On 17 May 2006 09:04:59 -0700, "Woodchuck34"
wrote:

We just bought a new house, almost the day after I finished my current
basement. Go figure. I'm a regular on rec.woodworking, but thought
this question would be better applied here.

We had a local engineer do our house inspection and he has an excellent
reputation. He outlined the best way for us to finish the basement.
First, a little background. Its poured concrete, built in '92, and
doesn't appear to have any leaks, doesn't even have a sump pump, but I
want to make sure I don't have any moldy or musty smells after I
finished.

This engineer recommend that we glue a 6 mill vapor barrier 8" below
the sill plate on the walls, keep the stud frame 2" off the walls, and
bring that barrier down and around the floor plate on the new stud
walls. Also recommend using some sort of waterproofing sealer/paint.

First, has anyone ever heard of glueing the barrier directly onto the
wall?

Second, what is the best sealer to use?

I live in PA for climate reference.

Any help or suggestions would be much appreciated. I'll paste the
relevent parts of the report below.

Thanks,

Chuck

For your reference we are providing the following general information
regarding finishing the basement into living space.

First seal the interior of the basement foundation walls and floor with
a good quality waterproofing material. Both surfaces should receive at
least two coats of the sealant. Deco, UGL Drylock and Glidden make
commercially available products for this purpose. There are also other
available products as well as some commercial grade products available
through certified installers that should be considered.

Following this, a 6-mill or thicker polyethylene vapor barrier should
be attached to the top of the foundation wall approximately 8 inches
below the sill plate. This polyethylene should be glued and bonded to
the foundation wall with appropriate adhesive. It is important to
obtain a good seal in this regard to prevent moisture from migrating
upward to the wood sill plate around the perimeter of the foundation.
The lower end of the vapor barrier should be placed under a new
2"x4" wood stud wall used to frame the finished basement area.
Provision should be made to ventilate this space and allow any
condensation that may develop to escape. The new stud wall should be
attached to the first floor framing and the basement floor and should
be located approximately 2" off the interior of the basement
foundation wall. The vapor barrier should be as continuous as possible
to prevent moisture from migrating into the wall or first floor framing
above. The 2" spacing from the foundation wall will allow air to
circulate in this area and reduce moisture levels. The interior frame
walls can then be insulated and finished with drywall and/or paneling
as is typically done. A dehumidifier or two should be used as needed.

If you actually have water coming through, you need to fix that from
the outside; whatever is required.

If you just have water vapor diffusing through the wall, then the
interior dampproofing can be very effective. I've had excellent
results with the oil based Drylock. It smells horrible when you are
applying it, but it does work well. The latex formula isn't nearly as
effective.

Here's what I've done and it's worked well for me. After living
through a rainy season to make sure there are no actual water leaks
through the wall, I caulk the seam between the walls and slab with
polyurethane caulk. Then I applied the oil-based drylock to the
walls. Two coats, with a brush. You really can't roll the stuff on
effectively, although you can roll it on and then brush it in. It has
to fill all the pores in the block to be effective. Let it dry for a
week or so, until the odor is completely gone.

Then I glue two inch foam insulation board to the wall, using the
proper foam compatible construction adhesive. You need the solid cell
foam that doesn't absorb water, and the type with borate treament to
eliminate any chance of mold or insects is best. All the foam seams
are taped with the type of long-lived tape used for house-wrap or
equivilent. The object here is to form a very good vapor barrier so
warm moist air from the inside doesn't reach the cold wall and
condense. Tape the foam to the floor as well.

Then I build a 2 by wall 2" or so out from foam. It doesn't need to
be insulated because of the foam, which makes it much easier for
running utilities, etc.

This is not a cheap project, the drylock and foam are pricey. But it
really works well, as long as you don't have any seepage anywhere
through the wall before you start.

As always, clear all this with your building department. You may get
stuck providing a means of secondary egress before they let you finish
the walls at all.

YMMV. Good luck with your basement.

Paul