First, some background:

I'm an Owner-Builder in an ICF home (Durisol), former architect cum lowly residential designer, and a skeptic, to some degree. Besides my home I had designed one other home and one addition way back in ICF's infancy. I've done lots of reading about termites and ICF. One of the primary reasons I chose Durisol was because of its purported termite resistance. I have not been proven wrong on this point, but my overall experience with actually working with it causes me to not make it my first choice in specifying for clients' homes (for reasons not germain to this topic—If anyone wants some unbiased opinions about it, feel free to contact me separately). So...

What I'd like to know is: Does anyone out there in the ICF community know of ANY actual reports of termite damage in ICF structures (in particular below-grade installs)? I have yet to find any in all my reading. I certainly won't find any manufacturers or the trade industry providing this info on their websites, even though they will tell us their recommendations for termite-proofing, and the oft-repeated line that "the foam is not a food source, but still will be burrowed through".

And likely you ICF builders who post here won't want to admit termite damage has been discovered on any of your projects.

But logic tells me that surely there HAVE been reports of termite damage, otherwise why would there be so many strategies manufacturers recommend for preventing said damage?

The reason I am asking is I want some degree of peace of mind on this subject so that I can pass on this peace of mind to my clients who want to build with ICF. AND, this is the ONLY issue which keeps me from being a full-fledged ICF advocate.

One final note: I'm not looking for advocates of particular systems and what they recommend for termite treatment. This info is readily available, even here in this forum. I want to know if termite damage is an actual problem as an aid to assessing the recommended protection strategies.

Thanks in advance

I can guess that this will be a very tougue in cheek series of comments and I will step in and state the obvious. I have no knowledge or reports that EPS or steel or concrete have been added to the "menu de termite" or even "the special of the day". Could a "dessert" type product be attached to an ICF?, I suppose it could and if consumed be confused with the in question"main course". This could only happen, in my opinion, if the menu cannot be read or the dish identified. GR

skia_d
Think about the system for a minute. You pour a concrete slab and then you pour a concrete wall, and then you put a wood roof system on it. How far do you think a termite is going to dig in order to find food? In Florida they will follow a trail of wood up into the house and then eat their way completely through the structure. Termites don't build nests in tyrofoam, they build them in wood or in the ground. I have 8 ICF houses that have been in the ground for five years in heavy termite areas and NO reports of damage.
I have seen ants build nests in foam panels that laid on the ground for 8 months before they were used but that was the only time.
If you are still doubtful, use steel studs and steel trusses or pour a concrete roof and dont give them anythinjg to eat.
Regards,
Joe

If there were any issues on this question at all, then all manufacturers industry wide would be involved in treated foam so to not have any complaints. Such is not the case. GR

Thanks for the responses to date.

FlaICF: surely there MUST be issues, because there are, as I said in the first post, "so many strategies manufacturers recommend for preventing said damage" e.g., Nudura with a concrete inspection band at grade level, Amvic with their tech manual Appendix D, Termites and ICF Construction, etc., etc. WHY would the manufacturers (and codes!) address a non-issue? And why would Polyguard be recommended, among other systems, as a means to keep termites from entering the foam? Why bother with termite-focused specialty products for waterproofing systems if there is no issue at all?

It seems to be generally accepted as fact that termites WILL tunnel through foam, and though the foam is not "on the menu", it is nonetheless a footpath they can take to get to their restaurant. jredburn mentions ant nests in foam laid on the ground, and I saw pictures during my surfing of insect-damaged foam during similar jobsite conditions. So the question still remains, but to put a little more focus on it: if termites will chew through the foam, can enough of the chewing create not just footpaths but 8-lane superhighways? Leaving aside the issue of entry to any food source in the house itself for a moment, can the foam damage be significant enough such that the waterproofing systems are thus compromised due to substrate failure?

I've read quite a number of posts on this forum, and I find it interesting that some of the more vocal ICF advocates have stayed silent on what I believe is a straightforward question. I'm serious when I say that this is the one issue hanging out there that still prevents me from being a full-fledged advocate myself. That's why I'm trying to get some straight talk. Shall I assume then that—against the logic I have presented—there is absolutely ZERO concern for termites, especially among the more vocal advocates out there?

Skia_d,

You raise very valid concerns. Termites are definitely an issue for ICF construction. But it's not for the ICF themselves. Termites can and will burrow through foam. They cannot destroy the concrete. However, the termites will attack the any wood structure of your project. The problem with termites and ICF is that the infestation is hidden and very difficult to detect (unless actively looked for). Again, it's not that the termites will destroy the foam, it is that the foam will hide the termites. There are several methods to combat this. First is to borate the foam. Termites do not like borate. However, some have raised concerns that borate in time will weaken EPS foam. How applicable in the "real world" this is I do not know. The second is an inspection band. Basically a strip of foam is removed just above grade from the concrete. You simply look for the termites. If there is wood above grade (just if ICF's used for basement) then just a metal flashing turned downwards to be used as a termite shield.


With regards to substrate failure for waterproofing I guess with enough "swiss cheese" in the foam it could happen. But most waterproofing products could withstand a direct attack (Polyguard comes to mind). Covering the foam with, let's say Permacrete could also be an option but I think expensive.

The borate foam with an inspection band makes the most sense to me.

SKD,
You are correct in assuming that the pathway __could__ be created for termites to travel. They still require food and moisture to eat and propagate and will follow that. If that is not available then the propensity for a problem is virtually eliminated. I would ask an exterminator's opinion.
There are recommended procedures for using ICF in termite country just as ther are requirements for conventional constuction. There are best building practices to be followed. It still comes to the the facts that structures in termite country such as FL must have, by code and inspection compliance, must have termite barriers, ground poisoning, chemical barriers, etc.
It is recommended at least a 6" separation exist from surrounding grade elevation to the base icf course. Avoid contact.That speaks to the suggested inspection band.
We have brought icf out of the ground here. The job was designed and spec'd with treatment and moisture barrier. Someone decided that it was OK to do this.
lk2 and Joe are stating good facts, as am I. I maintain that if borate or additives needed to be in foam then all manufacturers would be mandating it so they could sell products in termite country. Attaching products that are termite food to an ICF has the chance to increase potential problems thereby mandating sound construction practices to avoid the problems that could result.
Good common sense and building practices are what count.

Well I wish I could help out with this one but termites are not prevalent in Michigan, even though southern MI is prone to termites. There we don't worry about them either because we have a waterproofing membrane that I'm confident a termite would not chew on, i.e. no food or housing, and all foam from there up is covered by either stucco, hardie plank etc. At this point it would be no different than any type of construction so I don't see the issue. Or the termites.

Dave

skia_d,
Have found many situations yet? I can tell you of one. The job was done by a Homeowner and while applying brick to the ICF at grade, he capped the floor over the ICF and brick with untreated wood. Of course that doesn't meet code and the moisture buildup in the wood attracted termites.

I've been in the ICF industry for 12 years. As a manufacturer's rep. That is the only instance I've every heard of. I believe that the rumors were started in '98 when ICF started to get a foothold in the basement markets in the Midwest. ICF's were being strongly promoted by the NRMCA and ICFA at the time. Two or three rivals appeared at that time; poured wall contractors, the wood industry, and the pest treatment industry. I am convienced that the termite infestation rumors started there. Call me a conspiracy nut, if you will. Then the EFIS (Exterior Insulation and Finish Systems) law suites started. Bad installations let water into the wood substrates. Termites got to the wood through the foam, so it must be the foam causing it, right? This just added fuel to the fire and locked foam restrictions into the Southern building codes. By the way Georgia is finding that Borate doesn't work, as most ICF manufacturers have been saying for years.

The ICF manufacturers reacted in self defense, at first poo-poo the idea, but as ready mix suppliers, builders and code officials took on the idea, ICF'ers began to react with remedies to overcome the objections thery were getting in the field. Manufacturers had long meetings inside the ICFA and developed the "tell the whole story" response you see in Installation Manuals today.

Why on earth would all these construction people start such a nasty rumor? Profits. If ICF's were to take a signifigant share of the market and large amounts of wood were no longer needed for residential construction, the wood industry would loose, builders would need to re-learn how to build, the pest industry would have less applications and the poured wall contractors would loose their strangle hold on local markets, because concrete forming wouldn't require a large capital investment. Ready Mix suppliers began to feel the heat from the wall guys that bought thousands of yards of concrete each year and so they stayed mum or jumped on the bandwagon with both feet.

Think about, the wood construction industry, it's been around since 1851. That's per-Civil War. It is a strong force. The concrete forming industry is based on selling a few really expensive system with trucks, storage, cleaning and replacement costs all at stake. If homes are built with products that can't be eaten by bugs, the pest control industry takes a big hit. So with these powerful industrial group promoting the anti-ICF movement, it is easy to convience people like builders, tradesmen, lumber distributors, architects and even code officials, that don't want to change anyway, that ICF's are bad. Termites/insect are their "scariest" story that the "masses" understood and the hardest to defy.

The best test is, next time you hear a rumor, dig a little deeper. Where did it come from? Does that person/company have anything to loose if ICF's grow. Or is that person just passing along something they heard. Do they have specific examples that they can point to? Good luck in your hunt. I don't think you'll find much.

PS - A Bituthane barrier system that fully coats the below grade ICF application, over the tops of the footing, will stop termites. Termites don't like asphalt, that's what biututhane is. As you reach grade cover all foam with a cementitious coating that insect can't get through. Then as code requires, keep all wood sidings 8" to 10" off the ground. And you'll have a good shield.

Nope, haven't heard of anything else. And your situation goes to the point others made about common/good sense building practices. Also, I don't think your thoughts are in the conspiracy theory category. It's a "follow the money" thing. That being said, it'd be nice to see more ICF in my neck of the woods. I can count on one finger the builders I know whose ICF experience I trust, but his pricing seems way out of line. There's another builder who really knows his stuff, but alas, for various reasons he's not currently in operation. This makes it rather difficult for me to promote ICF design to clients.

I am considering building with Durisol and would like to know why it isn't your first recommendation to build with. Our lot is wooded and the termite resistance (as well as fire resistance) is foremost in my mind. Glad to hear it scores on that point!
AH

Avis:

See private message I just sent.

I built an ICF in the Charlotte NC area lots of termites here. I used Amvic block below grade on three sides, it's a walkout basement. We wet set the first row, not like that would help with keeping the little critters out but we water proofed with the black goo about 4 inches on the footers then up to grade stucco from there. Plastic tile went over the goo ( forgot brand name ). I did all code stuff with treating bellow basement slab and footer areas for termites. I did stick build the roof we used a pressure treated sill plate. I insulated along the roof line with icenene foam. It must be pretty hot and hopefully dry in between the foam and the wood structure I figured it would not be all that inviting to termites. The floor trusses in the basement are easy to inspect as are the attics. I've been in a year no problems yet, the termite people won't touch the place no skin off my back. Bottom line is life is full of risks keep a good eye on the wood every now and then, a little common sense goes a long way. At least they can't eat the structure holding up the roof. I'll try to keep ICF advocates posted in an honest manner so we can all work together on any potential problems concerning termites. John

Some really good comments here

I believe it was FlaICF that said:  "It still comes to the the facts that structures in termite country such as FL must have, by code and inspection compliance, must have termite barriers, ground poisoning, chemical barriers, etc. "

Here in Texas, code requires the usual normal termite treatment -- for construction with ICF, wood, steel etc. - as far as I can tell code doesn't care.   That said, I have yet to see a single instance here in Texas of termites in an ICF wall or using an ICF wall to get to wood at the top plate or in a window.  I have, however, (as someone else posted above) seen some large ants (I believe they're called wood ants but not sure -- they were not the common in Texas fire variety) make a home in foam that has been left out in the woods for several months or more.  You can do your own test.   I can all but guarantee you won't find any termites in this scenario because there simply isn't any food to consume, moisture or reason to be there.

The basis of this argument is really the same as why you cannot have mold without any biodegradable materials.

I bet your typical conventional homeowner would be shocked if he could see what all is living inside his walls - perhaps roaches etc.  Have you ever torn down a conventional home?

To the author skia_d: 

I admire your desire to design the best for your customers.  Such is not the case with all architects or builders: 
 
From the just released MIT ICF report: 

"In an interview with BUILDER, Ochsendorf conceded that the higher construction costs which builders typically ascribe with energy efficiency continue to be “an honest-to-God barrier” to better building, especially when builders are hardly ever the operators of what they build, so their concerns about long-term post-construction energy efficiency often end at the closing."

I realize this quote is more about energy efficiency as this was the nature of the report.  However, you can carry it forward to insect infiltration, STC, 3 and 4 hour fire ratings, tornado and hurricane resistance etc.  We go to 6 stories load bearing here with 6" ICF and have gone higher in other states.

You won't be wrong in offering your customer the best structure possible with todays technology.   Regards. 

All of the termite issues go back to the EFIS start.  Theey but a layer of foam board over wood framing and covered it with a synthetic  Stucco finish on it.  When they let the foam go below grade (not then correct way to apply) it gave ternites a perfect avenue into the wood framing.  There were a lot of poor instillations of the EFIS finish and it caused the issues to start (foam below grade).  There were many lawsuits over this. 

ICF got caught up in the mess with EFIS.. Not because there were any complaints or issues directly associated with ICF, just the foam below grade.  

If you have any doubt that termites can infiltrate an ICF house, I can dispel them.   We're currently dealing with a termite outbreak in our house in North Carolina.   The termites apparently came up from under the garage slab and have been tunneling through the foam walls for quite some time.   We became aware of it when they chewed a small hole through the Sheetrock that's attached to the ICF wall.   At that point, we called our pest control company (which had treated the house before it was built in 2002 and once since then). They cut away a large rectangle of the Sheetrock to gauge the extent of the damage.    We found an extensive network of termite tunnels in the foam. 

Here's a photo of what the damage looks like.  That's the cut-away Sheetrock visible at the very top of the photo.  You can see that the termites were tunneling right on the surface of the foam.  I assume they either were eating the paper on the inside of the Sheetrock or were just using the foam as a highway to explore for wood.

We don't yet know the full extent of the damage or if the termites reached any wood structural elements of the house.   It seems the only way to find out is to keep ripping off the Sheetrock until we get to the place where the foam is clean and unchewed.

The bottom line is that termites are a risk in ICF homes.  They will readily chew through foam and can be difficult to detect until they've done substantial damage.  Anybody who says otherwise (or dismisses such incidents as "rumors") is -- at best -- misinformed.

DOW Blueguard uses something other than borate. They recommend a 2"-6" inspection strip or a termite flashing/shield.

Alton,

As far as I know, the foam in our house does not contain borates. It's the "Reward" ICF wall system, and the Reward spec sheet I received when our house was built says nothing about borates or termites.

I understand that the current recommendation for ICF walls is to include an inspection strip in the crawlspace. Our house, built in 2002, has no inspection strip. Two questions:
- Does anybody have experience with cutting away the foam in the crawlspace to create an inspection strip in an existing foam wall?
- What can you do to prevent infestation in the part of the wall system that's in the garage, which is on a slab instead of a crawlspace?

I have a roof made of sandwich panels with hard foam interior; it's about 7 years old! My house is old and I rplaced the old roof with the new panels.
Last year, while sleeping in the attic I started hearing nibbling sounds at night and would see small pieces of material all over the place...for a while I wondered what it was...after spraying the panel unions (inside and outside) with regular fly spray I had my answer: TERMITES!Lots of tem...over the winter I didn't see them, but now I started seeing the mess again!

I want to inject boric acid and propylene glycol solution into the foam...does anyone have any suggestions? I plan to get a large bore needle and syringe the liquid into the panels...I can't afford to have an exterminator do the job.
Thanks,
Esperança