No. Not inherently.

It's worth doing a pressure or leak test on something you're uncertain of, but it's not likely to be an issue.

I'm sorry, furnace filter? I'm 99.9% sure those don't exist here in the Netherlands. Is this for people using forced air heating like a savage from the 60's?

cheese

Just construction adhesive that won't eat foam... Loctite pl300 is what I used. Use it to glue the board to the rim... You can use roofing nails or something weighty to hold the board to the rim while the glue sets.

What’s the foam adhesive you mentioned? You describe it I think as holding the foam board in place?

Viewed a really nice house about 2 yrs ago at easily 40% discount. Reason someone had used this around one are of the house, resulting in moisture and wood. Rot. Mortgage companies wouldn’t touch the house. Cash sale only.

I'm much cheaper than that... I did 2" foam board and then those kind of cans to seal around them.

Foam board was cut into pieces roughly and inch shy of the cavity dimensions... E.g. 14*5 for a 15x6" opening. Once the foam adhesive set (e.g. following weekend) I sprayed around the edges to seal it in.

I had to get a 30" gun adapter to do it which requires cans that can be attached to a gun. The ones that can't may not have the reach to get you into the cavity.

If you have full access to the cavity, that dap kit someone else sent would be my go-to... I didn't have the immediate access or will to do it all in one go... There were unmentioned complications in my way requiring lots of prep work.

E: Code likely requires a fire block between the living space and the foam. Afaik drywall, rockwool, among others count.

Even pros fuck houses up with spray foam. It can trap moisture and lead to massive problems with rot and mold.

But will keep your Silverado on the road for an extra 5 months.

Well it's a hell of an enema

Hmmm, I see the logic of warm side cold side and condensation. I just can't get my head around the idea of creating a type of vapor barrier and potentially sealing moisture between the joists and outside plate like that.

Not saying you're wrong, just thinking out loud. Thank you for your input!

You'll probably want the batts in first before the poly to get the vapour barrier on the warm side, but yeah spray foam isn't cheap so it's best used for spots you can't insulate conventionally.

There's the added benefit of making future work easier if you don't need to chip out a bunch of foam to run a new wire for example.

In they didn't finish the story. They ate the neighbors immediately after.

Thanks.

Yeah we're on the edge of zone 5/6, so fairly cold in the winter, we do more heating than cooling, and a high r value is desirable.

I did some research after posting my question, and it seems like a cheap way to get sealed and high r value is to do what you said and cut poly to fit, and then seal the edges with spray foam. But then instead of doing more layers of that, just put a few inches of unfaced batting on top to boost the r value. I'll probably go that route, do the whole basement for $50-75 instead of $500.

As long as there's something acting as a vapour barrier you'll avoid condensation, it doesn't need to be spray foam. You want vapour barrier in the warm third (by R value, not necessarily thickness) of the wall to avoid condensation. So hot places that mostly run AC will have their vapour barrier to the outside off the wall, where cooler places you tend to heat is the opposite.

You can do the joist ends with batts and poly, it's just really hard to get a good seal especially with I-joists. I think the foam stuff is R5 per inch? Might be a bit better than that but was targeting R20 so 4" inches thick, maybe a bit thinner if it's R7 per inch. R value is a measure of how well something resists heat transfer btw, higher number is better.

Check how things are built in your area as it can be very regional depending on climate and building codes.

Just some clothes and hot air - lint will come running!

How thick did you go for that? I need to do that before winter.

Cheaper alternatives?

My understanding is that it's best to use spray foam here because it's an outside surface you're insulating from inside, so moisture will condense there unless you seal it.

Do you have to prime your lint trap? What does lint like?

Good job on not taking the easy way out and just poisoning them

Sprayed insulation: when you want to make future work a complete fucking nightmare. Also great for hiding damage which will be even more difficult to repair later.

... in retrospect I should have phrased that better.

I had a noisy neighbor situation in a condo some years back so I rebuilt the wall we shared for maximum sound isolation. I achieved an (estimated) STC of like 70+. Offset studs, resilient channels, sound dampening panel with bilayer 5/8ths drywall with acoustic glue + acoustic sealant. I never heard anything again.

This comment would fit right at home in Jeffrey Dahmer's post history.

https://www.homedepot.com/p/DAP-TNFP-System-200-Kit-Low-GWP-Spray-Foam-Sealant-Insulation-62620/315138555

Something like this maybe? I've used a two-part system like this before to insulate/vapour barrier between the joists where they meet the foundation wall and it worked decently for that.

If you're doing the whole ceiling though I'd go for batts of some kind or hire a spray foam company.

Yes. Worked well but burns through cans. So overestimate for your project or look for industrial size application canisters if a larger project. No idea where. And would recommend a tyvek suit and a good face mask. Also difficult to get a desired thickness if R value is important

What is it for?