Foam Board Insulation

[Tom King]

I was poking around another condo and came across some foam board insulation in the basement (it was behind some fiberglass) and up in the attic.

It would seem covering it would be tricky so maybe removal is better but What do you think you would say?

Here are some pics...

The fist is in the basement, the second is in the attic (but you need to tilt your head left to see it right...)

[Eric Barker]

I'm going to be against the flow on this but my thought would be that it looks like a nice job.

[Tom King]

I'm going to be against the flow on this but my thought would be that it looks like a nice job.



I'm all for dissenting opinions. For me, as soon as I see it in the basement I feel like it needs to be called out. (Note: Condo is from 1980)

The attic was less concerning to me but I would like to hear more about your take.

[Bruce Ramsey]

Just don't have open flames in the basement or attic near the foam. :D

If the house is on fire, why are you rummaging around in the attic or basement breathing the offgas of the foam? Get the heck out of the burning building!

[Tom King]

Just don't have open flames in the basement or attic near the foam. :D

If the house is on fire, why are you rummaging around in the attic or basement breathing the offgas of the foam? Get the heck out of the burning building!



I'm told gasoline fumes are bad for me too but I kind of like the smell...

[Scott Patterson]

I'm all for dissenting opinions. For me, as soon as I see it in the basement I feel like it needs to be called out. (Note: Condo is from 1980)

The attic was less concerning to me but I would like to hear more about your take.

What is wrong with it in the basement?

[Tom King]

What is wrong with it in the basement?

Whenever I see it, I call it out whether it is in a basement or garage.

What's wrong with it is the problems associated with it when it catches on fire as you know already.

My question is why is it OK in a basement?

[Scott Patterson]

Whenever I see it, I call it out whether it is in a basement or garage.

What's wrong with it is the problems associated with it when it catches on fire as you know already.

My question is why is it OK in a basement?

I know of no prohibition against it. I see EPS foam all the time in new construction basements with formed concrete walls.

[Tom King]

I know of no prohibition against it. I see EPS foam all the time in new construction basements with formed concrete walls.

What happens if it catches on fire? I know it can be hard to ignite but once it does the smoke and fumes can be big trouble.

In Rhode Island we had a nightclub fire where exposed insulation, once on fire, burned very fast and a lot of lives were lost.

I'd have to go diggin but isn't flammable material like this suppose to be behind some fire rated material like either 3/8" or 1/2" drywall?

[Tom King]

Do foam insulation boards installed on the interior require fire protection?
All foams require thermal protection equal to ½-inch of gypsum wall board when installed on the interior of a building, including a crawlspace. The only exception is Celotex ThermaxÒ polyisocyanurate, which may be installed without a thermal barrier where approved by the local building code official.


From NACHI at Residential Foundation Insulation - InterNACHI (http://www.nachi.org/foundationinsulation.htm)

[Scott Patterson]

In my area the AHJ's allow EPS to be exposed in unfinished basements, crawlspaces and attics. Basically in non-habitable areas of a home. I think this is what DOW says about it's blue EPS board.

[Eric Barker]

This same concern has been expressed with exposed paper vapor retarders and their tendency to easily ignite. As soon as someone moves into the home it's going to be loaded with combustible possessions (manufactured with stuff that emits all kinds of toxins when burned). If you've seen any videos on staged fires in furnished residential settings then you know that an unsurvivable flash-over can occur in as little as 40 seconds. So it's irrelevant to me if there's exposed paper or form building products present.

[Jerry Peck]

Foam plastic needs a thermal barrier protecting it, there are a few exceptions as to where the foam plastic is located: (bold and underlining are mine) - R314.5.3 Attics. The thermal barrier specified in Section 314.4 is not required where attic access is required by Section R807.1 and where the space is entered only for service of utilities and when the foam plastic insulation is protected against ignition using one of the following ignition barrier materials:

- - 1. 1.5-inch-thick (38 mm) mineral fiber insulation;
- - 2. 0.25-inch-thick (6.4 mm) wood structural panels;
- - 3. 0.375-inch (9.5 mm) particleboard;
- - 4. 0.25-inch (6.4 mm) hardboard;
- - 5. 0.375-inch (9.5 mm) gypsum board; or
- - 6. Corrosion-resistant steel having a base metal thickness of 0.016 inch (0.406 mm).
- The above ignition barrier is not required where the foam plastic insulation has been tested in accordance with Section R314.6.


- R314.5.4 Crawl spaces. The thermal barrier specified in Section R314.4 is not required where crawlspace access is required by Section R408.3 and where entry is made only for service of utilities and the foam plastic insulation is protected against ignition using one of the following ignition barrier materials:
- - 1. 1.5-inch-thick (38 mm) mineral fiber insulation;
- - 2. 0.25-inch-thick (6.4 mm) wood structural panels;
- - 3. 0.375-inch (9.5 mm) particleboard;
- - 4. 0.25-inch (6.4 mm) hardboard;
- - 5. 0.375-inch (9.5 mm) gypsum board; or
- - 6. Corrosion-resistant steel having a base metal thickness of 0.016 inch (0.41 mm).
- The above ignition barrier is not required where the foam plastic insulation has been tested in accordance with Section R314.6.

A basement does not have even those exceptions.

[Tom King]

F- The above ignition barrier is not required where the foam plastic insulation has been tested in accordance with Section R314.6.





Great information, so it would seem a barrier is required except for material tested under R314.6 only, when the heck would I know that by looking at it?

So, I'll stick with see it, call it.