Basement Framing
 

Quck question,

I am starting to frame a wall (in the basement) but unsure on how far the base plate should be from the wall. Any help?

I generally leave 1" to 1 1/2" --That allows for the out of plumb foundations--

I usually leave 1/2". The basements I finish are generally houses less than 20 years old. Around here if the block is out more than a 1/2", it usually means there is a problem with the foundation.
Mike Hawkins:)

Half inch is plenty, a basement shouldnt be out more than this much.

My basement is insulated with R12 foundation wrap, so I built my walls 3 1/2" from the basement walls.
This takes about 8" away from the size of the room.

Wildie, I count 14" cubic inches from the total area. I vote 1/2" from the walls. :thumbsup:

Take some plumb readings all around the room. Make sure if any of your walls are out that you adjust your measurement so you can carry your gap up with the wall still plumb.

Sucks to start framing and find a wall out of plumb by more than your 1/2".

Also depends on what you plan on doing for insulation.

You have all mentioned "Plum" but what about straight.

Should we not mention the straightness of the wall, or are we going to assume it is straight, you might as well figure where the wall is at its worse for "plum" also run a string line on its length about an inch or so away from wall, to map out where the most abrupt point of the wall(s) are.

Mark

Lets start all over again, as I'm not following you?

Did I make a mention of area somewhere?

You said, I assume your taking about 3 1/2 inches from each wall, 3.5" x 4 walls = 14 square inches

Not to mention each wall is about 4" thick, so you loose approximative 2' 6" from the total area.

Not trying to be a :censored:, its just the OP will want to take this into account when building away from the foundation walls.

Oh, now I understand! I meant to say that it takes away about 8" from each outside wall.
Of course, any framing will encroach into the room space, so in my case I would have lost 4", anyway if I had framed tight to the wall. However, I lost another 4". The net result was 8" per outside wall.

That air gap between the foundation and your framed wall is important. The gap allows air flow and will help if any moisture penetrate thought the foundation. You will never notice 1/2 inch to 2" gap when all is said and done. Plumb is most important, but it doesn't hurt to pull some string lines to make sure the wall is straight. When I finish a basement I build my walls 3/4" short and actually use 3/8" bolt and aluminum plates to jack the bottom plate off the cement floor. This way you have no wood touching cement and allows for air flow which aids in a dry basement. Also using a piece of composite 2x4's for the bottom plate will save it from rotting when you get water in your basement.

Ok, I am ready for how overkill this is and all the naysayer that will comment, but I always go the extra mile. Seems to payoff in the long run.

I used 1X4 PT blocks on 2 foot centers to raise the plate off the floor. For the laminate flooring I used DELTA dimpled underlay underneath to allow airflow under the floor also!
i have also installed 2 bathroom fans, mounted in the walls to pressurize the envelope and to generate air flow behind the walls and under the floor.

If going for a finished basement, don't leave air gaps for convective loops or moisture from the basement air condensing on the colder concrete wall; http://joneakes.com/jons-fixit-database/743

http://www.swinter.com/services/docu...Insulation.pdf

http://www.buildingscience.com/docum...ent-insulation

http://www.buildingscience.com/docum...lation-systems
You want to prevent any basement air from reaching the wall, starting with ADA; http://www.buildingscience.com/docum...wall-approach/

Gary