Drywall over foam board insulation

[magicheater]

Drywall does better being affixed to a solid member. Putting foam in between introduces a tension factor which can lead to screw pops and other negative effects. Better to have a nailing/screwing strip for final application of drywall. Using foam is not a bad idea but it needs to be applied correctly for subsequent substrates to perform as intended and without fail.

 

[RRILEY]

were, or are there strips of wood installed on the original ceiling for your 12 inch square ceiling tiles to be stapled to? Are the original walls plaster? Do you have gable vents for the roof or the vented ridge cap?
A lot of things to consider here.

 

[RRILEY]

Don't hang pictures with hammer and nail or heavy objects.

 

[RosseauK]

Have you thought about putting the foam up then strapping it for the drywall??
Make sure you take down the current vapor barrier as the blue foam acts as one.

 

[clemsonfor]

Im not really trying to go over a problem or take the easy way out. The easy way would be no foam and keep the existing insulation and just go over it all. Im thinking of keeping the celing tiles as an extra bit of insulation.

I agfree if there is no air gap there is a problem according to you. But i thought that 6"/R19 insulation went into a 6"void, weather it be a ceiling or a wall.

I will tear some more tiles off to measure the rafter size (could just go in attic) as well as to see a label on the insulation or just measure it to see how thick it is. This room has been the way it is since the late 60's or early 70's. I know if it was done wrong then that still dosent make it right.

And like i said im not trying to cover anything up. Now is the time to fix it. Im just looking for more of a buffer between this bedroom and the hot southern sun 8"s over my head!

 

[forgeblast]

what about sprayfoam, and then just drywall over it.

 

[clemsonfor]

what about sprayfoam, and then just drywall over it.

That would work, but i would have to still remove all the old tiles(im not opposed to this im and just saying) pull the glass insulation, then pay to have it sprayfoamed (i already have insulation). Then there still is the problem in the center of the room (part with the flat celing thats not with the roof line) once i pull the tiles and insulation down, there is no backer for the sprayfoam, i would have to lay plywood as a floor in the attic space as a floor so that you have a backer to shoot spray foam onto in this area. I like the idea of sprayfoam, i just dont think it would work the best here. I could though pull the batt insulation from the slanting parts of the ceiling, spray those parts and then lay extra batt insulation into the attic space over top of the current insulation.

Keep the though coming guys.

 

[clemsonfor]

were, or are there strips of wood installed on the original ceiling for your 12 inch square ceiling tiles to be stapled to? Are the original walls plaster? Do you have gable vents for the roof or the vented ridge cap?
A lot of things to consider here.

Looks like they used cheap paneling that was nailed to the joists and stapled to that? I have no idea how they held as that seems flimsy, but the ceiling is strong and tight as is.

I have gable vents and with the new roofs instalation in a few weeks will also have ridge vents.

 

[clemsonfor]

Have you thought about putting the foam up then strapping it for the drywall??
Make sure you take down the current vapor barrier as the blue foam acts as one.

Vapor barrior Ha. This is an old house in the south they dont use those. The closest thing would be the paper back on the insulation.

But a serious question, say i did have a proper plastic vapor barrior behind the tiles against the studs/joists. Why would it hurt to put foam (with taped joints) over that. There would be 2 barriors, similar to a double layer of plastic? I guess the only thing is if moisture gets between the 2 it would never leave.

 

[Rustyiron]

I would check out another forum called greenbuildingtalk.com and find the apropriate section for your question. I knew a guy that did that many years ago but I have not spoken to him in quite a while, last I knew he had no problems.