# Framing interior wall on concrete



## Truth (Jan 5, 2012)

I am building a wall to make two rooms out of my former garage. The floor is concrete. I will be putting down a 6 mm vapor barrier on the floor. Do I need to put that barrier under the pt wood that I will use as my base plate for my wall of which I plan on anchoring to the floor? I also have approximately 1/4 to 3/4 of an inch difference in the level of the concrete over the 20' span where the wall will go? Can this be shimmed and is there such a thing as pt shims? Thanks for advice in advance!


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## joecaption (Nov 30, 2011)

No need for the plastic under the PT.
And no there are no pressure treated shims.
Cedar will work.


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## abracaboom (Dec 27, 2011)

Put your p.t. plate all the way against the concrete (no shims) and cut each stud to length. Or put your p.t. plate against the concrete (no shims) build your wall with two plates and all studs the same length (shortest length) and shim between the two bottom plates. I would never shim between the plate and the concrete.


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## Truth (Jan 5, 2012)

Thank you very much. I'm quite new to this kind of work, I've looked up videos on how to frame out a wall but I have yet to understand if I need a 2x4x20 for the top and bottom plates or if using 2-10' 2x4's is ok. Also is it ok to attach sheetrock to pt wood? I'm a handy lady who has lots of tools and has done many projects but never frame a wall. Sorry if my questions seem so elementary. I'm very grateful for the advice.


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## Truth (Jan 5, 2012)

Thanks Abracaboom! That makes sense. So instead of building the wall on the ground and installing. First install pt plate, then another base plate w shims where necessary. Intall top plate to cross ceiling joists then toenail the studs into top and bottom plates at the proper lengths? That makes great sense to me, am I thinking right?


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## mae-ling (Dec 9, 2011)

I would build the wall with only one bottom plate (the two idea is not wronge just different) then shim and nail at the top. A little faster and easier to plumb

If you are framing on 16" centers use a 16foot and a 8foot and alternate the top from the bottom so joints are not on same stud.

Yes it is fine to attach drywall to PT wood.


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## Truth (Jan 5, 2012)

I just reread what you said. I get it... Sory for the delay in understanding. Is it ok to attach sheetrock to pt?


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## abracaboom (Dec 27, 2011)

Truth said:


> Thanks Abracaboom! That makes sense. So instead of building the wall on the ground and installing. First install pt plate, then another base plate w shims where necessary. Intall top plate to cross ceiling joists then toenail the studs into top and bottom plates at the proper lengths? That makes great sense to me, am I thinking right?


In both cases, the p.t. plate would be bolted to the concrete first.

If you use only one bottom plate, cut each stud to its unique length and toenail.

If you use two bottom plates, build the wall on the ground (with the second bottom plate, top plate, and all studs same length), lift the wall over the p.t. plate, and then shim. This uses one more plate but you don't have to toenail or measure each stud. If you use bolts for the p.t. plate, plan ahead how you are going to deal with the nuts and the second plate.


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## mae-ling (Dec 9, 2011)

You can also use one bottom plate and shim at the top. 3 different ways of achieving the same thing.
It sounds like a non-load bearing wall I would nail it it with concrete nails and a gun (ram set or the like) or use concrete screws. Drill a hole and put in the screws.


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## Truth (Jan 5, 2012)

I was planning on using tapcon concrete screws. I was going to counter sink them.


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## mae-ling (Dec 9, 2011)

Sounds good. No need to over countersink them,just pull the plate down tight.


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## abracaboom (Dec 27, 2011)

Truth said:


> [. . .] I have yet to understand if I need a 2x4x20 for the top and bottom plates or if using 2-10' 2x4's is ok.


If you use two bottom plates:

The p.t. plate can be 2 pieces 10' long each.

To go over this p.t. plate, you can build two walls on the ground, each just over 9' long (16 gap between the two walls when they are up). Then you would not need help to raise them.


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## Truth (Jan 5, 2012)

I actually want this wall to bear some of the load just to avoid any possible sagging due to the weight of sheetrock. Garage has been standing for 30 years and I attached 1x8" ledger board vertically to the ceiling joist and rafter 4' from center. This still leaves an 8' foot span and I would like to store some items in the attic and wanted the wall to divide the room in between the largest span.


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## abracaboom (Dec 27, 2011)

Truth said:


> I actually want this wall to bear some of the load just to avoid any possible sagging due to the weight of sheetrock. Garage has been standing for 30 years and I attached 1x8" ledger board vertically to the ceiling joist and rafter 4' from center. This still leaves an 8' foot span and I would like to store some items in the attic and wanted the wall to divide the room in between the largest span.


Ledgers are always horizontal, I think you mean side posts. Having the plates (or the walls) be in one or two pieces will make no difference as far as how much weight you can store in the attic. If you put A LOT of weight up there, what might happen is that your concrete slab cracks, but I don't think that's your plan.


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## mae-ling (Dec 9, 2011)

If this wall is truely load bearing then it is another matter.
What is the distance between this wall and the other wall?


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## Truth (Jan 5, 2012)

Sorry about that, the man at the lumber yard called it ledger board. You're right I vertically attached 4' 1"x8" boards. I only plan on a few holiday items, not heavy stuff.


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## abracaboom (Dec 27, 2011)

Truth said:


> Sorry about that, the man at the lumber yard called it ledger board. You're right I vertically attached 4' 1"x8" boards. I only plan on a few holiday items, not heavy stuff.


He meant that those boards are mostly sold to be used as ledgers. 

(No need to apologize for things like that.)


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## Truth (Jan 5, 2012)

This is a 19 x 20' garage. The wall will be dividing the 19' span. However with the vertical posts attached to the rafters and ceiling joists the span between the posts is 8'. Although one of my builder friends said it would be fine my other carpenter friend said it will be fine if I don't put anything upstairs. I want two rooms nd I want this wall to perform double duty by ensuring it won't sag.


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## abracaboom (Dec 27, 2011)

Those posts in the attic will cut the span of the rafters (if the joists can take the extra load), but won't do much as far as cutting the span of the joists. One key piece of information you haven't provided is the size of the joists, but if you are going to use the attic just for light storage, you don't need to worry about their size.


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## Truth (Jan 5, 2012)

Rafters and joists are 2 x 6 - 24 oc


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## Truth (Jan 5, 2012)

Thank you everyone... I appreciate all the input and advice!


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## Gary in WA (Mar 11, 2009)

Add the plastic under the plate unless you are sure there is one present between the slab/earth: http://www.greenbuildingadvisor.com...ressure-treated-sill-plates-and-building-code

Gary


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## mae-ling (Dec 9, 2011)

If you want to get really technical attach you bottom plate centred between the studs, not near a stud. So if moisture comes up the area of the screw it is not near the untreated stud.


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## Truth (Jan 5, 2012)

Great link and advice GBR... Thank you. I did install a portion of the wall already and code did not require me to have the plastic underneath... However the remaining 10 feet of wall will have plastic under the pt plate bc I'm not sure if this garage has plastic between earth and concrete. Is there something I can brush or spray on the bottom of the installed studs in the event wicking may occur (FYI...previous owner had a beam that according to engineer was doing nothing supported by kd 2x4 and I've been here for 4 years and the regular upright 2x4 lame wood post has no rot of any sort)


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## Gary in WA (Mar 11, 2009)

You can try a water-proofing liquid, like a deck treatment, though I don't know how well that will work now. You may not have a problem, or possibly will...... Nice answer? Depends on the site conditions; drainage around the slab, underground water sources, capillary action, etc. If the wall framing will remain open, the moving air currents should keep it all dry.

Extreme is caulking the wedge-anchor holes before installing the fasteners, been there, done that. Lol

Gary


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## Truth (Jan 5, 2012)

Wall is complete and it's plumb :thumbup:I also have a 1' tall concrete wall around the perimeter of the garage which is 10" thick. On top of that sits 2x4 studded walls that are 8' tall. I've been given much advise on how to handle this, however much of the advice is conflicting. I am thinking the best solution is to put 6mil vapor barrier over concrete portion and use construction adhesive to seal it where the concrete wall meets the plate of the wood wall. Then install pt wood studs to the concrete (w vapor barrier in between) and extend up 4 and adding horizontal supports as well creating an aesthically pleasing shelf around the perimeter of the room. Then foam board insulation against the barrier that's against the concrete portion inbetween the studs and add drywall...any thoughts as I greatly appreciate your wisdom!


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## Gary in WA (Mar 11, 2009)

So what is the end use of these two rooms, will they be conditioned?

Gary


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## Truth (Jan 5, 2012)

Yes. Heating and cooling vents already installed (forced hot air). Basically bedrooms (possibly office).


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