Attaching foam board to ceilings

[Burl]

When I built the garage a few years ago, I used 1/2" foam board 4X8 sheets for the ceiling and attached them to the wood joists with the orange plastic discs used to attach roofing felt paper screwed on with drywall screws. They are small, maybe about an inch diameter, and now they are starting to pop off (the screw stays, the plastic discs break). What have others used to do this? I would like something like the orange things, just much larger.

 

[73fxe]

Fender washers and screws?

 

[cruzinZ]

I used some sheet metal screws and cut down some thin sheet metal to 3"x3" squares to attach a foam board to the garage door of my old home. I would suggest this as the metal would not deform like the plastic retainers you currently are using.

 

[The Cobbler]

I second fender washers.

 

[bikesandcars]

I used 1/4" fender washers and 3" screws for rigid foam around my skirt board and it worked awesome

Sent from my XT1585 using Tapatalk

 

[Git]

take a look at this link

http://rodenhouse-inc.com/brand/owenscorning/

or

https://www.amazon.com/gp/product/B00FPQQ2UQ/?tag=atomicindus08-20

https://www.amazon.com/gp/product/B00CMDECA2/?tag=atomicindus08-20

 

[astroracer]

Get some 1 x 3 lumber. Screw that through the foam into the lower rafter cord. Pant them white or silver before you put them up. No more worries as the strapping supports the foam between joists. My ceiling has been like this since 1987 with no issues. It will also support any batt insulation you want to throw on top of your foam. Mine has 6" Fiberglas on top of it.
Mark

 

[rkevins]

not sure if they are made anymore but you could get cap nails that had a metal disk

 

[jarhead]

I used these that I bought from Home Depot or Lowes. I removed the nails and used a long screw. I ran them into strapping that was ran the opposite direction as the trusses.

https://www.amazon.com/dp/B000VOQT46/?tag=atomicindus08-20


You can see the "orange" heads on each side of the fluorescent.

 

[Crazyjake8493]

When I built the garage a few years ago, I used 1/2" foam board 4X8 sheets for the ceiling and attached them to the wood joists with the orange plastic discs used to attach roofing felt paper screwed on with drywall screws. They are small, maybe about an inch diameter, and now they are starting to pop off (the screw stays, the plastic discs break). What have others used to do this? I would like something like the orange things, just much larger.

I think you tightened the screws too far. I did the same thing in my garage, 1/2" Polyiso attached with 1-5/8" drywall screws and plastic cap washers. Haven't had a single plastic washer break after a few years.

I drove the screws just enough to pull the foam board tight to the ceiling joists, but didn't try to countersink them at all, like you would do with drywall.

If your plastic washers are breaking, I'd probably go with some fender washers.

 

[NUTTSGT]

I've had mine up for years basically without issue with plastic cap nails. I also covered the head with a piece of foil tape for cosmetic reasons. My 1/2" is on 24" centers, how far are you spanning ?

 

[KenC]

I'd be more concerned with fire spread from the exposed foam! No reference , but the building code requires cover by an approved product, like gypsum board, at least residential.

I've seen the results of a fire in a metal building with exposed flammable insulation, not pretty. My grandson was working in it at the time, a fire broke out in one corner on top of little office. Caused by a bad splice in the ceiling light fixture or J box. In less than 3 minutes the fire traveled the full length and width of a 120x80 because of the plastic bubble junk!

Nasty stuff too, as the dripping, burning plastic lit everything it hit. Luckily no people were injured. If you've ever seen foam burn, it is the same way.

 

[Crazyjake8493]

If you've ever seen foam burn, it is the same way.

Except that it isn't. Maybe styrofoam, I'm not sure about polystyrene products. But Polyisocyanurate is a thermoset material, so it will burn and char but not drip and run everywhere. Still best to be covered with drywall when possible.

 

[bandaidmd]

they make a plaster washer to repair loose plaster, its like a fender washer but has a little shape to it so the drywall screw sits flush. They work great for foamboard.
https://www.amazon.com/dp/B008AY2MS6/?tag=atomicindus08-20

 

[KenC]

Except that it isn't. Maybe styrofoam, I'm not sure about polystyrene products. But Polyisocyanurate is a thermoset material, so it will burn and char but not drip and run everywhere. Still best to be covered with drywall when possible.

You're right of course, but 2 out of 3 ain't bad!

Styrofoam and polystyrene drip, smoke and burn like crazy.

Not knowing what the OP has, I thought the warning was warranted.

No exposed foam in my shop, of course I cut and weld in there so fire is a risk.

 

[ilovevocs]

You need to go to a commercial roofing supply house and ask for insulation plates. They are 3" in diameter. Or contact a commercial roofing company and see if they will sell you a few hundred. They come in buckets of 1000.

http://www.rubberroofs.co.uk/shop/sku/23/firestone-insulation-plates

 

[gungatim]

I put up 1.5" foam on my ceiling and used fender washers/2.5" screws except for the corners, there I just cut some squares of luann plywood and used those. spray painted them black and they blend in. also makes it easy to pull down a panel to hide a body in the attic if I ever need to...

 

[Firebird 1]

A regular old roofing nail will do the job.

 

[pstnbly]

2 word, roof tins

 

[Crazyjake8493]

You're right of course, but 2 out of 3 ain't bad!

Styrofoam and polystyrene drip, smoke and burn like crazy.

Not knowing what the OP has, I thought the warning was warranted.

No exposed foam in my shop, of course I cut and weld in there so fire is a risk.

Always better safe than sorry! I have foam board ceilings and I only TIG weld indoors. Anything I need to stick weld is done outside. Even without the foam, stick welding indoors makes me nervous.

I wanted to drywall my ceiling but I was worried about the extra weight. 400 sq ft of even just 3/8" drywall would've been about 500 lbs.

I only have 2x4 ceiling joists, supported by a probably undersized beam, which is supported again by a beam perpendicular to that one. I'd like to replace the first beam with a properly sized one someday, but one end rests on the garage door header. I'd probably have to go with a steel I-beam, since an LVL beam would likely be too tall to sit on the header. And even then, I'd probably have to beef up the header. That's a big project that'll have to wait until all the other stuff is done.

I only store extra insulation and sonotubes in the attic, trying not to add any unnecessary weight.

 

[jekquist]

Glad this came up. I'll be putting foam up next week sometime

 

[fastjohnny]

This! I used 3 1/2" polyiso laminated to 1/2" OSB on the underside of a leanto bay, fastened with long screws through these plates.

You need to go to a commercial roofing supply house and ask for insulation plates. They are 3" in diameter. Or contact a commercial roofing company and see if they will sell you a few hundred. They come in buckets of 1000.

http://www.rubberroofs.co.uk/shop/sku/23/firestone-insulation-plates

 

[jekquist]

These and 1 5/8" scews worked great for me. Ideal Security Inc. SKPHC 500/Box Plastic Cap Washers, White Plastic https://www.amazon.com/dp/B005TE3C1G/?tag=atomicindus08-20

 

[info2x]

Search on McMaster for "Washers for Foam Insulation"

I used something very similar when I used KERDI board for tile work.

 

[Crazyjake8493]

These and 1 5/8" scews worked great for me. Ideal Security Inc. SKPHC 500/Box Plastic Cap Washers, White Plastic https://www.amazon.com/dp/B005TE3C1G/?tag=atomicindus08-20

This is what I used as well. They work great. You just have to treat it like you're screwing drywall, not plywood. Don't overtighten.

 

[jekquist]

This is what I used as well. They work great. You just have to treat it like you're screwing drywall, not plywood. Don't overtighten.

Yup. It did take me forever to do. I did tape every single joint with foil tape(until I ran out). That really sealed everything up tight.