# Hanging drywall on foam.



## Mr.Brightstar

I looked at a job and All the interior walls are foam block, Poured concrete walls. I was told to glue it with Dobbs And screw it. Has anyone ever installed drywall on foam before, And is there anything I should look out for?


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## chris

Yes. It was Exterior walls though. Be on the lookout for blowouts in the walls and they are usually really crooked. Plan on a tad bit longer screw and maybe shims. It will come close to twice as long to hang :yes:. I have done 4 homes with it and only 1 of them was done right.


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## Mr.Brightstar

chris said:


> Yes. It was Exterior walls though. Be on the lookout for blowouts in the walls and they are usually really crooked. Plan on a tad bit longer screw and maybe shims. It will come close to twice as long to hang :yes:. I have done 4 homes with it and only 1 of them was done right.


Yes the interior side of the exterior walls. The walls looked flat, I didn't check them with a straight edge. What size Screw do you use and what do you screw into wood, concrete, or Metal?


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## chris

1 5/8" screws for 5/8. Screwed into steel. Didnt use glue. Tere are slats of steel to screw to every 16" ???? :whistling2:


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## moore

The ones [2] that I've seen.. had plastic strips to fasten the drywall to.
Both were way out of wack! The next big thing didn't last too long around here. ..Pretzel studs work best!:whistling2:

hack built factory trusses on 24'' center with double crowns work out GREAT!:thumbup:


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## DrywallerDustin

I did one not too long ago that had plastic backing in the foam every 8 inches, it was actually pretty sweet to hang, only a couple spots that were not too straight.


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## SlimPickins

There should be vertical lines every 8", and they should be marked in some way, that's where you screw. Sometimes they are steel (light gauge) and sometimes plastic. You'll need at least 1-5/8" screws, and my experience shows that fine threads work better.....the coarse screws tend to strip out more. Oh, and if the tabs are plastic, run your screws in at low RPM so you don't melt a hole in the tab.

Things to look out for: Are the blocks lined up everywhere? If the tabs aren't lined up, you'll spend 2-3 times longer trying to find where you're supposed to be fastening....frustrating, and expensive labor wise. You'll also want to find a way to mark the seams in the courses of block themselves.....the tabs are _not _continuous (with most systems), so you'll wind up with duds if you hit the block seams. 

If you're going to use glue, make sure to get non-foam-corrosive glue....you'd hate to have your sheets fall down down the line. 

These jobs are a bitch to hang by yourself, you can't slide your arm behind the sheet in a stud bay, it's all fingertips. When I have an ICF job, I always wish that I had a cordless autofeed gun. 

But most of all.....have fun!


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## 2buckcanuck

DrywallerDustin said:


> I did one not too long ago that had plastic backing in the foam every 8 inches, it was actually pretty sweet to hang, only a couple spots that were not too straight.


Are you talking about this stuff here, that's what we see where I live.

Tape wise, you notice it when you run your boxes, but it's not that bad, a wee bit wavy:yes:


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## Mr.Brightstar

2buckcanuck said:


> Are you talking about this stuff here, that's what we see where I live.
> 
> Tape wise, you notice it when you run your boxes, but it's not that bad, a wee bit wavy:yes:


Yes, There weren't any plastic strips to screw to, or any markings to see where to screw. That stuff was in the basement and main floor.


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## SlimPickins

Mr.Brightstar said:


> Yes, There weren't any plastic strips to screw to, or any markings to see where to screw. That stuff was in the basement and main floor.


The markings (on the stuff I have worked with) were almost unnoticeable x's which were raised on the surface of the foam. Once you knew what to look for you could see them.

If there are no tabs to fasten to (which seems doubtful, because the tab system is also part of the structure of the block, it's what keeps them from spreading when you pour the concrete in), then you're looking at glue and braces. I suppose you could run fat gyp-screws into the foam to hold the sheets in place while the glue sets, or something similar.


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## mld

My preference is to hang RC1, (some call it sound channel) to the strips and then rock over that. Sometimes the foam puts pressure on the rock when you fasten directly to it and when you spot the screws they pop. If we have to fasten directly to the foam, we use spray foam instead of glue, just don't overdo it.:thumbsup:


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## gazman

My one and only experience with this type of thing was about 8 years ago. The system used was Thermacell, it consists of polystyrene blocks core filled with concrete. This system had no channel or plastic to screw too. All of the rock was glued to the foam. We did screw coarse thread screws into the foam in some places to keep the sheets even. These were removed prior to taping. So when it was all said and done the glue was the only thing holding the sheets on. The glue we used has an acrylic base. Anything with a solvent base will melt the blocks. 

The home won some awards and is featured on the Thermacell web site. Here it is.
http://www.thermacell.com.au/media-downloads-portfolio/portfolio/award-winning-homes


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## skim-coat

ICF is insulated foam concrete, there's all types of them out there. Some have metal strips and some have plastic to screw to. you are going to need foam glue and the regular dry wall screws you normally would use


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## skim-coat

there will be a notch on the foam block to show were the strip is to screw in to.:thumbsup:


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## skim-coat

charge more money to do this for the difficulty


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## DrywallerDustin

2buckcanuck said:


> Are you talking about this stuff here, that's what we see where I live.
> 
> Tape wise, you notice it when you run your boxes, but it's not that bad, a wee bit wavy:yes:


Looks similar, the plastic was recessed into the foam 1/2" so other than the little x's you couldn't see it. about 2' by 4' blocks?


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## friesendrywall

Kind of late to this party but..

I always use all 5/8 drywall on any foam job, for sure ICF. The jobs always go a little slow. I mark every icf stuf on ceiling and floor. Don't screw top and bottom board edges, always come into the board about 8 inches, otherwise the screws pop because the edges are hard, and the springy foam. Reasons for 5/8"? 1/2" creates about a 8 to 10" depression because its not stiff enough.

Also, be VERY careful with butt joints. Butt joints have no integrity over foam. Be sure you at least don't orphan butt joints, (IE, single joint over headers) and preferably cut foam and place a butt board of some sort.

Also, don't be surprised if you need to run the nails 4 times because of aforementioned depression problem.


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## friesendrywall

double entry, how to delete?


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## Mr.Brightstar

friesendrywall said:


> Kind of late to this party but..
> 
> I always use all 5/8 drywall on any foam job, for sure ICF. The jobs always go a little slow. I mark every icf stuf on ceiling and floor. Don't screw top and bottom board edges, always come into the board about 8 inches, otherwise the screws pop because the edges are hard, and the springy foam. Reasons for 5/8"? 1/2" creates about a 8 to 10" depression because its not stiff enough.
> 
> Also, be VERY careful with butt joints. Butt joints have no integrity over foam. Be sure you at least don't orphan butt joints, (IE, single joint over headers) and preferably cut foam and place a butt board of some sort.
> 
> Also, don't be surprised if you need to run the nails 4 times because of aforementioned depression problem.


What's the best type of glue to use for drywall on foam, is it also suitable for wood.


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## friesendrywall

Use foam glue, something down this type of product - http://www.demandproducts.com/item.php?l1=&sku=GROUPENERFOAM
I something similar on an ICF project, and it seemed to work well.


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## moore

friesendrywall said:


> Kind of late to this party but..
> 
> I always use all 5/8 drywall on any foam job, for sure ICF. The jobs always go a little slow. I mark every icf stuf on ceiling and floor. Don't screw top and bottom board edges, always come into the board about 8 inches, otherwise the screws pop because the edges are hard, and the springy foam. Reasons for 5/8"? 1/2" creates about a 8 to 10" depression because its not stiff enough.
> 
> Also, be VERY careful with butt joints. Butt joints have no integrity over foam. Be sure you at least don't orphan butt joints, (IE, single joint over headers) and preferably cut foam and place a butt board of some sort.
> 
> Also, don't be surprised if you need to run the nails 4 times because of aforementioned depression problem.


Ya mean eggholes?:blink: Blisters!!!


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## Mr.Brightstar

Pita!


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## gazman

This works. It is an acrylic stud adhesive.


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## Mr.Brightstar

gazman said:


> This works. It is an acrylic stud adhesive.


Thinking of Notch troweling durabond onto the foam then screwing off the Perimeter. 

The original plan is spray foam glue.


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## moore

Those werner benches are known world wide ain't they? What drywall man don't own at'least one?:thumbup:


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## moore

Mr.Brightstar said:


> Thinking of Notch troweling durabond onto the foam then screwing off the Perimeter.
> 
> .


A/p would probably stick / hold a little better J/S!  YES! That looks like A pain in the as$!


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## boco

What a pain in the dic. I was thinking about getting the hercule 42 60. I was thinking a job like this it would be useful. just something to hold the sheet in place for a while while foam or glue dries. Never used the top sheet kicker tool but any input would be nice.


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## Bevelation

90% of the basement foundations on jobs done here use some sort of ICF block, so I have very quickly become familiar with these animals, whether it's ARXX brand like 2buck showed, Fox blox, Nudura, or Logix. The Arxx are easiest to install board to because the tabs are exposed. Most others that have the tabs hidden need 2" screws from what I've found. The issues my crews had mainly was when the builder screwed up on the layout causing the tabs to not line up. Not cool to float butts even when the tabs are 6" or 8" on center. The other thing that can happen is that the blocks get installed out-side in, and although the tab markings are on both sides, the tabs are deeper into the foam on some and you're forced to use 2".

Tip: treat ICF like it is steel that you can glue. Pl300 or dispensed expanding foam will work great. Use fine thread screws for plastic. Coarse thread can strip the plasic easily and they are difficult to control depth going in. Hope this helps.


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## dieterschmied

*using foam to hang drywall*

I recently bought foam drywall adhesive under the brand name of Dr.Schenk (it used to be sold by Senco) and I bought some 4x8 sheets of foam Isoboard (foam sandwiched between cardboard) which is 1" thick and can be bought at roofing supply stores. 

I needed to wallboard a brick wall.

I used the drywall adhesive and applied the foam in beads 12" apart and slapped the isoboard immediately on the brick wall; you need to get it pretty close because there wasn't much time for dallying. I let this set for a day but this could have been put up with screws and 3" plates the way it is normally attached on roofs. At this point, I had a nice smooth wall that could have been tapped and painted, I wanted drywall.

Then I put beads of the Dr. Schenk faom drywall adhesive on the mounted isoboard , again at 12" approximate intervals and I slapped 1/2 " drywall boards ( could have been thinner boards) onto the isoboard and held it in place for a few minutes and paid attention to possible slipping down because of gravity. I also put the drywall at ninety degrees so I could overlap joint lines of the isoboard but it didn't seem to be a problem anyway. I used no screws. My big problem is tha Senco discontinued selling that product. I talked with Dow about using their Great Stuff insulation in a can for a similar application, but I think it might expand to much but if you slide the wallboard a little to break down the cell structure of the foam, I think it might work. In either case, once it sets up, you won't need screws.

Since I wrote this I lucked out on the Dr Shenk brand that was handled by Senco. It seems that Dr. Shenk was Polish company and has since been bought by Selena FM S.A. with a place in Holland , Michigan but they dropped the Dr. Shenk name. They have a full line of construction stuff and competes head on with Dow and Great Stuff.


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## dieterschmied

what is it about? all the photos above and no explanation.


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## Bazooka-Joe

I bid a whole house like that board and Finnish i did not give a break on price


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## dieterschmied

*make sure you are not using insulation foam*



friesendrywall said:


> Use foam glue, something down this type of product - http://www.demandproducts.com/item.php?l1=&sku=GROUPENERFOAM
> I something similar on an ICF project, and it seemed to work well.


I think some did not make much of an effort to find out what they are working on. First of all what kind a screw will hold in foam????

As to the foam wall adhesive suggested, you might want to test with a couple of foams. Enerfoam takes longer to set up according to Dow. Do you want to hold it till it sets up? Also using Great Stuff may not have the holding power that you need. There is a difference between insulation foam and adhesive foam. I just bought a case from a company in Holland Michigan which bought out DRSchenk; I used DrSchenk before but that actual brand is only in Europe. Get onto Google, the company name starts with an S ; Selenausa, I think.


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## thefinisher

The foam glue made by selena usa is really strong and sticky!! Only problem with it is that it is really hard to deal with. I tested it out and it isnt user friendly. It doesn't stick well to the stud initially.. so some of it falls back off. Ceilings would be a near nightmare. But I will say it is probably has 5x more adhesion than standard OSI junk. We need the glue that those aussies got :yes:


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## dieterschmied

thefinisher said:


> The foam glue made by selena usa is really strong and sticky!! Only problem with it is that it is really hard to deal with. I tested it out and it isnt user friendly. It doesn't stick well to the stud initially.. so some of it falls back off. Ceilings would be a near nightmare. But I will say it is probably has 5x more adhesion than standard OSI junk. We need the glue that those aussies got :yes:


 I don't know what the Aussies are using but I am interested in knowing the problem you had with Selena especially since I just bought a case of it. If it is not as good as the DrSchenk drywall adhesive, I will certainly inform them in hopes that they will go back to the earlier formula. It helps to let suppliers know problem and sometime they send you some new stuff gratis.


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## moore

thefinisher said:


> The foam glue made by selena usa is really strong and sticky!! Only problem with it is that it is really hard to deal with. I tested it out and it isnt user friendly. It doesn't stick well to the stud initially.. so some of it falls back off. Ceilings would be a near nightmare. But I will say it is probably has 5x more adhesion than standard OSI junk. We need the glue that those aussies got :yes:


Give tight bond a try.


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## Mr.Brightstar

thefinisher said:


> The foam glue made by selena usa is really strong and sticky!! Only problem with it is that it is really hard to deal with. I tested it out and it isnt user friendly. It doesn't stick well to the stud initially.. so some of it falls back off. Ceilings would be a near nightmare. But I will say it is probably has 5x more adhesion than standard OSI junk. We need the glue that those aussies got :yes:


we used F-38 on studs and trusses. Spray foam on the foam blocks. That stuff is incredibly strong.


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## Masterpiece

Ended up helping on a non profit project that had ICF ext walls with the same foam/strips.

Had to go behind and sink over half the screws and the other half were pushed throw the drywall (USG 5/8 lightweight, yuck).

The fastening strips were indicated in the foam blocks by 2x4 stud outlines in the foam that ran top to bottom.

However, they didn't run straight every time and there were gaps between the strips vertically where the guys could fasten the drywall.


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