Plastic sheeting to block VOCs from Kills2 primer? Chemists? Anyone?

November 14, 2017 2:02 PM

In case the layer of Killz2 primer I put on the plywood subfloor is the thing causing my headaches/nausea, is there a _type_ of plastic sheet or other barrier that will seal it well?

I've been trying to learn about VOC barriers. One article said that HDPE would eventually just transmit most problematic chemicals, and PVC has its own VOC issues. Is it possible that I could just buy some thick plastic sheeting of _some_ kind, put it down over the subfloor, and then put flooring over that, thereby solving the current "my home gives me unbearable headaches" problem?

Note: I've already removed the laminate floor (which was name-brand, not the stuff from China reported to off-gas excess formaldehyde).

Have considered sanding the subfloor, but there are so many staples/nails it doesn't seem a good option. I've had long conversations with the technical support resource at Behr paint (maker of Killz and Killz2), but they are no help with this. I've sent them a sample of the batch I used, but I wouldn't be that surprised if it is completely normal.

This layer of primer (Kills2, a water-based primer) may not be the real or the only problem, but it's what I'm addressing now. The area smells strongly of it. It has been more than the 30 days of the official "cure" time, but nobody can tell me when/if it will stop off-gassing _whatever_ it's made of.

posted by amtho to Home & Garden (4 answers total)

I haven't dealt with your specific problem, but I bought a camper that had a horrible off gassing problem that was making me sick. I coated all the surfaces (plywood floor, vinyl-wallpaper-covered foam walls) with a product from AFM Safecoat and the problem was completely eliminated. Like, COMPLETELY. I don't remember which product specifically but it doesn't matter because they have lots of them for specific applications and can make a recommendation for yours.
posted by HotToddy at 2:32 PM on November 14, 2017

"More than the 30 days..."

It's off gassed as much as it's going to. Adding plastic to this equation isn't going to do anything. But you should be putting some padding down, as recommended by the flooring manufacturer.
posted by humboldt32 at 3:37 PM on November 14, 2017

Response by poster: "cure" time, according to Behr Paint / Killz technical support, just means all water has evaporated. Other substances can still enter the air. That's why you can still smell latex paint, or a new car, even when all substances are fully cured.

Not to worry. The flooring installers we're using are putting appropriate stuff under the reclaimed wood flooring we've got. It seems to be some kind of paper, though.

Thanks for the pointer, HotToddy! That looks very promising.
posted by amtho at 4:43 PM on November 14, 2017

Faced with a similar situation, I put down a layer of 20mil LDPE from a 5' wide roll, and taped it at the edges and joints with a low VOC aluminum tape (made by Polyken, but unfortunately no longer manufactured; EL Foust sells aluminum tapes, but be sure you buy the low VOC one -- and check out their room sized air purifiers), and I'm confident nothing got through it, although the top layer, 76" X 42" X 1/4" sheets of glass, did not pierce the plastic layer at all.

A friend of mine painted a water damaged wall with Killz, by the way, and I was never able to spend more than 20 minutes in their house again after that.
posted by jamjam at 5:19 PM on November 14, 2017