We just found mould in the basement our new ICF house (not yet occupied). We've ripped out 20' of drywall so far.

The cause seems to be the asphalt driveway we installed for our neighbour (we damaged theirs during construction -- long story). The driveway was run right up to the edge of our house, however, despite the builder's warning to stay away from the ICF.

It certainly looks (completely obvious to us, anyway) as though the asphalt melted through the water barrier and enough of the ICF to allow water to follow the seams through the concrete and into our basement.

The driveway guys are saying their hot asphalt isn't hot enough to melt through and the thousands in resulting damages aren't their fault. They, in fact, say they've put 'thousands' of driveways beside styrofoam without a problem. (Of course it's not the styrofoam that's the problem, it's the moisture barrier, but anyway).

Does anyone have any experience with these two materials coming together? Is it, for example, common knowledge that one can't put asphalt beside ICFs?

In case it's important: These are Nudura ICFs with 2.5" of insulation and Nudura's own water barrier.

Thanks, Colin.

Asphalt is not only hot, but petroleum based. Petroleum eats EPS. To demonstrate, take a scrap block and pour gas or concrete sealer or anything petroleum based on it and see what happens.

I agree.  I have seen petroleum products dissolve EPS.

I'm not sure if a chemical reaction is involved but a closer look this evening confirms heat was at least the primary factor. They melted through the hard plastic dimple wall too! (It was an extra protection for the thin membrane against a sharp stop piercing it, etc.)

Nudura has now confirmed "of course it would melt it" as well. Hope the driveway guys agree!

Where are you located?

We're in Toronto.

cfoster,

Asphalt when delivered is close to 350 degrees F. It will definitely melt EPS and the membrane. Unfortunately, it seems many asphalt driveway contractors do not know anything except how to make asphalt look pretty! And details are rarely passed down to the crew! It's actually a wonder that they did not damage your walls with the roller!!!
I sure hope they were not paid yet. Take lots of pictures for your attorney and the judge. Sometimes, a letter from your attorney will prompt the contractor to repair the damage, especially if the contractor is given a specific date to make restitution by, and if not you will hire a contractor to repair it and take the cost off his asphalt bill. If the asphalt contractor ignores it just go ahead and hire someone to repair it. If he threatens to sue just say "Go ahead. I can't wait to show the court what you did to my walls!"
Make sure to include your foundation contractor in the letter and your home builder; especially if he was in charge of the construction.
DO NOT PAY ANY OF THEM UNTIL THE PROBLEM IS REPAIRED!!!!!
Best of luck and keep us posted of the outcome.
Rich

Hi Rich,

Driveway guys were paid 5-6 weeks ago when they did the job. (The water was seeping behind the drywall for that long.) We gave them the option of coming down to see it, but they had no interest. (After much berating they agreed to come "Friday or maybe Saturday" but we couldn't wait. We have to complete the build (we move in in 17 days) so the repairs have now begun in earnest. We have lots of pictures, video and the heavy plastic dimple wall they melted through before getting to the water barrier and ICF block.

I called an engineer who's working on the project and he just said "You don't need an engineer to tell you that's melted. Melted, is melted. The asphalt was actually paved INTO the block so what else would do that?"

It will be a year or two before we get our day in small claims court (assuming they don't step up). They were really great guys up until this point. They had broken a window on another part of the job and immediately handed over the cash for the repair. But now that we're into 4-figures of repairs...

I also called a mould-cleanup company and they said there was no need for their services. They said since the interior walls are styrofoam there was no special cleanup involved. The mould can't live on styrofoam, just the drywall paper, so the mould we see is just on the surface (rubbed off from the drywall). We just need to wash the mould off and that should be fine. If I wanted to be "super safe" (and who doesn't when it comes to mould) they said to paint the styrofoam, which would seal in any spores that might remain. (Hooray for ICFs!)

-Colin.

The dangers of mold are grossly over blown. Unless someone in the house is hyper allergenic to mold spores go with the recommendations of the mold cleanup folks. We all live w/ mold spores everyday, everywhere. Only in grossly serious cases of mold infestation is there a danger of toxic mold being present.

Even in the aftermath of Hurricane Katrina in New Orleans doctors were cautioning about being excessively concerned about clean up, and personal protection. This was in cases where the walls were black from floor to ceiling with mold.

Wash it off with bleach, cover it up with clean drywall, and you'll be OK.

Yes, I totally agree there is alot of misinformation out there regarding mold. I just got thru a mold problem in my own home. Entire wall and all flooring had to be replaced (the open wall showed very clearly why fiberglass should not be used for insulation in a home)!

The mold "experts" (who are certified remediators) told me that household bleach will NOT kill mold spores. I remember from college days in Microbiology and from working in a county health dept. that the experts are correct. They used a product specifically made for killing mold spores.

Also, painting the styrofoam will NOT seal in the mold spores, they will love the environment and will keep growing (water based paint - yum! - new sheetrock - yummier!" Possibly a sealer such as "Kilz" or Bin Sealer will contain the spores.

Do you have a Better Business Bureau in your city or something like it? If so, give them a complaint regarding your dilema. By any chance do you have insurance info on the asphalt contractor? You could probably get it with a call to the contractors office - have someone else call.  Call the insurance company (not the agent) and discuss the problem with them.

That brings up another possible thread - getting insurance certificates from your contractors naming you as additional insured. Anyone building anything should require this.

With the media loving stuff like this and with energy efficiency on the forefront of construction these days - call your favorite local TV station and have them do a story on it! Around here (NC) that is done all the time. I can see the headline "Hot asphalt ruins energy savings, story at 6 pm"!!!

Hope the rest of the home turns out to be all you hoped for!

Rich

From the CDC website:

http://www.cdc.gov/mold/faqs.htm

"Mold growth can be removed from hard surfaces with commercial products, soap and water, or a bleach solution of no more than 1 cup of bleach in 1 gallon of water."

Article about some research at National Jewish Medical and Research Center. They found that bleach not only killed the mold spores but made the killed spores less allergenic.

http://www.medicalnewstoday.com/articles/31076.php

"The researchers grew the common fungus Aspergillus fumigatus on building materials for two weeks, and then sprayed some with a dilute household bleach solution (1:16 bleach to water), some with Tilex� Mold & Mildew Remover, a cleaning product containing both bleach and detergent, and others only with distilled water as a control. They then compared the viability and the allergenicity of the treated and untreated mold.

The researchers found that the use of the dilute bleach solution killed the A. fumigatus spores. When viewed using an electron microscope, the treated fungal spores appeared smaller, and lacked the surface structures present on healthy spores. In addition, surface allergens were no longer detected by ELISA antibody-binding assays, suggesting that the spores were no longer allergenic."

In the interest of disclosure the research was sponsored by Clorox.

On the other hand you will find websites of those who make a living fighting mold saying that bleach doesn't work.

The only permanent solution is clean off the mold and prevent the recurrence of the heat and humidity that allowed the mold to grow in the first place.

Here's an EPA page on dealing with mold:
http://www.epa.gov/mold/table2.html

Summary: removing mold is fine, but useless without moisture control. If there isn't excessive moisture, mold won't grow.

The mold company I called also mentioned that any chemical treatment of a surface designed to prevent mold is only good for about 6 months. After that, if moisture is still present, the mold will return. The exterior wall is now re-sealed so presumably once we get the HRV turned on and circulating air in the house to control humidity all will be fine.

The house is coming together really well despite this little crisis. Thanks everyone!

If the basement is closed in now, the weather is warm, and you can feel humidity in the basement you really need to get some air flowing through there now. Use a temporary fan or blower of some sort. I didn't do that for my crawl space and mold grew all over the place in there. At the very least use a fair sized dehumidifier to keep the humidity down.

Waiting until the HRV is turned on may be too late.

dmaceld & cfoster

That's good info for mold - thank you. I bet the remediation co. says just bleach won't kill is so they can charge more for the "special" stuff! Good thing for me is the insurance co. paid for everything.

Rich