that prohibits holes. <<
Center third of the span joist boring is prohibited in 2 of the code references I posted earlier both from NC. Maybe it's just a North Carolina thing... We use a modified IRC 2000 but it's sometimes difficult to tell exactly what was modified. We had it in the previous CABO code too, but again that was modified. I'm very curious why NC felt that change was a good idea when it appears that not much of anyone else thinks it necessary. It will also be interesting to see if it is in the new code, which I think we get mid next year.
Either way, I don't think it's a good idea unless necessary.
True, open web trusses are the best way to go, but a little while back I did some pricing and from low to high $ it went: 2x10 -> I-joist -> Floor trusses.
Floor trusses? So what's money for if not to do it right?
Well, in that case, who needs any stinkin' joists anyway, let's just use steel I beams for everything.
I guess so. one of those docs he posted said no drilling, just like he quoted. I have had another, but think it is in the ohter PC.
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But it doesn't say drilling is prohibited in the center third, it says notching is prohibited there. (Just as the IRC 2000 R502.8.1 says). A good part of all this discussion is people not making that distinction.
Here's the sticker Joe
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Good chart -- thanks.
This thread is getting as funny as the dmix threads!
I'm so confused I've decided that I'll simply never bore a hole anywere!
Come to think of it, I never have!
blue
There's never been anything boring about you Blue
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i'm at a loss for an explanationYou can email sysop about it...[email protected]
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>> Someone said to disable my windows pop-up protection and my security software pop-up protection. I did this without results. Bummer. <<
Are you sure you don't need to reboot to make the changes fully effective?
The largest holes permitted in joists are always in the middle third of the joist width and in the center third of the joist length. There is more stress on the outside thirds of a joist than the center third.
"There is more stress on the outside thirds of a joist than the center third."
Not exactly.
At the ends you have all shear and no bending. As you move towards the center it becomes all bending and no shear.
In the center, the top of the joist is in compression and the bottom is in tentsion. The center 1/3 just has to tie the 2 together. That's why holes are allowed in that area.
You can do anything you set you mind to. As long as you have vision, determination, and an endless supply of money.
Right, horizontal shear changes directions exactly in the middle of the span. Progressive failure starting from an end is the thing to worry about.
-- J.S.
I'm not a pro so take this as more of a question. I was taught by a friend who I believe to be a terrific GC that the best place for a hole in a joist or a beam is at the end in the upper third of the width. Comments?
I agree about putting the holes in the end third but also believe that bearing walls above play a role as well.Am I wrong?
Bad news. You were taught incorrectly.
A floor joist undergoes two stresses: bending and shear.
Think about a joist 30 feet long with each end sitting on concrete. Now put a 100lb. block anywhere along the joist. The shear stress is 100 lb. no matter were you put it, but the bending stress gets more and more as you move the weight from one concrete wall towards the middle. However the bending stress is felt not at the middle, but at the walls. In other words, if this joist is going to fracture due to bending stress, it will fail at or very near the walls.
This means that you do not ever want to weaken a joist by drilling holes near the walls (or any other important support). Holes in the middle of the span weaken the joist the least.
Now in any joist resisting bending, the top of the joist is in tension and the bottom is in compression. This is why I-joists are stout at top and bottom and thin in the middle. The absolute middle of any joist feels no bending at all. That's why this is the perfect place to bore any needed holes.
In practical application in residential building, shear stress is almost never a limiting factor. You could use 2X4 lumber for floor joists on a McMansion and not over stress in shear, but the floor would fail by bending into a pretzel the first time ten people showed up for a party.
So in summary, if you have to bore holes in a joist, put them always in the middle of the joist when possible. In the middle of the span when you can, and in the middle of the thickness of the joist always.
Chris
Oops. In any joist in bending, the top is in compression and the bottom is in tension.
Edited 12/7/2005 11:53 pm ET by ChrisB
ChrisB- any problem drilling a small hole in the end section of a joist that sits on top of a bearing wall? Or would you be worried about it being a potential place for a bending stress crack to start?
Codes give clear rules about where holes and notches are permitted in joists. These rules are based on the calculations used in these same codes to set the span tables for the joists. They also take into account the nature and size of defects permitted in the grade of material used- defects which act the same way that holes and notches do.
If you are using engineered I-joist, there is no problem drilling a small hole in the joist where it sits on a bearing wall.
To quote from Boise Cascade's I-joist installation manual, " A one and a half inch round hole may be cut anywhere in the web. Provide at least three inches of clearance from other holes."
If you are using standard 2X lumber, I think you are still OK, just put the hole somewhere near the middle if the joist.
Chris
Chris you say "However the bending stress is felt not at the middle, but at the walls. In other words, if this joist is going to fracture due to bending stress, it will fail at or very near the walls."
If you put a board between two saw horses and jump on it, does it break at the saw horse or in the middle? I think I know the answer to the question.
I think he means that the bending stress is not felt at the middle DEPTH of the joist. Bending creates compression at the top & tension at the bottom.
About the bending stress (moment of inertia), if the weight is in the middle and it fails at the ends, why does a twig snap at or near the point where a knee is resisting the force applied by hands pulling on the twig's ends toward the knee? Also, the 100 lb weight is live load, so you need to consider the dead load in order to accurately calculate the shear/moment forces. If a weight or force is applied at the end of a joist, the shear is at max and moment is at minimum, assuming a point load. As the weight moves toward the middle, the shear is shared by both end supports and the moment increases till it reaches its maximum at mid span, where shear is reduced to its minimum at that point, assuming consistent cross section in the member. Then, the process reverses relative to the original end as the weight moves toward the other end.The amount of tension and compression in a joist is progressive. More tension at the bottom, less as you approach the center, then compression goes from about zero to maximum at the top. There is strength in flexibility.
"I cut this piece four times and it's still too short."
You and Shaken not Stirred are dead right and I'm dead wrong. I don't screw up too often, but when I do, it's usually a doozie.
I was going to post a correction to my post, but you guys beat me to it. True confession: it has been 45 years since I actually drew a bending moment or shear diagram and did the calcs.
My statement as where to drill a hole in a joist is OK, my description of the failure mode of a joist is flat wrong. An evenly overloaded joist fractures in the middle as you guys state. For some reason I was thinking of a joist as two cantilevered beams that happen to meet in the middle. It's not, of course.
Mea Culpa.
Chris
I don't know if there are any photos online, but a great example of a moment diagram is a side view of the Hoan Bridge, here in Milwaukee.
"I cut this piece four times and it's still too short."
Chris, not a problem your honesty and humility is refreshing! All are friends here until someone gets an additude.
I'm no framing expert, but I think we all agree that the center of the joist (depth) is the best place for holes.
Could someone explain clearly why the middle of the span would be a better place for holes than the outer 1/3rd's? I can understand why you wouldn't run holes underneath bearing walls, or through squash blocks, etc, but why put them in the middle of the span where the bending moment is greatest?
On a member with a uniform load along the span length (most joists in a house), the bending stress is max at center span and zero at the supports. Shear is zero at center span and max at the supports.
Bending stresses are greatest at the tops and bottoms of a memeber's cross section (hence I-joists) while shear concentrates at the center of the section. Therefore a hole through the center of a section at midspan is passing through a point of negligible to no stress. The opposite is not true at the tops and bottoms of a member because of bearing conditions at the ends of a span.
Members with point loads are a little different since the maximum shear can be at the point load (depending on how many point loads and the magnitude of each load)....that's not a mistake, it's rustic
kicker:
I am no expert again, but I think in physics you learn that in the center line of any beam their is ZERO tension and ZERO compression. So drill away! As someone else mentioned, this is why I-joists work. The webing is of no strength, just a separation for the tension and compression arms and to stablize the mess.
Bending moment in the verticle and horizontal center of teh beam is ZERO.
thank you for all of your input! It helped greatly and was just plain interesting (your structure discussion was right on). The problem is solved (I went out to see it today) The problem ended up being 2 fold. The small holes near the bottom of the joist, although probably not critical, just didn't meet code. My recommendation was a Simpson stud shoe on each joist. (It did cross my mind that the inspector was looking for a nail guard - in the end, I don't think so)
The greater problem was a sanitary pipe right at the top of one joist. this also was a violation since it was a little too deep to be considered a notch (d/6). In that case the pipe has to be moved and the "fix" agreed on was one discussed - 48" full joist height plywood glued and nailed to each side.
Thanks again!
PS - The "G" in Garch stands for girl...
"PS - The "G" in Garch stands for girl..."Oh Boy, are you in trouble now (G!!!)
PS - The "G" in Garch stands for girl...
Well, you could fill in some profile info, you know <g>
The gavel-drivers went to considerable trouble to put the dark gray "update profile" at the top of the screen and all <g>.
Don't forget that you can put pictures (if you care to) in the Photo Gallery (this may be a less-obvious folder if you are new here, as your are).Occupational hazard of my occupation not being around (sorry Bubba)
I quickly mocked up a 2x10 joist in a simple FEA program, and the attached photo was the result for holes on the outer 1/3rd, and the center of span. Still nothing that would indicate critical failure, but I still don't understand why the center of span is more ideal place for holes, the model showed a larger amount of stress when it was located there.
Any way you look at it, the small holes aren't going to cause the joist to fail, be it in the middle or ends of the span, I think this comes down to what is the best practise. I've allways run the holes towards the outside, but would like to change to using the middle of span if thats the better way.
Now if it were a fink truss, I'd agree that the outer edges are a big no-no. :)
Edited 12/9/2005 2:17 am ET by kicker
Edited 12/9/2005 2:18 am ET by kicker
Forgot the drawing:
There are materials testing labs that have done all of the empirical testing for every framing member you can think of, and probably a bunch that you can't. There's one in Madison, WI and another at UW-Stevens Point. All of the lumber companies use or have used these labs to determine safe working loads for their products as well as real-world situations caused by some dork who just has to cut the top 6" out of a 2x10 in order to get his drain pipe where he wants. Usually within a foot of a big run of wires. In the middle of a joist. Or, he takes out the bottom 1/3 near the end so he can maintain the pitch of said drain pipe.
"I cut this piece four times and it's still too short."
these questions about the proper location for joist boring brings up another thought:
It amazes me as to how many people involved in building/remodeling do not have the code book for their state, much less read it... They rely on word of mouth or "this inspector told me this" and "that inspector told me something else".
Then you have the group of people who not only don't own a code book, but think they can reason their way out of anything... Usually with a number of 5 syllable words and long explanations... I just smile...
Your state/whatever doesn't have a code book? Fine - go get a model code book like maybe IRC or something from an adjoining area, start reading and start learning.
Even though we are all grown up now, homework is still required...
Ok, I must be really slow, cause I read your post three times and still can't figure out what you meant. I was just showing a simple model, Your right that real situations act differantly than models do. You mentioned lab results that show every type of framing failure, so what did those reults say, middle of span or end 1/3rds? (for a basic floor joist arrangment)
Not trying to start an arguement here, just trying to understand why, and which method is better.
I don't remember what the results were, but This Old House has gone to both of the labs in WI to show what they do. I think it was just informational, not load-specific. I really think it will depend on how it's loaded, too. You know how remodelers (more specifically, interior detonators) are. Interior designers have to know how this stuff goes together, so they usually get it right when they move a wall to an unsupported location. They know that support will need to be added, but decorators just want it to liik pretty. Also, it's been 30 years since I took a materials course, but I still have my books. I'll look it up when I dig the main book out, since they still use it (with updates) in engineering schools. It cost me $75 in 1975, I can't imagine how much it is now.Which part is hard to figure out?"I cut this piece four times and it's still too short."
Edited 12/9/2005 1:46 pm by highfigh
For a simple beam, uniformly loaded and supported by end bearings, shear stress is max at bearings, and flexural stress maxes at center. This has been covered by others in earlier posts.
Shear stresses are trying to separate fibers horizontally, equally from top fibers to bottom. A beam's web is seeing those stresses out near the bearings, and is experiencing decreasing web stresses as distance goes out to center, where they are zero.
Take a look at the structural steel used in highway bridges. You will often see web stiffeners used out near the bearings, but never at the center. The stiffeners are there to prevent the web crippling that can occur from shear stress.
Note also how TrusJoist and other I-joist manufacturers require web blocks in certain applications, but never out in the center of a beam, unless the blocks are there for header attachment.
Removal of web material by placing holes through beams thus weakens beams more if the holes are closer to the bearings, than out in the center region.
>> Note also how TrusJoist and other I-joist manufacturers require web blocks in certain applications, but never out in the center of a beam, unless the blocks are there for header attachment. << Right - and that is because the blocks are placed below load point like under load bearing walls - which are not placed in the center of the span. Perhaps I misunderstand what you are trying to say?
>> Removal of web material by placing holes through beams thus weakens beams more if the holes are closer to the bearings, than out in the center region. << This is true various types of I-beams, including TrusJoist I-joists, but is not true for solid sawn joists - which is what this thread is about (I think). Although it is true for any joist that you don't drill directly below a load point and the downward compression of the load will (thoeredically) crush the joist/I-jost/etc.
Likewise an I-joist flange is never notched, where as edge noching is premissable with solid sawn joists if done properly, so, we see that I-joists use entirely different rules for penetrations than solid sawn joists.
All: another rule of thumb: a floor system header (beam or girder) can never be drilled (anywhere) without an engineer's written approval.
Edited 12/10/2005 11:51 am ET by Matt
Matt, the principles of shear and web stresses apply, whether we are talking about beams made from OSB and PSL (some I-joists), steel, or solid sawn lumber.
The web of a wideflange steel member, and that of an I-joist, out near midspan in the region of max flexural stress, is acting as a spacer, keeping the flanges spaced. It is experiencing minimal shear stresses, so it is OK to remove some material periodically, withing limits, such as holes for mechanicals.
The same can be said for a 2x10, which has much more web cross section than necessary. It would be foolish and uneconomical to mill solid lumber with sections like I-joists.
Near bearing points it is a whole different story.
Gene:
I don' know if you are disagreeing with me or we are talking apples and oranges...
Again - as far as I know, this thread is about solid sawn lumber. I have presented a number of resources to support my statements: 66760.82 Please supply some supporting data/third party articles/etc for your theories specifically relating to solid sawn lumber. Leave I-beams and such out of it, as that is not what this thread is about.
Mean time, I'll just stick to stupid stuff like passing framing inspections...
Thanks,Matt
Matt
I read all of the resources you quoted and they all are talking about notching not being allowed in the middle section of a span.
They are not talking about boring a whole except to the extent it needs to be more than 2 inches from the edge.
I could be wrong but that is how I read them.
Dan
After reviewing you are right: some of those docs deal more with notching, however from: http://www.johnstonnc.com/files/inspections/spanchart.pdf "Do not drill in the center 1/3 of the span" That happens to be one of the jurisdictions I build in.
And from the NC building code (I do not have an online electronic reference): note below figure R 502.B "1. Do not drill in center 2/10s of joist span"
Granted many codes do allow drilling in the center of a joist span (although the code I build to does not), I'm OK with that - what I do have a problem with is those who said the center section of the span is the strongest portion and the best place to drill - that is WRONG. The center of the span is the part with the most load on it - with the exception of the supported ends. This is explained in: http://www.awc.org/HelpOutreach/eCourses/MAT105/Section05-Floors.pdf the top of page 9.
So, since we endeavor to build at or above code, drilling center span should at the very least be avoided, if possible.
OK. The reason the code allows holes in solid sawn lumber in the end thirds (as well as in the middle third) is that solid sawn lumber has a whole lotta beef in it's "web" area, as compared to I-joists.
That is why the I-joist makers restrict holes in webs in outer thirds of length, whereas the code for solid sawn allows holes.
Shear stresses affect the "webs" of beams moreso than flexural stresses, the "webs" being that part of the cross section at the center, not near the top or bottom.
Look at how much section there is to the two sideplates that are used to brace I-joist webs. A solid sawn joist has that section everywhere, and for that reason, can handle more shear stress than an I-joist of equal depth.
Do you think that drilling solid lumber joists center span is a good idea or not?
Holes anywhere along a 2x joist are permitted, provided their diameters don't exceed 1/3 of the joist depth, and also provided they do not infringe the 2-inch-from-top-or-bottom-edge region.
The codes don't get as specific as they should, however, about hole spacing. I would not want a series of 3-inch holes in 2x10 joists spaced as close as, say, 1-1/2-inch apart, but the code does not speak to that.
Yea - but I asked you what you think best.
Better? Mechanical chases below the joist planes. No holes, no notches.
Best? Open web floor trusses.
How is shear trying to separate fibers horizontally? Shear is caused by two oppostite forces acting at or very near the same point on a material. It doesn't need to be a framing member for shear to occur. Scissors, or shears, are the best example of this. In framing, when a joist or other load bearing member is installed, the shear force will be highest where there is support under it (at the perimeter of the plate or whatever is in contact). The downward vertical component of the force is countered by the neutralizing upward component of force in the same area. The structural member needs to be able to resist the effects of these, or one force will win out over the other, causing the member to fail. When this type of failure occurs, the fibers of wood are torn in a narrow band (relative to the length of the member) along the line of the greater force. This does not happen in the middle of the span unless there is support under the failure zone. If a member fails in the middle of a span and is unsupported, it's due to the material failing doe to tension, not shear. By "web stresses". you mean shear, right? You're correct, the shear is highest at the bearing points of the beam. However, the moment of inertia is highest in the area of the span where the force is concentrated. Evenly distributed, it would be at mid-span. This is where shear is at its minimum. Conversely, the point where moment is minimal is where shear is at maximum.
"I cut this piece four times and it's still too short."
> How is shear trying to separate fibers horizontally?
If a beam is supported on both ends and loaded on top, it tends to bend downward. That puts the top edge of the beam in compression, and the bottom edge in tension. Those forces therefore try to split the beam horizontally.
Consider an experiment:
Take two sawhorses, a 4"x8" and five 2"x4" each 16 ft. long.
Set the 4x8 on edge supported on the ends by the sawhorses. Stack the five 2x4's on the flat alongside it. The 4x8 is 7 1/2" high, solid wood. The stack of 2x4's is also 7 1/2" high, but has four horizontal planes having nearly no shear resistance except for a little friction. Other than that, the solid beam and the stack each contain pretty much the same amount of wood, in pretty much the same size, shape, and orientation.
Push down on the middle of the 4x8 with both hands. It deflects very little, hardly enough to notice. Push the same way on the stack of 2x4's, and the stack bends downward easily and noticeably. There's virtually no movement between the 2x4's right in the middle, maximum movement between them is at the ends.
That's how bending causes horizontal shear in a beam.
-- J.S.
The fibers separate due to the tension, starting at the bottom and they continue to fail in an upward direction, assuming the force is downward, but in structural analysis, shear is due to opposite forces impinging on one point or along a line. When a structure is analyzed, shear occurs at attachment and support areas and moment of inertia is where the member flexes the most. In your example with the stack of 2x4's layed flat, yes, they slide when you push down because they aren't fastened together. That's not what is meant by shear force in structural engineering. If they are attached weakly, the joint would shear, but it would be due to flexing. The 2x4 on edge is stronger than one layed flat because its dimension perpendicular to the force is greater.
"I cut this piece four times and it's still too short."Edited 12/12/2005 7:21 pm by highfigh
Edited 12/12/2005 7:23 pm by highfigh
Highfigh,Semantics shall be the end of us!What John Sprung was illustrating with his elegant visual was what happens in a solid beam/joist when the wood cracks along the grain in response to shearing forces along the length of the beam (which naturally occur as a byproduct of bending stress). The proper term for this phenomenon is "shear failure." It is a very common failure mode in overloaded solid-sawn wooden beams.Hope this was helpful.Bill
It's not semantics, it all about how it's worded. lolThis is from a quick reference link on the 'net. shearn 1: (physics) a deformation of an object in which parallel planes remain parallel but are shifted in a direction parallel to themselves; "the shear changed the quadrilateral into a parallelogram" We should probably move this to a "Yes it is/No it isn't" thread. HA!
"I cut this piece four times and it's still too short."
Exactly. The definition you found perfectly describes what occurs with the adjacent wide faces of the 2x4's in John's example; "a deformation of an object in which parallel planes remain parallel but are shifted in a direction parallel to themselves" This also neatly describes what occurs in a straight-grained joist that suffers shear failure under load, which I believe was John's point when he posted his illustration of the principle.Bill
I don't believe so.Never serious, but always right.
middle of span? You writing your own codes now?
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I have no idea what you are talking about. Was my advice correct or not?Never serious, but always right.
I don't believe so, but the majority of theis thread says I'm wrong. I gotta find a document, then be back - maybe with an apology
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If I were you, I wouldn't admit it even if you are wrong. Especially to this bunch.
I'd say the sun was in my eyes or my wombat crapped on my differential calc tables, but never pi$$ into the wind, let anyone see ya dancin naked to hip hop, and never ever admit your wrong.
Never serious, but always right.
I found enough to assure myself that I'm not wrong - Whew!- but not the doc I am looking for to prove to everyone else.
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I think the whole point for failure has been missed.
This thread has focused on the structural "changes" brought about by the holes bored by the electrician. I do not believe the issue is structural at all.
Your original post says the holes used to feed wiring are 1-1/2" from the bottom of the joists. The inspector says the hole needs to be 2" minimun from the bottom of the joist - the stated reason for failure. Although the inspection was said to be a framing inspection - the inspector was looking at other items also, including electrical issues. We call this a "close-in inspection", after passing this one we are allowed to insulate and start covering things up from inquiring eyes.
The NEC (and from the inspectors remarks, the IRC also) says that holes bored through joists for the purpose of running wiring must be a 2" minimum from the bottom of the joist. I believe this failure is a wiring protection issue, not a structural issue.
The "cure" (provided it is acceptable to the inspector) may well be as simple as protecting the wires with a nail plate for each hole. The nail plates would be nailed to the bottom edge of the joist directly below the wire/hole - granted it will be a lot of plates on a lot of joists.
The plates are steel and protect the wire from errant nails / screws used to attach future wall / ceiling coverings such as drywall. Plumbing pipes require similar protection. Plates are readily available in a variety of lengths - even your local big box carries them.
I think the inspector should be queried as to the real reason for failure - structural? or wiring protection? If wiring protection, then ask if nail plates would be an acceptable cure. In any event, it was very amateurish on the part of the electrician. My vote goes to letting the electrician bear any and all costs associated with the cure.
Jim
Never underestimate the value of a sharp pencil or good light.
Edited 12/8/2005 8:07 am ET by JTC1
I was always under the impression that the two inch minimum set back from the edge of the joist had nothing to do with structural integrity of the joist, but was a way to prevent anyone from nailing through the wire in any subsequent work. If so, just move the holes farther from the edge.
>> I was always under the impression that the two inch minimum set back from the edge of the joist had nothing to do with structural integrity of the joist... <<
She said the framing inspection failed (that's the name of the thread). And yes it does effect the structural integrity of the joist.
I think that that the electrician is the one that you should ask, since he caused the problem its up to him to provide a solution.
"...electrician is the one that you should ask, since he caused the problem its up to him..."isn't that like a judge asking the rapist what his sentence should be?
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I don't think that your analogy fits. All I'm saying is that the electrician should come up with a fix that meets code, it should be his time, effort, and cost to rectify, not someone else. I don't think that you can fix a rape!
I was pointing out that he should not be specing WHAT it takes to fix it.but I don't think my analogy was that far off. He has raped the framers work.
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We are on the same page now. "May the force be with you."
Maybe someone already mentioned .... didn't read all 113 posts...
If code says 2" from bottom and you are 1.5" then your solution should only have to get back to the strength with the hole at 2" from the bottom. This could be a big difference then a couple posts I read that seemed to lean toward getting it back to 100% strength.
Good luck.
Stu
check out Metwood (they make joist reinforcement products)among other building products. Hope it helps.