Hello All – hope you’re enjoying this holiday season and not working too hard
I have recetly replaced my decomposing sunroom off the back of my house up here in the woods of NH with a nice insulated version, and have been planning on taking down the old exterior wall to bump out my kitchen and living room. Well yesterday was the day or ‘wreckoning’ and I took the kitchen side down with the help of some bribed friends after supporting the 2nd floor with some posts and jack studs. We lifted our 15′ beam consisting of 3 engineered 2×12 LDL sheets (in effect actually a 5×11.5 beam) into place and everything went about as well as hoped. On one end of the beam we have a 2′ stub wall supporting it, however, the building inspector/consultant recommended just 2 2×6 boards holding it up on the other end. This seemed fine in theory – but seeing it in the flesh makes me question the compressive strength of these boads – considering that a good portion of my second floor will be sitting on them.
So – do I trust what I currently have in place or pop out anopther stub wall on the far side as well? We still have the supports in so can pretty much play around a bi more if we feel like it. Another stubby wall would kind of interrupt the aesthetic flow of the new kitchen, but I’d sleep better at night – especially since it is directly beneath my bed!
Thanks a lot – all opinions welcome!
Replies
It's hard to get solid engineering advise online because of liabilities and hazards.
Bur generally speaking, the doubled 2x6 pot cocerns me less than the spane of 15' for the tripled LVL. I can't see all the loading, but that seems on the verge of maxed out, so I'm sure that a stub wall to shorten that span can only help, depending on what ity is transferring load to under it
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Thanks a lot - I actually mis-spoke. The total length of the beam is 15', but the open span is only a hair over 12' taking the one stub wall into account. We also lagged the 2x8 anchoring all the cieling joists of the addition to the side of our beam - so that gives it a little extra beef.
So we went ahead and just added a 1x6 between the 2x6's on the far end for a little extra support. After attaching all the hangers to the floor joists, we dropped the jacks and posts down and didn't hear a single creak when it loaded up! Feel pretty confident, but I'll be taking it a little easy in the bedroom for a while if you know what I mean.
So now it's on to the living room today for round two!
When we unload jacks, we use a laser or a string to know if it stays straight. Sounds don't say too much, especially the lack thereof, indicating a likely false positive.That span sounds much better, but arte the end supports continupus to foundation with blocking below?
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That laser/string is a good tip - I'll be sure to use it on the next go-round
And yes the end supports are blocked down to the cement foundation. They are also tied to another 2x6 on the end for some more stiffness which ties in to the upper rim joist and the end of the beam itself - so I do think we'll be ok. But I'm sure the inspector will have something else to say when he comes to check it out
Thanks for all the advice!
"..."the open span is only a hair over 12' taking the one stub wall into account"
Is the entire stub wall bearing? If not, your beam is still spanning 15'.
Any chance of getting some pics of the situation?
One man with courage is a majority. [Thomas Jefferson]
Here are a few pics. The picture "BeamR"shows 2 2X6s and a 1X6 under three 11-7/8" LVLs, the outer 3rd 2x6 goes under the original rim joist and is tied to the others. The rim joist is also tied to the beam and the 2X6 in the new construction area is tied to all of it as well."BeamL" Shows the stub wall and is tied to the original constuction.Both areas are blocked to the foundation for the full length of the verticals.
12'5" Open span - the LVLs were spec'd by Boise
Although I have woken up in some strange places - I hate to wake up in the kitchen while still in my bed.
I am going to do a similar bump out of my kithcen this spring. And will need an LVL making a "T" intersection into another LVL, if possible to avoid using a column. Question, did the triple LVL come from the manufacturer put together, or did you assemble on site ? What was the total weight of that beam. How many did it take to put in place ? Did you have to beef up your footings at the bearing points ? Do you have an exterior photo ? ThanksRobert
Attached are the calculations for a job similar to what you are planning. DON'T use these figures for your job.
On what should have been the outside of a gable wall was an addition butted to the house by a previous owner. The ceiling joists were 2x6x20, running parallel to the gable. Had a noticeable dip, about 1 1/2". The addition was 15' wide.
Inside, the conventional framing rested on a bearing wall that bisected the house. The first section included the kitchen to the rear and the living room to the front.
The objective of this job was to remove the gable wall and the bearing wall between the kitchen and living room to create one large space, approximately 20x31.
LVL #3 was placed at ceiling height (flush) and the gable end wall was removed. 4x4 posts were embedded in the end walls and brought down through the crawl space to new bearing surfaces.
LVL #2 was hung from one side of LVL #3 and crossed over the center of the 2x6x20 ceiling joists of the addition to rest on a 4x4 post embedded in the far wall. The sagging ceiling was jacked up to meet this new strongback and then each joist was attached to the LVL with double hurricane straps (H2.5). No more sag.
The ceiling joists of the living room were supported on a temporary stud wall - this was before I got some post shores - and the ceiling rock was removed about a foot wide next to the existing bearing wall separating the kitchen and the living room. Since the joists overlapped the bearing wall I snapped two lines on the exposed ceiling joists and chain sawed out a section from 12 joists, leaving an intact set of joists still bearing on the original wall and the living room joists now floating, supported by the temporary stud wall.
LVL #1 was now lifted up between the joists and hung from the other side of LVL#3 and supported on the far end by a new stud wall. Had a nice tight fit. This one was set flush and the cut joists on one side and the joists still resting on the original bearing wall were hung with joist hangers.
After all the nailing and strapping was completed the temporary stud wall and the original bearing wall were removed. Ceiling was patched and finished. One of these days I might find the pics I took or just go back and take some new ones.
To answer a couple of your questions:
New footings were needed to take the weight transfered outward to the new bearing points.
It took two people to lift each section into position, and
The LVL's are built ups. Each is 1 3/4" thick. The LVL's supporting the cut ceiling joists (replacing the center bearing wall) were 2 @ 9 1/2" deep. The main LVL was 2 @ 14" deep and the strongback was 2 @ 11 7/8" deep.
Attached is the outside pic after the sheathing. The foundation that the addition sits on was a 1980 upgrade when the government had tons of money to throw away on alternative energy improvement and houses a fantasitic thermal sink that is insulated and filled with stones. The original foundation is from 1976 and both are 8" thick poured concrete. I did not beef the foundation, but added solid blocking to the rim under all of the load bearing area.The LVLs are Boise 1-3/4"X11-7/8" Versalam 3100 that were spec'd by Boise at Lowes. I brought in a drawing and all the load requirements and *poof* after 31 calls and several days a magical spec appeared. Actually, they spec'd it wrong the first time with a tributary that extended the entire depth of the house. So make sure you get all the details in the drawing, leave nothing to the imagination, and talk to the inspector first.They sell the LVLs by the linear foot and so the other side (3 extra on the floor) needed to be 13'-1" and I ordered 14 footers they delivered 16 footers giving me some extra room to play, but I think it is a roll of the dice.Assembly is required and batteries are not included. The Spec gives a diagram for assembly (nail size, spacing). The weight...HEAVY! Especially over the head while fitting into a tight area. Maybe 80# each, so the 15 footer is about 225#. Luciky I have 5 friends that helped lift with an offer of all the Beam they could drink and a grill full of Elk, Ostrich, Buffalo, Kangaroo, and Alligator. Of course they helped with the rest of the tear down and installation. More JBeam required for the other side and I highly recommend the Elk and Kangaroo. Just don't tell the wife what it is.
Thanks for the reply, so Lowes offers this design service if you buy from them ? not a bad deal. I'm sure they did not give you any direction on foundation modifications. I am pretty sure I am going to have to add a column footer at one end. I am also stripping some brick veneer where I tie in so I won't have to carry the brick above the opening. Thats ok because there is already some cypress siding that I can match.
Robert
Actually, HD and Lowes offer the service both from Boise Cascade here in NH. I had both on the phone in a price war. You do not have to purchase from either though.The big boxes don't know much about the construction, hence my post here and the multitude of calls to get the spec straight. They had no idea of what the spec was except it looked like an important piece of information. The boys that post here offer some good advice and the inspector here has been hepful with other aspects of the build. I do live in a town of 4100 folks so he has a little time to spend with yahoos like me.
Boss ain't likely to download pictures that big. I normally don't eitherYou got hree extras there. Guys at HD miscount?
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I wish HD could count that way, but no extras were handed out when I paid for them. The other 3 are for the other end of the house, a bit shorter than this one to open another room.
Piffin is right - I don't normally download pics that big. Dialups are a pain, but that's all I have.If you have full bearing to the foundation at the END of the stubwall, this doesn't bother me as much as it originally did. But if the bearing is ONLY at the ends, then I think the beam is undersized. The double cripples at the ends don't bother me much. LVL has a really high compressive strength per square inch. The 2X6s are restrained within the wall, so buckling isn't a problem. If you want extra insurance, and a 3rd cripple. But no way would I believe you needed more than that.BTW - Did you get a printout of the beam design from the supplier? That would show the loading used, the minimum bearing required, and the expected deflection.
The trouble with bucket seats is that not everyone has the same size bucket.
Thanks Boss, you are right about the print out, I looked right past that. They give 1-1/2" bearing for each end. Total deflection of 0.395". With bedroom upstairs and 85 lb snow load requirement the 1-1/2" bearing seems pretty short to me, but I think I got it covered here.
Warp speed warps the mind. Next time I will use smaller pics.
I'm with Piffin - spanning 15' with a beam that shallow is questionable, at best.