PVA sealer?

[Ken Fitzgerald]

Folks....I need some advice.

I'm about to start painting my new shop. I installed 4 mil plastic under the sheetrock on the ceiling and 1/2" plywood on the walls. The local building code inspector has advised me to paint the ceiling and walls with a PVA sealer.

1. I worried that this will trap both the sheetrock and plywood between 2 vapor barriers. Doing so might, IMHO, cause any moisture that might reach these materials to be trapped in them resulting a quicker deterioration? What's you opinion and advice?

2. If I decide to use a PVA sealer, how should I apply it?......roll it?.......spray and back roll? If I were to spray and back roll, what kind of a sprayer should I rent?

3. Will the PVA stick to the plywood or should I put a primer on it first?



All opinions welcomed! Thanks in Advance!

[Chris Barton]

Hiya Ken,

Did your inspector say why you should use PVA sealer? If, it is to prevent vapor incursion from outside to in I would be more apt to use a product like Drylock (sp?) which is some sort of latex sealer. I have used it before with great success. However, I am like you, and would not be to anxious to trap my wall finishings between 2 vapor bariers.

Chris

[Larry Reimer]

PVA, Polyvinyl Acetate, was formulated because it's not as toxic or harmful to formulate or use. If memory serves (and mine is old and faulty) it's not an impervious moisture barrier, at least not like your plastic sheet. I believe it would "trap" moisture about like any latex paint. That's usually not a problem.

I would use a roller to apply

Yes, it will stick to your plywood.

[Jason Roehl]

The reason to use PVA sealer on your plywood is not so much for vapor barrier purposes. Unless a waterborne paint is specifically formulated for vapor retardation, it's probably pretty vapor-permeable. I'd bet the inspector recommended the PVA primer because it's a good surface sealer in terms of not letting your topcoat soak in, making it easier to paint on the topcoat (not necessarily easier to cover in terms of color, but your roller will glide nicely). It's just one possiblity, though. You could ask at a paint store what they would recommend for your situation. In general, I wouldn't trust too much finishing advice from home inspectors, as they are usually more versed in structural and mechanical concerns. They typically don't get into the cosmetic aspects of a building (unless there is an underlying issue, such as water infiltration or condensation, etc.).

[Ken Garlock]

Ok, Ok, this is a dumb question :confused:

PVA sealer? Aren't we talking yellow glue that has been thinned down? :) From what I know, yellow glue is not waterproof, if that is the goal.

I would NOT take an inspectors word on anything outside of what to do to pass inspection. :p I would stop by a couple paint stores, not the big boxes, and get their recommendations. After sorting out their need to sell something, you can probably come up with a better answer.

Personally, I would go with good old latex paint, two coats.

[Ken Fitzgerald]

Ken......PVA in this instance stands for polyvinyl acrylic, I believe. It's a latex formuated paint that is supposed to be a vapor barrier. The local building inspector liked it better than plastic. I'm not sure why but that's the recommended first coating over unpainted drywall.

[Cecil Arnold]

Just a guess, but could it be anything like sizing that you put on before wallpaper??

[Ken Garlock]

Ken......PVA in this instance stands for polyvinyl acrylic, I believe. It's a latex formuated paint that is supposed to be a vapor barrier. The local building inspector liked it better that plastic. I'm not sure why but that's the recommended first coating over unpainted drywall.

Thanks, Ken, for the enlightenment :) It must be something that is done up in your neck of the woods. I had never heard of it either in Ohio or in Texas. Like they say, live and learn. :cool:

[Jim Becker]

It's primer...so that your real paint goes on nicely and doesn't soak in like you put it on a sponge. No need to worry about it being a second "vapor barrier"...it will not be.

[Chris Padilla]

Ken,

I would just use a good OIL-BASED primer. All the pro painters I know prefer OIL-BASED primers. Then you can paint anything you like over that. I know, oil-based stinks to work with but....

In my garage, on my drywall, I just used a cheap latex primer from the orange box and then, just because, I used a good EXTERIOR grade acrylic pure white paint. The light in my shop, with white wall, is simply INCREDIBLE!! No shadows in my garage/shop.... :)

[Ken Garlock]

I second Chris regarding the white paint. Get the whitest white you can find and paint the entire shop with it. I think I used "ceiling white", IIRC.

[Ken Fitzgerald]

Chris and Ken......based on that shop lighting article I bought from FWW I will be painting my shop all white. According to the article before age 40 you need 50 lumens after age 40 100 lumens ....as I'm approaching 60 I'll take all I can get ......thus....white ceilings and walls.

[Ellen Benkin]

My recollection is that you put a PVA primer over new sheetrock to seal it so that the first coat of paint doesn't just sink in to it. It does no harm to anything, but serves to save you money in the end.