Sealed grow . . . 6 mil plastic needed behind sheetrock?

[HydroDawg421]

I'm building a new home and the detached garage will have a 15x19 sealed grow room. All (4) 9' walls and the ceiling will have spray-in closed cell foam insulation.

Do you think it's necessary to cover the walls with a thick heavy black 6 mil plastic prior to installing the purple sheetrock?

THANKS!

 

[GNOME GROWN]

It wouldn't hurt. When I built my old glass blowing studio I put plastic over the insulation before sheet rocking the walls. It for sure helps imo.

 

[NaturalFarmer]

I don't think it is necessary if you tape and mud well, especially if you are using foam behind it. I would recommend getting a roll of tuck tape (red sheathing tape) to seal you joints prior to mud. Stickiest and strongest tape I have ever found.

 

[BigHornBuds]

One big advantage of the spray foam , is that once’s it’s dry it doesn’t need vapor berrier . It’s a sealed membrane.

 

[brewbeer]

Closed cell foam is a vapor barrier. If you were using an open cell foam, you would want to use a vapor barrier appropriate for your climate.

 

[thumper60]

I'm building a new home and the detached garage will have a 15x19 sealed grow room. All (4) 9' walls and the ceiling will have spray-in closed cell foam insulation.

Do you think it's necessary to cover the walls with a thick heavy black 6 mil plastic prior to installing the purple sheetrock?

THANKS!

View attachment 4098077

if u r using outside walls an have snow on the ground 3-4 months a yr poly it cheap cant hurt.if its a room in a room don't bother

 

[OldMedUser]

Any power outlets on an outside wall can get a lot of condensation in them too if you get cold winters. I take the cover plates off those, put a piece of plastic over them and screw the cover back on then just plug in right thru the plastic and get a good seal. Also don't vent into your attic unless you want it to rain inside come spring. I found out the hard way.

I would put that cheap clear plastic over the insulation too. For a few extra dollars it's worth it.

 

[cookie master]

you are gonna seal in moisture and the whole thing will melt. Dont do shit like this yourself, trust some experts, not me.

 

[thumper60]

Any power outlets on an outside wall can get a lot of condensation in them too if you get cold winters. I take the cover plates off those, put a piece of plastic over them and screw the cover back on then just plug in right thru the plastic and get a good seal. Also don't vent into your attic unless you want it to rain inside come spring. I found out the hard way.

I would put that cheap clear plastic over the insulation too. For a few extra dollars it's worth it.

I have seen brandnew garage rotted in 1 yr from blowing into attic of cold air like u say it had been raining up there for months I have seen extearer walls warped from not using plastic on them,if it stays above freezing don't get that problem

 

[thumper60]

you are gonna seal in moisture and the whole thing will melt. Dont do shit like this yourself, trust some experts, not me.

hes running seal room witch means co2 an a dehuy

 

[Joint Monster]

Closed cell foam is a vapor barrier. If you were using an open cell foam, you would want to use a vapor barrier appropriate for your climate.

This guy seems to know what is is talking about. While I am no contractor, I know that vapour barrier (plastic) is used over insulation for a reason, controlling moisture.

However, Brewer says closed foam is a vapour barrier. So I would presume you are okay. You can always inquire with a contractor for a quote over the phone, and if they're a good contractor they will quote you for free and tell you if it is necessary or not. Then you can simply go forward by yourself.