Drop Ceiling Insulation Pros, Cons, and Options...

Just as the title says. My stove is in a finished basement. I know the walls are insulated, to what rating I'm not sure. The drop ceiling however is not insulated. What are some options for insulation here? I believe I have cold air coming through the ceiling from the attached walkout garage.

Would rockwool across the stove room ceiling tiles work? Are there better options?

The long term plan is to someday ditch the drop ceiling for drywall but that won't be happening any time soon. Until then I have to plug up any cold air leaks...

Thoughts??

 

Can you insulate the floor joists above the ceiling? My basement has Sheetrock on the ceiling which is nice but a p.i.a. When a pipe leaks or you want to add wires.

 

My house is a double wide sitting on a poured wall foundation. I believe there is some insulation underneath the house. With that said, I get the impression that the some of the heat from the stove is leaking above the ceiling tiles and getting stuck there instead of going up the basement steps. I am for sure going to have to insulate around the ceiling where the garage attaches. It is mostly blocked off but there are some air leaks I found with the IR gun.

 

Rock wool will work, hard to make a continuous insulated blanket with a drop ceiling. Wire ties mess it up. FYI some drop ceiling have r value of 3.

Before you do sheetrock look up ironpony threads where he uses solid soffit! Brilliant easy to clean, finish etc etc

 

Insulate around the outer wall only (IMO)... the sill plate area. Get a couple sheets of 3/4 or 1" rigid foam insulation board, cut loose fitting panels to go above the sill plate, between the joists. Then seal the gap around the foam panels with some expanding spray foam. Also seal where the sill plate meets the concrete or block wall with spray foam. This will seal up any air intrusion and help insulate a lot. It takes a little time, but not too bad, and the return on your investment is good...to me this is an obvious "low hanging fruit" type of DIY insulation/air seal project...knock it out first...then see what needs attention from there.
The warm air that gets above the ceiling tiles just helps keep your floors warmer...which will help heat the house too. If I had the spare cash to install a wood fired boiler system, I'd have radiant heat under my floors so fast it'd make your head spin!

I like Johns Manville polyiso faced panels for doing this...
https://www.menards.com/main/buildi...-insulation-4-x-8/w-n5100/p-1444438920507.htm

 

If you are living in the space why would you insulate that space any more than you would the space between a second and first floor ?

Find where your envelope is compromised with the garage and repair the envelope.

 

After doing some reading this morning this will be my first project. I will have to take some tiles out to check and see what is currently there.

Now for the next question...would it be better to use polyisocyanurate with an r value of 13.1 or XPS foamular with an r value of 10? Home depot has both I'm just trying to figure out which one would be best for resisting moisture due to being a basement install.

Also are those r values high enough or should I layer it for a higher r value?

 

My thinking was if I insulate the drop ceiling heat would flow across the ceiling and up the stairs instead of getting lost in the space between the tiles and the house floor. I'm starting to think that wouldn't work as planned.

So if I'm getting air leaking from the garage can I stuff those leaks with rock wool until I can button up the garage or would this cause a problem with moisture? The garage is on the long term project list.

 

I did this a year or 2 ago and I can confirm it is well worth the investment/time. It can be a PIA in spots where there may be plumbing etc., but just get the foam board in there the best you can even if you have to piece it in spots and seal it up.

I used something similar to this.

Super TUFF-R 2 in. x 4 ft. x 8 ft. R-13 Insulating Sheathing-99060464 - The Home Depot

 

You could use 2" thick if you want...the R value it has, coupled with the air sealing (that's the big thing right there) will be a huge improvement over what is likely there now (probably nothing) (its not uncommon to be able to see light between the sill plate/basement wall, that's why I said the air sealing part makes such a huge difference)
I like the foil faced polyiso because it cuts nice...and you can cut it without foam "crumbs" going EVERYWHERE!

Need some pics...but I don't see why this would be a problem, especially for the short term.

 

If it is wind then you need to stop the wind-usually with foam of some sort. But it needs to be an effective wind barrier. AKA air sealing. Then if you also have heat loss because of insufficient R value between a heated and non-hetaed space you can add insulation at that point of loss.

 

Once again thanks for all of the input gents! Looks like I have work to do this week/weekend

 

Your house is a box if the exterior walls and "roof" are insulated all the heat is inside that box. If you insulate the floor between the basement and first floor you have now created a box inside a box, more than likely the basement will become very warm and the first floor will cool down.
The only advantage to insulating that floor would be if the basement was unconditioned space.
Seal all your sill plates and the band board above the sill plate this will be your largest leak area, it is on most homes. IMO if you get the band board sealed all your problems will be solved.

 

As far as ceilings in basements go, no matter how careful or how much planning ahead you figure into it, there will always be some reason for the ceiling to be accessed. It will be a fun day when that happens for you.

I have seen finished basements with black painted ceilings (floor joists and everything else painted black-wiring plumbing you get the idea) and they actually look good. Best part is, everything is just as accessible as it ever was. Its a basement for pete's sake, no?

I would not insulate the ceiling in the basement either, joining those opposed to the idea.

 

Finally got a chance to check the rim joists in the basement. It looks as though they have rigid insulation installed with fiberglass insulation behind them. I definitely need to use some canned spray foam around the edges. I could feel cold air coming in. I'm gonna spray foam where they sit on the foundation walls as well as brenndatomu suggested. The main culprit of cold air seems to be coming in above the ceiling from the garage though. For now I'm gonna stuff some rock wool up there and come up with a more permanent solution this summer. The rim joist insulation reinforcement will happen this summer too. No wonder we have always had a spider problem in the winter months

Now some pics...

 

I did all my rim joists and sill plates on one side of my basement when I finished it a few years back. Just got done with the unfinished side a few weeks back. 2” xps air sealed with great stuff and sill plates sealed with great stuff. It was a PITA and a messy job. Also went through upstairs and sealed all the outlets and switches on exterior walls. Totally worth the work. I can actually tell a difference in how the wood stove and furnace perform and how it feels in the house. Wife says there’s no way I can tell a difference but for sure I can. I guess I’m more tuned into that kind of stuff than she is.

 

Do you have an OAK for your wood stove Marvin ???

 

I did my sister's like this:

Cutting the rigid foam smaller than the cavity so there would be room for expanding foam on all 4 sides. There were places you could see outside and mice and / or chipmunks were coming in before I wind sealed with the rigid foam. I found stashes of acorns on some of the sills. I used the foil coated rigid foam though . Regular glass insulation beside the foam. HUGE difference in the temp of the basement .

 

I always thought that the foil facing was directed towards the conditioned space?