I asked this question over at house chat but thought I’d post it here as well. I’m just getting started on a major remodel of an old farmhouse that originally had wood siding and little if any insultaion in the exterior walls. Over the years cellulose has been dropped into most of the exterior walls and vinyl siding added to the exterior. I think the only thing between the old wood siding and the vinyl is house wrap but I haven’t verified that yet. During the remodel almost all of the interior plaster walls will be removed and I plan on reinsulating with blown in cellulose or fiberglass. I live near the Mason-Dixon line so winters are cold but not arctic and summers are hot and very humid.
I don’t plan on installing polyethylene between the drywall and the insulation. Good choice or bad?
It seems to me that the old wood siding will act like a sponge during the summer (A/C on inside) and soak up any condensation on the back of the house wrap. Am I right? What could I do about this?
Any other comments/suggestions are appreciated.
Replies
It doesn't seem like you're thinking about the moisture in the right way. Moisture moves from wet to dry, and from warm to cold. In the summer in your climate, the moisture drive is therefore likely to be inward. I doubt that you'll have trouble with the siding holding moisture, but if you add an interior vapor barrier, you can create a condition that prevents summer water in the walls from drying the way physics intends - to the inside.
Andy
Never try to teach a pig to sing. It wastes your time and annoys the pig.
Thanks, that makes sense. I guess then the most important part is to make sure that there is no vapor barrier on the inside.
Exactly. And remember, some paints are vapor barriers, and vinyl wallpaper most definitely is.Andy
Never try to teach a pig to sing. It wastes your time and annoys the pig.