Is using a Kilz primer on an interior earthen plaster wall environmentally friendly? If not, is there a way to seal it and make it safe?
I'm painting an interior wall on a friend's home, and she wants it to be as environmentally green as possible. I primed her earthen plaster wall with Kilz, assuming that no odor meant no VOCs. Oops! Apparently Kilz is not "green," so now I'd like to remedy the situation, by somehow neutralizing the Kilz or sealing it from the interior room, before applying the topcoat (Sherwin Williams Harmony paint).
My answer here actually starts with a question: what is the substrate behind the earthen plaster?
The reason I ask this first is because if these are strawbale walls it would be prudent not to seal them, as they actually need air transfer to be able to "breathe." If strawbale walls are air sealed, then the possibility of mold, mildew, and eventually catastrophic failure of the wall becomes much greater.
Now, if the substrate is not straw or some other substance that needs to breathe, and if this is a material that can be sealed, i.e. sheetrock, plywood, etc, then you have some options here.
- The first option I would offer, possibly for future applications, is that Kilz now offers a no-VOC primer that performs similarly to its VOC counterpart. I used this product in a recent remodel and felt good about its performance.
- Another option, relating to neutralizing the VOC content in the Kilz, would be to use another coat of clay-based paint or plaster over the primer. Clay is renowned for its cleansing and neutralizing properties and has been used for millennia as a building material and health supplement.
- Finally, if the topcoat is latex-based, a proper and thorough application of the paint will provide a seal to keep any additional VOCs from entering the living space. In looking at the data sheet for the Harmony paint you speak of, I see that it is in fact latex-based.
So if the substrate behind the earthen plaster wall does not need to breathe, your easiest and quickest option would be to simply apply a topcoat of the green paint that you already have over the primer.
And next time you will know that a no-VOC primer is available!
For more information:
Read Bill Fry's Q&A "Is the no-VOC paint Freshaire Choice a good pick for painting my son's room?"