Taping seams in plywood for health reasons?
dominic123
| Posted in Green Building Techniques on
Climate 4C. I am debating the cost and effort of taping our plywood sheathing.
Due to a few circumstances, we changed our building wrap to doubled-up 60-minute paper, attached to furring strips (closed rainscreen). Alternatively we are considering a hybrid product called Hydro-Tex, which is tar paper that has a drainage plane on the backside.
Either way, is there a risk of this petroleum based product causing health problems, which the inhaling of off-gassing? I know most people who tape plywood seams do so for energy reasons, but is it reasonable to do so more for health reasons?
Thanks.
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Replies
It's on the exterior side of the assembly, and you should be making the interior side air tight too. The amount of off gassing from the adhesive that could actually reach the interior is theoretically miniscule, if both the plywood and interior wall sheathing are air tight, and the tape is on the exterior.
Thank you Dana. I was actually thinking about offgassing from the tar paper. I trust the Siga tape is a good product; I don't trust the tar paper. Is my concern unwarranted? Thanks again.
I am very particular about interior air quality. But I would not be concerned about the tar paper if the seams are taped on the plywood. It is much more important to minimize VOCs inside the structure and to have a good plan for ventilation.
Thank you Steve and Dana.
Mike,
You need a good air barrier for a variety of reasons. Whether this is the taped plywood, poly, some other membrane, or the drywall, is largely unimportant. Done diligently all of them will preclude any off-gassing of exterior materials from affecting you in the house.
Mike,
You've gotten good advice here. I'll just reiterate an important point: Although you don't have to tape your plywood seams for health reasons, it always makes sense to tape your sheathing seams in order to reduce air leakage.
Remember, this is the only chance you'll get to tape the seams. Once your siding is up, it's too late.
-- Martin Holladay