Around here a lot of contractors won't look at a job for under $10K. They consider it a service call. You get a broad estimate over the phone and if you want, a crew shows up to do the job T&M
Enough of COVID...what are you doing to the house?
- Thread starter mimico_polak
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We were worried about that too. Glad that we can get them in.
Mad Mike
Well-known member
That’s a reasonable price, in line with what I’d expect to pay.
If you could DIY you’d be about $750 using rock wool or fibreglass. (DIY spray foam materials cost more than having the whole job sprayed by pros).
I don't even know if you can get DIY closed-cell. I looked into buying a diy set to do some rim joists and it made no economic sense so I canned the project.
Mad Mike
Well-known member
You can get it, I got some for free from a friend who declared it surplus at his job site ( he manages a large gov building - the union would not ok their in-house guys to apply without a $5000 training certificate).
My first time - ****-simple!
If I had the time and inclincation I'd demo the ceiling myself and have a stab at drywalling it afterwards renting a drywall lift to save the majority of labour costs. As it is things are a bit busy and at my age my free time is a premium. That premium costs a fair bit.
Mad Mike
Well-known member
I get that.
For me I see 1 day demo, 1 day to install vapor barrier and 4 sheets of drywall, and 1 more day for finishing work.
And $5k made available for motorcycle debauchery!
Another alternative is foam sheets, sold in 4X8. R5 per inch is common and it can be cut and layered between the joists with a full sheet below the joists for a full thermal break. Many are also foil backed to provide a reflective benefit.
One thing with spray foam is it is slightly higher per inch BUT are you getting the full depth everywhere?
One thing with spray foam is it is slightly higher per inch BUT are you getting the full depth everywhere?
The quote says 5” plus as they weren't sure of the size of the ceiling gap. It'll be done to the joist level so completely filled.
It's hard to install foam sheets in joist bays in a way that is vapor tight. I would spring for the spray foam in this situation.
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IME and from what I have seen they never totally fill it to be fully flush with the bottom of the joists right across.
It would take some mad skill to spray it in just right so it expands to be exactly flush in the end. If it expands below the joists the drywall won't sit right. They do not want to pay the labour to cut it flush if it over expands, so..
You spray too much and then use the joists as a straight edge to shave back to flush. Obviously this causes some waste and takes some labor so it costs more than stopping short.
Mad Mike
Well-known member
I’ve done it with 4”eps sheets a complete seal is made with a bead of acoustic sealant or spray foam from a can (the stuff for sealing windows).
I also use eps on basement walls instead of spray foam. A sheet glued to the bare foundation walls sealed with foam is fantastic - you can frame with steel as it provides a complete thermal break. I often use steel studs for long wall because you can make them perfectly straight - no cupping, twisting or nail pops.
Deposit paid. They are coming in to do an asbestos test next week (there isn’t any but it's obligatory it seems). Will pay a little extra to have them finish the painting too. The guy said the foam would be level with the rims so I guess they trim it back. Looking forward to having a functional room, unless they find something serious with the roof in which case I'll just resort to emptying the liquor cabinet.
Mad Mike
Well-known member
Can’t do that. The rafters must be foamed over completely bottom side to complete the thermal break and continuous Vapor barrier, otherwise you have a thermal bridge. drip, drip, drip.
If the rafter is the ceiling joist, the ceiling has to have eps sheeting separating the joist and drywall. Alternatively strapping with fibreglass insulation and a 6mil poly Vapor barrier. .
Mad Mike
Well-known member
Do you have foam insulation between the roof deck and roof membrane?
Nope. Torched down layers of heavy tar paper with an asphalt coating thing on top on the plywood.
It's a **** roof but it's watertight.
Mad Mike
Well-known member
Is the roof deck on one side and drywall on the other side of the rafter?
Asphalt roll stuff, several layers of heavy tar paper, plywood, batt insulation and drywall is what's there. Can't remember if they call this a hot or a cold roof. It's ******* hot in the summer and ******* cold in the winter in the room underneath though. Hopefully that will change soon.
Mad Mike
Well-known member
That’s a problem, quite likely the cause of your moisture.
You need a thermal break between the drywall and rafters, otherwise the rafter acts as a thermal bridge. Condensation forms on the bridge, gravity brings it to the drywall side.
In a roof like that, you need to break the bridge with a layer of insulation between the bare wood rafter and the drywall.
This is done by either foaming over the bottom sides of the rafter, sheeting and taping with 1” eps before hanging drywall, or strapping perpindicular to rafters and insulating with fibreglass or rockwool then adding a 6mill poly Vapor barrier between the insulation and drywall.
Changing from fibreglass to spray foam will offer better insulation, but unless you’re fixing the thermal bridge, your moisture problem will be the same.
If all you’re missing is a thermal break, the easiest and most economical fix is to strip drywall, add 1” of eps, tape the seams and replace the drywall. I wouldn’t bother with the spray foam, that’s not going to fix the moisture unless they strap then foam over the rafters. Changing from fibreglass to spray foam isn’t the solution it’s an unnecessary expense with no ROI.
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