Spray Foam unintended consequences?

[thmcginn]

Hello All,

Has anyone ran into the law of unintended consequences with regards to spray foam insulation? While it has its merits, I'm concerned about encapsulating the buildings infrastructure systems, in foam. What are the negatives; if you have a plumbing leak, need to pull a few new circuits, or repair structural members because of infiltration or infestation problems? How does it effect servicing, maintenance, or alterations? What are the long term, if any, effects on the buildings overall performance?

Tim McGinn
T H McGinn & Co., Inc
Waterford, VA

[Riversong]

Re: Spray Foam unintended consequences?

Has anyone ran into the law of unintended consequences with regards to spray foam insulation?

You've hit the nail on the head. All technologies have unintended consequences (as you noted, it's a LAW).

See my comment #10 on http://forums.jlconline.com/forums/s...ad.php?t=48128.

It is to "skirt" that law that I prefer low-tech materials and methods and building forgiving structures and thermal envelopes.

It'll be interesting to see what experiences and perspectives get shared here.

[Dancing Dan]

Re: Spray Foam unintended consequences?

Robert - you can link directly to a post - click on the post # in the upper right and it comes up as its own url.

I don't have any direct experience with unintended consequences - we haven't had the chance to tear into the few projects we've done foam on. Mark Parlee has posted some shots of what seem like the consequences of poorly-installed foam, but that is a slightly different issue.

[Pete Engle]

Re: Spray Foam unintended consequences?

I have pulled wires through walls with low-density foam (Icynene) in my own house. It was a piece of cake. It was relatively easy to fish the snake down through the foam & grab it at the other end. Pull wires as usual - hardly any more resistance than an open wall. Once the wiring was done, I touched up the bottom and top of the new "chase" with spray foam. All done.

I have also pulled all of the foam out of a wall cavity for inspection purposes. The low density foam pulls out pretty easily, and leaves the cavity surprisingly clean. high density foam is a whole 'nuther animal. That would be a bear to do retrofits in.

[dgbldr]

Re: Spray Foam unintended consequences?

Yes, there are issues but a little planning goes a long way in dealing with most. As noted, low density foam is not an issue, so I'm talking high density.

First, it's a good idea to keep plumbing out of outside walls (I'm in a freezing climate) so no plumbing in foam.

You can run the romex in conduit, so you can service it. You can also run additional conduit for future needs, including cable, network and other wiring. Again, except for receptacles, try to avoid running anything electrical in outside walls if possible.

Properly applied foam should cure as a solid block (per cavity) without voids and fill the cavity. The foam is closed cell, so very little chance of infiltration. If you are in an area with bugs that like to eat the foam, that's a problem :)

[Mark Parlee]

Re: Spray Foam unintended consequences?

DG

I have never seen bugs infiltrate the high density foam and the foam that I have seen the bugs in is usually wet. Somehow the combination of wet and foam seems to be the formula for bug infestation. Fix the leaks and detail flashings to prevent this moisture and the system does seem to stay intact.

I have had one instance of termites in foam that was kind of strange to me.
I had a bunch of leftover 2' x8' rippers of the blue dow foam (polystyrene) stored in my mom's basement stacked against the outside wall. These were in the horizontal position standing on edge; we fond them infested with termites in approximately three months of storage. I realize there is no food value and this particular foam material does not allow moisture to wet anything accept the surface. I have never come up with an answer for this even a hypothesis.
Pete, what say you?
I have looked at a friend of mine's home that had below grade foam with no break all the way up two stories. they had a termite problem that started in the foam below grade and the termites went up the foam and int the wall at the top and started eating down. he also had a moisture infiltration problem in the foam so it seemed to be one component of this problem.
The foam was the foil backed (polyisocyanurate)and this is what I see most often infested with insects.

[Unforgiven]

Re: Spray Foam unintended consequences?

I, too have seen bug infested foam. The infestations would seem difficult to treat, though, as most pesticides are waterborne or vaporous, and closed-cell foams retard the infiltration of both. It's the perfect environment for a termite highway. I wouldn' be surprised if we soon find spray foams with pesticides in the formula.
In a somewhat related story my company worked on an estate with many highly detailed entry gates, all adorned with foam architectural elements (bands, moldings, caps, and finials; you name it) covered in acrylic cement and precolored stucco. Before the last one was done the first ones were home to some pretty mean colonies of bees (or wasps maybe?, it's been 10 years). They ended up tearing some of them down and rebuilding them with masonry instead of foam.

I'm currently working on a project where birds got into the icynene and are nesting. Not sure how we're going to get them out.

[Dancing Dan]

Re: Spray Foam unintended consequences?

Here's a shot of ant-infested blue board a friend sent me recently.

[Riversong]

Re: Spray Foam unintended consequences?

Here's a shot of ant-infested blue board a friend sent me recently.

Yup, those are carpenter ants. Are they union or freelance?

Puts the lie to the oft-repeated claim from foam manufacturers and installers that "it has no food value so it will not attract insects".

[Riversong]

Re: Spray Foam unintended consequences?

I have looked at a friend of mine's home that had below grade foam with no break all the way up two stories. they had a termite problem that started in the foam below grade and the termites went up the foam and int the wall at the top and started eating down... The foam was the foil backed polyisocyanurate.

Shows that the thin foil facing serves as an effective insect barrier. Too bad he didn't put foil tape at the top and bottom edges.

[Dick Seibert]

Re: Spray Foam unintended consequences?

Here's what code has to say, this is CBC/IBC but I assume the residential code is similar.

[dgbldr]

Re: Spray Foam unintended consequences?

Dick,

The section you outlined in yellow has exception #1 that says foam is OK if you use steel or PT framing. I don't get it. What does the framing material have to do with termites eating the foam?

[Dick Seibert]

Re: Spray Foam unintended consequences?

DG:

Code is a minimum for health and safety, it's okay for the critters to eat the insulation away, just not the structure that can fall down and hurt someone.

Now that being said, don't ask me how many states are adopting an energy code, and California even a green building code (that conflicts with it's energy and building codes), I've talked to several building inspectors who feel that we are plunging headlong into fascism through the building codes, two have quit their jobs in disgust, of course I knew a cop who quit in disgust when we imposed the smoking bans 10 years ago, saying he could never enforce such a fascist law.

[Martin Holladay]

Re: Spray Foam unintended consequences?

Goodness! Fascism!

I always wondered whether building codes were a left-wing conspiracy or a right-wing conspiracy. I'm glad someone is able to confirm that the source of these regulations turns out to be the extreme right.

Who knew?

[Dick Seibert]

Re: Spray Foam unintended consequences?

Martin:

There is a huge dispute going on within the code community as to how far they can/should go carrying out their mandate, with the adoption of the I Codes it is now evident that the process has been taken over by the manufacturers not only getting products approved but actually mandating them. This really hit the fan last September when the fire sprinkler industry literally bought the sprinkler mandate by paying the expenses of delegates to vote them in, many states are now banning the mandate, Governor Perry of Texas signed legislation Friday banning the implementation of the sprinkler mandate.

We were told several years ago that the intent of the I Codes was to bring the entire country into structural compliance with UBC type codes, not only was the midwestern portion of the country at risk for another New Madrid type earthquake, but the northeastern seaboard was at risk for another Big One, the hurricane of 1938 that was the worst disaster to ever hit the United States, instead of real life-safety provisions to protect the country from earthquake, hurricane, and tornado damage we are getting fire sprinklers, energy, and in California's case even green building codes. San Francisco passed an ordinance requiring composting or people will be fined, I now see people demanding the banning of garbage disposals so everyone has to compost, Fascism?

Know your garbage
So the mayor and supervisors have agreed to fine us for failing to properly sort our garbage. Which of them, or their staffs, can correctly answer the following:

1. Cottage cheese container. Is this waxed cardboard for the green box, or does it go in the black box?

2. Yogurt container. Same issue.

3. Butcher's freezer paper. Green, blue or black box?

4. Plastic container from supermarket meat and poultry - and the soaking wet nappy liners?

Which of them is older than 75 and confused about simple things, much less this?

DEBBY NOSOWSKY
San Francisco

Dump the disposals
If San Francisco is going to have the toughest composting law in the United States, then we should further this cause by prohibiting the installation of kitchen garbage disposals in new or renovated homes and apartments.

All the food (coffee grounds, veggies, etc.) ground up in disposals could be composted.

BOBBI WILTSEK
San Francisco ¹

¹ http://www.sfgate.com/cgi-bin/articl...ED7K1868O1.DTL