Dow Styrofoam residential sheathing insulation used inside an attic

[Jim Luttrall]

I see the warning on the Dow Styrofoam sheets visible in the attic relating to its combustibility.
Can someone point me in the direction of approval or prohibition of leaving it exposed inside the attic?31677

[Jim Luttrall]

Looks like I found my own answer.
Icc report on the product footnote 4: 4 – When the insulation thickness is 3 inches or less, an ignition barrier is not required in attics or crawl spaces. Insulation thicknesses greater than 3 inches require an ignition barrier.

[Claude Lawrenson]

Most building codes appear to offer the same standard, that in concealed spaces that it's acceptable to be left uncovered. I've had it for 25 years in my crawlspaces and it was code approved here in Canada.

[Jerry Peck]

I see the warning on the Dow Styrofoam sheets visible in the attic relating to its combustibility.

Do you have a photo of the warning? What does it say? Any warning on it will take precedence over the code if the warning is more restrictive than the code.

[JeffGHooper]

Do you have a photo of the warning? What does it say? Any warning on it will take precedence over the code if the warning is more restrictive than the code.

And to add to that, if the warning specifically states it is not to be left exposed, it means just that.

[Jerry Peck]

And to add to that, if the warning specifically states it is not to be left exposed, it means just that.

Precisely where I was leading to ... :)

[Jim Luttrall]

My photo of the warning is a bit out of focus but it is not explicit in the verbiage, only says "some" installations "may" require covering. It is combustible but appears to be below the flame spread and smoke allowance in the code. They have a pretty good AHJ where this was built so I am guessing they came to the same concluding I did in reading the code approval document.

[Jerry Peck]

My photo of the warning is a bit out of focus but it is not explicit in the verbiage, only says "some" installations "may" require covering.

Those are key words.

I found the installation instructions here: http://msdssearch.dow.com/PublishedLiteratureDOWCOM/dh_07a1/0901b803807a15b3.pdf?filepath=styrofoam/pdfs/noreg/179-07585.pd&fromPage=GetDoc

This is likely what the warning said:
•CAUTION: This product is combustible and shall only be used as specified by the local building code with respect to flame spread classification and to the use of a suitable thermal barrier. For more information, consult MSDS, call Dow at 1-866-583-BLUE (2583) or contact your local building inspector. In an emergency, call 1-989-636-4400. Building and/or construction practices unrelated to building materials could greatly affect moisture and the potential for mold formation.No material supplier including Dow can give assurance that mold will not develop in any specific system.

The installation instructions also state:
• Attics
- Use without a protective thermal barrier or ignition barrier on the interior of
the building, including (but not limited to) knee and gable end walls
- Attic space may be unventilated or ventilated

Based on the installation instructions and the code, looks like no ignition or thermal barrier is required, but that's why the wording of the warning/caution labels are critical to determine its allowed use.

[CHARLIE VAN FLEET]

guys

I find this in attics and basements and crawl spaces, all the time. I write it up because of manufactures instructions.

cvf

[Jerry Peck]

guys

I find this in attics and basements and crawl spaces, all the time. I write it up because of manufactures instructions.

cvf

That's the type of warning that Jeff and I were expecting Jim come and say was on the Dow Styrofoam sheathing.

Those warnings (on the facings) specifically state not to leave it exposed - EVERYONE - should write that up when they see it (if they can "see it", then it has been "left exposed", which is what it says not to do.

[JeffGHooper]

That's the type of warning that Jeff and I were expecting Jim come and say was on the Dow Styrofoam sheathing.

Those warnings (on the facings) specifically state not to leave it exposed - EVERYONE - should write that up when they see it (if they can "see it", then it has been "left exposed", which is what it says not to do.

Always photograph the "Warning" to include in your report so there is no question as to the validity of your claim. I also use the words "Fire Hazard" and state it must be installed with the facing in direct contact with building materials.

[Jerry Peck]

Always photograph the "Warning" to include in your report so there is no question as to the validity of your claim.

... ALWAYS ... I agree ... always take as good a photo as possible and, yes, it goes in the report.

Some don't like putting in photos, some limit the number of photos they include, others (a few others) don't mind including a photo of basically anything worth taking a photo of (if it is worth taking the photo, it is worth sharing the photo, and it is worth commenting on what is in the photo - as the old saying goes "a photo is worth a thousand words", a photo and a few words can show more than one could try to describe.


I also use the words "Fire Hazard" and state it must be installed with the facing in direct contact with building materials.

I use the same words in the warning ... and most will have "fire hazard" in there. Yep, in substantial contact with gypsum board or other approved building material (however stated in the warning label).

Some of my reports ended up as 'coffee table books' which were left out on display. Kinda cool to see them there. :)