Fireproof covering for inside foam?

[Innovate1]

Was planning to insulate my slab edge and foundation walls which will stick up 2 ft above the floor like this.

But found out I can't put OSB over the foam. Has to be fireproof so drywall or ?? Any other ideas? Drywall is going to get pretty banged up I think. Someone local suggested to just put expansion joint filler around the edge and leave off the insulation above the slab. Then add the upper foam and whatever cover I wanted after final inspection but I would like to do it per local code if it isn't too impractical.

 

[larry4406]

Put 5/8" type X drywall over it to achieve the fire rating needed. Later overlay the drywall with OSB/plywood of your choosing?

 

[Jlbc212]

You could use cement board, such as Hardie Cement Board or Durock. Both are moisture and mold resistant.

 

[climb.on]

Very good discussion here on this topic. Hardie, durock, and certainly sheetrock and OSB are poor choices. As they will all extend below grade (by code) in this application. Hardi is often suggested, but I have seen Hardi come apart with freeze thaw cycles, near grade, and it's not rated for use below grade.

 

[stm317]

If FRP board would pass code, it might be a decent option. It's super easy to clean, pretty durable, and water/moisture proof which are all attributes that sound pretty nice for a lower wall covering.

 

[Innovate1]

Very good discussion here on this topic. Hardie, durock, and certainly sheetrock and OSB are poor choices. As they will all extend below grade (by code) in this application. Hardi is often suggested, but I have seen Hardi come apart with freeze thaw cycles, near grade, and it's not rated for use below grade.

This is not for outdoor or below grade. It is indoor covering of foundation wall from the floor up. See the subject line...It may see a bit of moisture at the slab but that shouldn't be much - for that I could hold the sheeting (whatever it is) up a inch and use a PVC baseboard.

OSB/Plywood over drywall is apparently not acceptable either as the outer surface has to be non-flammable. I could apply the OSB after final and paint it so it wasn't obvious it was OSB... Not sure what the problem is with this. I can put a wood cabinet up against the wall so I fail to see the practical difference.

Not sure if FRP is acceptable - need to check.

 

[Jlbc212]

CertainTeed makes Extreme Impact Resistant Drywall.

https://www.certainteed.com/drywall/products/extreme-impact-resistant-drywall-m2tech/

There are commercial distributors, such as Kamco, that list and probably stock the product. I've never had any problem buying from Kamco. Cash is king!

 

[blkhonda1991]

what building code is your municipality using? also what is the need for the nailer on the interior and exterior of the foundation wall?

dont know if this is the code MO is using since they dont clearly have it on their website but accorinding to the 2012 IRC

2012 IRC: R316.6 Specific approvaL Foam plastic not meeting the
requirements of Sections R316.3 through R3l6.5 shall be
specifically approved on the basis of one of the following
approved tests: NFPA 286 with the acceptance criteria of
Section R302.9.4, FM4880, VL 1040, or VL 1715, or fire
tests related to actual end-use configurations. Approval shall
be based on the actual end use configuration and shall be performed
on the finished foam plastic assembly in the maximum
thickness intended for use. Assemblies tested shall
include seams, joints and other typical details used in the
installation of the assembly and shall be tested in the manner
intended for use.

if the foam complies with those tests you dont even have to cover it...verify the specs on the foam.

 

[matt_i]

Aluminum diamond plate (sheet....1/8" thick)

 

[Innovate1]

Code is here and references IBC2009:
https://www.stlouisco.com/Portals/8/docs/document%20library/public%20works/code%20enforcement/notices/codes/13-0128-CodeUpdating-2013Building.pdf

Diamond plate would look sharp! A little over budget unfortunately...

The outside nailer is for siding as the foundation sticks up about 30" above ground. The inside nailer is for fastening whatever goes over the foam board.

 

[benjamintmiller]

You can use an intumescent paint. Here is an example, with a video showing its effects:
https://shop.rdrtechnologies.com/DC315-Fire-Retardant-Paint-for-SPF-p/dc315.htm

 

[blkhonda1991]

Code is here and references IBC2009:
https://www.stlouisco.com/Portals/8/docs/document%20library/public%20works/code%20enforcement/notices/codes/13-0128-CodeUpdating-2013Building.pdf

Diamond plate would look sharp! A little over budget unfortunately...

The outside nailer is for siding as the foundation sticks up about 30" above ground. The inside nailer is for fastening whatever goes over the foam board.

if this is a garage for your house it would fall under the IRC not IBC but it looks like the 2009 version not the 2012 version i referenced but the language appears to be the same if you can show the building official it passes those tests you can cover it with whatever you want or not cover it at all.

 

[Innovate1]

Here is the reply I got when I asked about the issue:

If you wish to install foam insulation without the required barrier, then you would need to show that it complies with section R316.6 of the 2009 IRC. This mainly pertains to the testing methods used, and you should be able to obtain it from the manufacturer or distributor of the material. I do not believe there is an exception for the ½” drywall with the use of foam insulation in a garage. If you wish to cover the drywall with plywood, then it would have to have a maximum flame spread of 200 and a maximum smoke development of 450. I believe that most plywood complies with this, but you may be requested to provide a materials spec sheet to show it.

------------
I looked up some info on DOW foam and it meets 2009 IRC. I also looked up the numbers on OSB and plywood and most seem to meet the numbers stated although making sure I can get data on the particular material I get could be an issue.

I don't understand the part about no exception for 1/2" drywall so will get clarification on that. I think they may be saying the stud wall has to have drywall regardless of if foam is used or not which doesn't apply to what I am doing - I plan to use drywall on the framed wall in the normal manner.

Another issue is the moisture resistance of the covering. I could hold it up off the floor slightly and use some sort of moisture resistant baseboard - PVC or vinyl. I suppose if they got really picky they could say that makes a gap in the covering but covering shouldn't matter if the foam is on concrete.

 

[Innovate1]

here is the info on the DOW insulation. The attached garage may be an issue - I'm just not sure from reading this. The detached garage seems to be ok.

http://www.greatlakeshomeperformance.com/wp-content/uploads/2015/02/ICC-ES-Styrofoam-ESR-2142-Code-Report.pdf

 

[rburke65]

I would just use the concret board. I have tool chests, tool always, cabinets around the perimeter of my shop....how chewed up can it get?

 

[spike99250]

They do make a fire rated plywood.

 

[Innovate1]

I was just told there is no exception for garages means that I have to use drywall (or similar for fire/thermal break - not plywood). I can put plywood/osb over the drywall. Looks like this may just be for attached garage as detached garages are noted in the testing for no cover. Fire rated plywood may be acceptable.

Then there is the issue of moisture collecting on the cold walls under the insulation during the heating season.
This is getting complicated...

Rburke65, what concrete board are you referring to? Backer board used under tile?

Was told drywall (or other covering) must go to the floor. Seems like a bad idea even for moisture resistant drywall as the floor will get wet occasionally.

 

[blkhonda1991]

I was just told there is no exception for garages means that I have to use drywall (or similar for fire/thermal break - not plywood). I can put plywood/osb over the drywall. Looks like this may just be for attached garage as detached garages are noted in the testing for no cover. Fire rated plywood may be acceptable.

Then there is the issue of moisture collecting on the cold walls under the insulation during the heating season.
This is getting complicated...

Rburke65, what concrete board are you referring to? Backer board used under tile?

Was told drywall (or other covering) must go to the floor. Seems like a bad idea even for moisture resistant drywall as the floor will get wet occasionally.

it doesnt specifically exclude attached garage..."or other structures under ibc or irc, with no covering..." did you show the code official the data on the insulation?

 

[rsanter]

Hardboard or galv sheet metal

 

[Hilltopmasonry]

Was planning to insulate my slab edge and foundation walls which will stick up 2 ft above the floor like this.



But found out I can't put OSB over the foam. Has to be fireproof so drywall or ?? Any other ideas? Drywall is going to get pretty banged up I think. Someone local suggested to just put expansion joint filler around the edge and leave off the insulation above the slab. Then add the upper foam and whatever cover I wanted after final inspection but I would like to do it per local code if it isn't too impractical.

They have a concrete coating that you plaster over the insulation board...that would be perfect

https://www.homedepot.com/p/STYRO-I...rey-Tuff-II-Foundation-Coating-TTCG/203009633


Sent from my iPhone using Tapatalk

 

[Innovate1]

it doesnt specifically exclude attached garage..."or other structures under ibc or irc, with no covering..." did you show the code official the data on the insulation?

I wondered about that too but was under the impression other did not include homes and attached structures that may have been previously covered somehow but didn't see where that was clearly spelled out. I sent the question to our code dept.

I sent it to my plans guy and got back the detached garage with foam above and below the floor but an expansion joint for the floor itself. Not sure why he did that and will be making it foam as well. He didn't put anything above slap for the attached garage. Will see what the code people say...

 

[lakeroadster]

Any other ideas? Drywall is going to get pretty banged up I think.

Have you considered steel barn siding?

 

[Innovate1]

Code person said it was ok for attached garage when I gave them the test sheet and pointed out the "other" structures bit. They noted I should keep a copy of the document on site and I needed to make sure that particular foam was used. Sounds like it is likely to be questioned during inspection so I will make sure it is detailed in the plans that get approved.