remodeling question for TX/Austin

[atgcpaul]

My cousin's wife posted pictures on Facebook of a home remodel they are doing in Austin, TX.  They're using a contractor.  Lots of new interior walls, etc.  The bottom plates of the walls sitting on concrete don't look like pressure treated lumber, and she confirmed they looked like "normal" wood, but did add that the builder did a termite treatment followed by a plastic vapor barrier before pouring this new concrete.  I only saw pics of interior walls.

I have framed one wall in my life on concrete and have seen it done a bunch on TV (so I have no real experience), but have always heard that if there is wood on concrete, it should be pressure treated.  Is that just a CYA thing or a regional thing or code or not always necessary depending on the location of the walls, etc?

[fixtureman]

We built hundreds of slab houses and never used treated wood on the bottom plates.  There are also thousands of houses that have basements that have untreated wood for rooms.  Some of those remodel shows do stuff that makes no sense.

[Snipe Hunter]

It's "preferred" but not code everywhere.

In some places like here, it's required in basements but not required for slabs on grade.

[daddo]

Back in the 70's I remember we would put down a strip of felt underneath- for some reason.  

[Snipe Hunter]

Back in the 70's I remember we would put down a strip of felt underneath- for some reason.  

I've seen it set on plastic sheeting and then they wrap the sheet up and staple it to the studs. Not sure I like that either as it creates a "bucket". Not good if the water is coming in from the top, down.

[Large Wooden Badger]

With Habitat we put down a little blue foam strip under the bottom sill.  I think its more for insulation, sealing drafts than water protection.

[chips ahoy]

Around here there is a strip of pink foam,the same width as a 2x4 put down.It is called sill casket,don't know if it is code,but have used it.

Mel

[K. L. McReynolds]

Local codes here require PT lumber for concrete contact. That means on a slab or on a foundation wall. The foam layer (between the board and floor---even with a wood subfloor) is also required.

There is a newer PT treatment(newer than YellaWood) that looks a lot like natural untreated wood, just a wee bit darker. HD has it locally. I just ripped some to make a 2x2 frame and ran out. Used a regular 2x4 as replacement. I'll try to remember to take a photo tomorrow.

[EricU]

I did both pressure treated and the insulation foam.  

It's a good idea, but probably most builders just do things like they always did until code enforcement makes them do it to code, but code enforcement hasn't caught up.  You find that a lot.  For example, on our deck, I paid for the code-required 2" of gravel underneath to keep out critters, but the builder had never heard of such a thing and the code guys didn't require it so the builder skipped it.  I ended up paying someone else to put it in after critters started living under the part that the contractor had skipped.  I just got tired of arguing about stuff and let them leave it bare, which was a mistake. I'm assuming that now, 7 years on, code enforcement requires the gravel.

[K. L. McReynolds]

   

   
In the two pictures, the regular construction lumber is the two top long pieces(light colored). All the rest is PT in the new type from HD. That illustrates how much the new PT lumber looks like regular lumber. It is heavier, even dry.