Vapour Barrier Paint?

olyteddy

I've used BIN as a sealer and in extreme cases have used UGL Lock, even though it's primarily for concrete.

NAV

UGL Drylock has sand in it.....how did that look on drywall?

Burby

I be thinking Dan may be so correct in his reply.
I read about you wanting a vapor barrier paint & posted who I would trust if in need of such. Would perm rating of 1 not be more than a perm rating of 0.4 ?
Regardless of that after reading your quote in Dan's post stating,
Originally Posted by big builder
We are trying to avoid stripping all the drywall down on this reno we are doing...... there is plastic barrier behind the drywall but it must have many leaks.

We have seen condensation and frost behind the insulation andin places in the attic.

I was thinking that since everything is drywalled , that if we could seal the paint, trim, and caulk everything it should help.

Assuming the poly behind the drywall must have many leaks, I would think would be the wrong way to assume.
You do want walls to breath while at the same time not allowing inside warm air out thru the walls. The poly is preventing inside warm air out.
This was a practice the utility companies were recommending for good cents homes, poly behind the drywall. As long as the insulation is unfaced insulation.
If all has drywall where other than the attic are you sure there is frost & condensation behind the insulation. And in the attic what type of insulation is used? If foil or paper faced, which way is the barrier applied, down or up?
With the amount of years of building / remodeling in Maine & NH and yeah there be some serious cold there, I believe the problem is something no paint is ever going to resolve.
Check a few more things before you put to much into paint materials & labor. Just to be sure.

Merry Christmas

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olyteddy

Touched up with texture and topcoat, just fine. I only ran it about 8" up the wall after sealing the floor with it. There's also a Behr 'Basement and Masonary' paint that doesn't have grit.

RandallS1

Hi All,

As a professional commercial painter specialzing in commercial work I have sprayed a lot of coatings through high pressure airless equipment. Averaging around 25 gallons per day, per gun. Home Depot sells Behr Premium Plus Oil-Based Primer & Sealer. On the back of the can at the top of the instructions for use, under the heading "Where to Use" the following is stated: As a vapor barrier, this product has a perm rating of less than (1.0). Apply two coats." It may not have a perm rating as good as BIN, but anything below 1.0 is going to do the job with repsect to retarding the passage of water vapor. I doubt that it is going to be 100% effective. If you need that kiind of performance you might want to look at 8 mil polyethelene. Be prepard for condensation on the back side if you use that stuff.

The Behr Primer-Sealer does work and it can be rolled, brushed and sprayed. All work well. It drys smooth. Let the first coat dry overnight. Recoat. Two coats is a good vapor barrier. If sprayed with an airless sprayer use a .015" tip. Takes a while to dry, cleans up with mineral spirtis or paint thinnner which is mineral spirits with a different name, and has lots of fumes. If spraying, it's best to wear a mask, not a simple dust mask, but one that uses disposable organic vapor cartridges. They usually have activated charcoal in them and a dust filter over the top. They work and so does the Behr.
Hope that helps.

big builder

Just got back to reading more posts.

Danahy, I don't know that I would be trapping anything between the paint and the 6 mil.

The problem is more where the cathedrals turn into the small attic area and the back side of the wall sheeting ( behind the insulation) in certain areas on the floor.

It's a complicated house that has so many small area and dead spaces that I think the vapour barrier was just extremely difficult to put up properly.

Attic fans have really helped. I think the paint will also help slow the moisture too. It's a neat experiment.

Also remember we are here in mid Ontario where we see days of -20 for extended periods. Really makes condesation a reality.

nEighter

http://www.duspec.com/DuSpec2/produc...Type=datasheet

tookalook

Key words were plastic behind drywall. that's a vapor lock it would probably explain the frost in the attic. Plastic vapor barrier has been a thing of the past four many years. Vapor barrier must go to the outside of the heat source. You do have a prob and probably mold. I hope its not black. Check the roof barrier and roof /soffit vents. aprx 1sq. ft. vent for every 300 q ft. attic.

nEighter

Ctree

Ames makes a VAPORBARRIER PAINT. A premium rubberized elastomeric
coating for waterproofing walls.

Vapor-Barrier is a premium waterborne liquid rubber coating for waterproofing walls. It is for interior and exterior walls, both above and below grade and it stops leaks fast!
It is at amesresearchcom. Haven't used it yet, but I am trying to find it locally for an upcoming interior paint job where the homeowner will be installing blown-in cellulose insulation in the walls and needs a V-barrier on the interior (since the insul will not have it's own barrier). Food for thought.