took me quite some time to realize my place was horribly insulated *on purpose* because that lets the walls dry out. obvious in retrospect but it doesn't feel like conventional wisdom
Comments
Log in with your Bluesky account to leave a comment
I live in an old half-timbered house and insulation was one of the most convoluted parts of restoring it for that reason (we went with interior wood-fiber panels covered with clay plaster so as to allow for diffusion and protect the wood while keeping it visible on the outside)
Well ideally there should be a barrier that is air and water (but not water vapor!) tight between the wall and the outside. That way the walls can "breathe" while air exchange is controlled and can be centralized to recover heat from the exhaust air
yeah, that's what I'm hearing. best solution for my place would be permeable WRB over the sheathing, and then as much rigid rockwool as you can installed outboard, continuously, then new siding. alas that would lose me a lot of money doing that
like in Britain a lot of folks filled their roofs with spray foam insulation without a proper moisture treatment and ended up with rotten decking and rafters https://www.bbc.com/news/articles/cqjrpv218r0o
yeah exactly, even a lot of builders don't get it. you can't just insulate willy nilly or your wall will be running with water. apparently the smart method is sheathing -> peel & stick vapor permeable water barrier -> then rigid insulation *outside*. that keeps the wall assembly conditioned and dry
Yes but also very dependent on your climate and general humidity levels throughout the year - biggest thing is to allow water to wick and be shed to the outside! So, also use a rain screen!
Best methods really depend on specific climate and overall insulation/air sealing goals. It can really vary based on humidity, temp, specifics of your home, and climate.
Signed a person with an older “breathing” home chasing dry rot issues in the roof sheathing.
For example, in warm humid climates, indoor cooling can cause the same condensing surface issues, but on the inside surfaces, if you have warm humid air from outside entering the wall cavity, regardless of exterior insulation, that’s not really a consideration for cold climates.
Yeah, this is essentially like Zip System for new builds. There are options to buy that with insulation of varying thicknesses on the backside of the OSB.
Had a guy straight up come into my (1910) home and suggest blowing foam into the attic and sealing up everything etc etc and clearly had no idea. At the cost of like 25K+ of course
I woke up 10 months after having our attic insulated realizing there wasn't enough ventilation in the attic and proceeded to learn how the fuck you're supposed to add more ventilation; bought a drill and a hole punch. Was not fun drilling through 70 year old plywood.
I think the lead testing person we had come out when we purchased our house mentioned that mold is a big problem in newer construction because they retain so much moisture.
my building is ludicrously insulated—the ambient heat of the building keeps the temp in my unit above 70°F in the dead of winter with my unit's heat off—but also dry enough that it's noticeable and mildly dehydrating, and I'm genuinely curious how they do it
old houses are designed to get wet and dry out. Just let them. Turn the heat down and put a sweater on to save energy or buy a new energy efficient house.
Luckily, you can leave a trickle running at the point furthest from the water heater to help with that.
At least, that's what my grandpa does in his house that's older than our state.
It varies widely; we have EPA Radon Zones by county that show your predicted indoor conc. Granitic parent rock in the Rockies, for example, gets carried and deposited by rivers as fluvium east and west. These granitic rocks have uraninite/radioactive minerals which off gas radon among others
yes. all these old, old barns with ancient clapboards here in my rural part of north alabama get soaked by torrential rain year after year. but they dry from the outside *and the inside* at the same time. so they resist rot.
Comments
https://m.youtube.com/watch?v=uhbDfi7Ee7k&pp=ygUedGVjaG5vbG9neSBjb25uZWN0aW9ucyBhd25pbmdz
Signed a person with an older “breathing” home chasing dry rot issues in the roof sheathing.
That approach also addresses thermal bridging.
It was a good idea, environmentally friendly and saves you money, but unfortunately a lot of people got it done by shysters.
Now the banks have no idea who did it properly or not, and will not authorise mortgages on them.
His advice. Always word of mouth recommendations, don’t trust internet reviews or any of that bollocks.
Funnily enough there’s a pub near us which is owned by a builder, you can ask the barman, he’ll point you right.
At least, that's what my grandpa does in his house that's older than our state.
In England the high radon levels tend to be not where you generally build houses, like hilly, or what passes for mountainous areas, here.