Attatching a deck to house ..not at rim
mbr440
| Posted in Construction Techniques on
Hello all ..
I will be building a 12 x12 deck 10ft above grade, 2×8 pressure treated hemlock/fir josts.6×6 posts.
integral beam at outer rim with blocking and 2×6 deck surface.
The house has Vinyl siding and 3/8 osb sheeting and 2×6 studs. I want to attach the deck below the rim joist on the second floor.. Should I cut out the sheeting and block between the studs and re sheet.. Lag bolt and adhesive the ledger..etc.. Suggestions please.. A deck this size can potentialy hold allot of people..
Suggestions please.
Replies
I'd nail a 2x8 against house.....then find the studs and lagbolt into them using 3/8 x (as long as it takes to get plenty deep into the stud. I'd use hangers for the joists and sit them on top of the beam with an overhang of about 1'.....attach the joists to a layed out rim joist and then square and toenail the whole thing into the beam.
If I was worried (but I wouldn't be on a 12' deck) I'd attach a ledger under the 2x8 against the house.......
Edit.......forgot the flashing...definitely make sure you deal with any future water problems at the house
Edited 6/8/2008 8:21 am ET by jjwalters
I'd be worried. I had a client once that did his own drawings for a second story deck.
He spec'd 2x12's on a ledger attached to a cantilevered part of his house.
Not a big deal except that this was where he planned to put his hot tub.
I gave him my changes and told him that without an engineer I would only build to my specs.
I never heard from him again.
Edited 6/7/2008 3:57 pm ET by MSA1
I never put a hot tub on a second story deck and would,like you say need a bit more direction as to how big a tub vs load etc.......don't think it would be a good idea regardless........
It got better. He told us his plan would be fine because he showed the drawings to the BI (sans hot tub) and the BI said it looked fine.
take off the vinyl first
Run Bituthene behind the ledger location and 16" above it, with laps into the housewrap facing the right direction.
Then screw 4" x 8" x 2" blocks into each stud
Then lag through ledger and spacer block into each stud
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Couldn't he make it a free-standing deck? Have to cross brace to prevent racking and twisting.
i like the free standing idea also, build it next to the house but not attached, and hail for stout. cross braced like you suggest etc.
in my opinion the additional cost in a freestanding deck is offset by not having to remove/replace siding, flash, bituthane, etc.
if you had the framing open from the inside and were installing a big slider anyway it might be different, but if you don't have to make changes to the house and just want the deck i would make it freestanding.
Yes, probably preferable
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Thanks the reply's.. My main concern was the deck pulling away from the house if it was filled with people.. I like the freestanding idea.. however estecically maybe not what they are looking for.. I think I will use some p.t. plywood spacers screwed to the studs with the paper, membrane , flashing details mentioned.. and some lateral bracing from the posts to about midspan. I will do the same from the house to midspan as well. As a longtime reader of FHB I new I could count on some good info from its readers.
"My main concern was the deck pulling away from the house if it was filled with people."You want to be equally concerned about two other things.One is the fastenings to the house being too weak and letting that end of the deck fall straight down without ever pulling awayThe other is that water gets in and causes rot and mold in the house - very very common problem.I was also concerned about your original thought of letting it into the sheathing. That sheathing may be an important structural shear part of the house that you do not want to break.
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Good points.. I was confident in my detailing to keep the water out.. I was concerned with the shear and pullaway..
I would have replaced the sheathing after I had installed the blocking between studs...I did not want to mess with the integrity of the original structure but ... I wanted to know what I was attatching to. The main purpose of my post was to confirm if lagging into 2"x"6 studs on 16" centers would provide a safe, permanent attatchment to the house with proper water detailing..
I see references to concerns about pullaway on decks quite a bit, and I think they come from news reports of decks failing. Invariably, some other part of the deck, a post or beam, failed first to cause the deck to collapse. A properly built deck should not exert any significant horizontal force on the rim joist. I'd work on a strong shear connection and not spent too much time on pullout.
A lot of posters here champion free standing decks, which I like in theory, but would be interested in seeing real life examples as to how they dealt with the bracing required on decks more than a couple of feet above grade.
I tend to agree with you on this one..In my opinion it would need some serious bracing when ten feet above the ground.
mbr
i noted that you want to set the level below the 2d floor rim joistthis is a large step down from the 2d floor to the deck
why are you doing that ?Mike Smith Rhode Island : Design / Build / Repair / Restore
Not to answer for the OP, but any time I build a deck that might impede the view from the room behind I set it down 14". Otherwise the top rail falls right on the horizon when you are sitting looking out the window.
you know what? That's something I never thought of, but it makes sense...specially these days where you have to have balusters 6" o/c or less.....
true that... but people expect to step down ONE step ...
this requires TWO... and causes accidentsMike Smith Rhode Island : Design / Build / Repair / Restore
I believe some local codes call for a landing of some particular size if there is a drop of more than one riser.
Eric[email protected]
It's been a while since I looked it up, but unless it has changed our codes don't allow a single riser inside a dwelling. It has to be two. Outside the requirement for a landing depends whether it is an exit, or if the door swings out. Strange huh?
I had an old archy tell me once that if you are dropping more than th e one 7-8", you always need two more risers. One step only will trip people up going down.
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In houses from the 50's it was popular to have that single riser drop at the living room. Usually carpeted - you just didn't see it. I've taken a stutter step and lost the contents of the glass I was carrying many times over the years. I guess that's why they dealt with it in our code.
Installed the framework ..Stipped siding off and found ... 3/4" x 8" shiplap sheeting on 2x4 studs.. Which made it easy to locate the studs.. Fortunately there was a 5 ft header for a window on the first floor and and lots of studs to transfer load down for the 6 ft. slider on the second floor.. Tons of good material for the lag bolts to anchor.. Used a 2X12 ledger spaced out with the 3/4" p.t. plywood spacers.. after lapping 30 min paper etc and wraping the spacers with Blueskin..
The reason for the two rise single step is to get the deck closer to the ground.. instead of a large run of stairs.. This is a two tier deck with the second one down 4 risers and three treads.. and a smaller run of stairs to grade.
This arangement brings the back yard closer to the deck and gives a better view from the house..
I was planning on making the single step 11" and the full width of the 6ft slider..Any input on this.. ?
Thanks.
I find for a single step it's better to go a bit wider. Usually 3 2"x6", or about 18". You often stand on the step to pull the door, and it's nice to have a bit more room. I always make the step the whole width of the slider too. Which in a way doesn't make sense as one side is inoperable, but less looks somehow wrong.
I hope you mean the tread is 11" and not the riser of the step. An 11" riser will kill somebody going down and the old ladies will never be able to haul themselves up
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Typo... Yeah the riser is 7.5" and tread is 11"
Yep, I build one with a single step down in a piano/sitting room once as per plans. First time they were showing the room off, and old guy doddered over it and right on his face
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Mike,
I was going to inquire about the integrity of lagging to the studs. Seems a bit sketchy but what else to do?
I have one like this coming up. Three levels begining with a step down to level (A), then two risers down to level (B), then one more riser down to a landing to which the steps to the yard will be attached.
Level A I will get good purchase to the rim joist and the top two wall plates. After that I'm honking except for maybe catching a header here and there.
Eric[email protected]
the look of the freestanding will not be any different, except for whatever bracing is required underneath. you can just trim out where the deck and railing meet the house, no one ever need know that it is not a structural connection, just make sure when you do that you don't create a place for water to get in.
Last week, before I could install my clients' new patio doors, I had to repair the rotted subfloor and rim situation underneath 'em for the deck joists's's's were attatched with joist hangers, directly to the house's rim with no flashing or anything...
I would install a 2x8 rim as others advised. Run Grace Ice and Water shield behind it, lap the housewrap, and use a 'ledger flash' type 1 1/2 Z metal, which has a much higher back to it than reg Z metal.
http://www.deck-lok.com/ this product 'loks' the new rim to the floor joists. I've not used it but would if I had your project and your concerns.
Somebody makes a really nice composite spacer too, but I've made them before out of PT ply.
Have fun.
Pat
Definitely remove the siding as Piffin advises and most people suggest.
I do run Ice and water shield or a real good energy wrap under the band. (You just need to make sure water can run thru if it does get past the flashings)
Install the band board. (consult code or a designer or FHB for the correct spec's for attaching the deck. There was a good article a year ago or so re. how many lag bolts based on the span etc. in fhb that I have used as a reference)
Once the band board is on, a drip cap or Z flash should be put on top of it, folded down at the ends if possible to ensure no water gets behind band board. Cant use aluminum if you have ACQ PT wood. There is a vinyl Z flash that my local siding supplier carries that I used once that was real nice. No concern about it getting eaten by the ACQ (at least I dont think so but who the frig knows with this stuff)
Then joist hangers, etc. Building flush beam 10' off the ground is aok with 2 guys or more. I did mine at my house by myself and that was a bit of a bugger. Make sure you have help.
While we are on the subject. For those who have not all ready seen this.
http://www.deckfailure.com/index.html