Pressure treated for base plate framing on concrete

I've always been told that the sole plate must be pressure treated, when in contact with concrete. I found section 317.1 in the IRC, but it only seems to address "sills and sleepers". It also states that the members only have to be PT, if not separated "from the slab by an impervious moisture barrier.".

Based on the code I've found, I'd say there's no requirement for the sole plate to be PT. Even if it was shoehorned into this section, putting an impervious moisture barrier between the sole plate and the concrete would meet the requirement.

I used untreated wood and installed sill gasket under the walls, when I added framing to my basement. Though it was just a couple dividing walls, so it was never inspected.

Chapter 3 Building and Planning

Section R317 Protection of Wood and Wood Based Products Against Decay

R317.1 Location required. Protection of wood and wood based products from decay shall be provided in the following locations...

How does it go, you can pay me now, or you can pay me later.

Most municipalities can provide you with a "cut sheet" of acceptable building practices, as a handout.

However, to address a solution to the problem. If your walls are continiously blocked, remove these. At the sole plate, cut a shallow "V" underneath all the studs,(its faster than pulling all the nails), cutting the nails.Remove the old sole plate, cut off the anchors.

Install the new treated material, rebuild your wall, set in place and anchor according to the requirement for your area.

As I understand, you are building this WITH-IN an enclosed area and that this is not an exterior or otherwise structural wall.
In that case, there are a number of fastening methods which may be employed, of which, via a powder activated fastener, is one.

The following link is to the evolution of pressure treated lumber;
http://www.usatoday.com/news/nation/...d-lumber_x.htm

And...

Code requirements for wood-concrete contact treat the symptoms of rot, not the cause

Last week we talked about moisture meters, and I asked readers why the wood in the picture was wet. As it turns out, that photo was taken in the same house on the same day as the two pictures at right.

Why is one bottom plate sitting on concrete “dry,” and the other one “wet?” I admit that this week's top photo was taken in the basement and last week's and the bottom photo were taken in the crawl space, but the location is not the cause of the different moisture readings. The reason is simple: sill sealer. The light blue sill sealer installed between the bottom plate and concrete (most likely for air sealing) in the top photo is closed-cell foam. It's meant to be an air-sealing gasket, but it also is working as a capillaryForces that lift water or pull it through porous materials, such as concrete. The tendency of a material to wick water due to the surface tension of the water...

Sole plates, or sill plates, are the first pieces of framing lumber placed in home construction. These plates must be made of pressure treated lumber since concrete has a tendency to wick moisture from the ground. Anyplace where wood meets the ground or concrete, the lumber must be pressure treated. For additional moisture protection, a gasket or strip of closed-cell foam can be installed between the concrete foundation and the sill plate. Some moisture barriers for this application combine a foam strip with a waterproofing membrane that covers the bottom of the plate as well as the joint between the foundation and the exterior of the wall assembly.

Lay a continuous layer of 1/4-inch foam gasket or similar moisture and air barrier on top of the concrete slab before applying sill plates. The gasket must be designed specifically for use with sill plates; these are commonly sold in rolls. Look for a gasket in the same width as the sill plate you will install. Make sure you...

some more research / notes for the record

Pentachlorophenol treated wood should not be used in residential, industrial or commercial building interiors, except in laminated beams or building components that contact the ground and are subject to decay or insect infestation. When used for such purposes, pentachlorophenol treated wood must be covered with two coats of an appropriate sealer such as urethane, shellac, latex epoxy enamel or varnish.

http://www.uri.edu/ce/factsheets/sheets/chemwood.html

On December 31, 2003, the wood treatment industry stopped treating residential lumber with Arsenic and Chromium (Chromated Copper Arsenate, CCA). This was a voluntary agreement with the United States Environmental Protection Agency. CCA was replaced by Copper based pesticides, with exceptions for certain industrial uses.[2] Industrial wood preservation chemicals are generally not available directly to the public and may require special approval to import or purchase...