Grailcoat on SIPs Repairs
I have a client with a failing Grailcoat job in NC. The house is framed with 6″ Insulspan walls. The Grailcoating apparently cracked, let in water, and there are numerous soft spots in the outer layer of the SIP’s OSB.
1. Has anybody had a Grailcoat job fixed?
2. Did the fix work, and what did it look like?
3. What is the proper way to repair a SIPs panel?
Thanks for any help.
GBA Detail Library
A collection of one thousand construction details organized by climate and house part
Replies
John,
I'm not familiar with GrailCoat, so I looked it up. It appears to be a brand name for a type of synthetic stucco (or, to describe it more accurately, a type of stucco with polymer additives). If anyone has more information on GrailCoat, please share it.
Stucco without a drainage gap is very risky -- especially over OSB. I have discussed the issue at length in this blog: To Install Stucco Right, Include an Air Gap.
Concerning repairs to rotting SIP walls: many builders in Juneau, Alaska, have experience doing such repairs, since Juneau had an epidemic of SIP failures. Here's what I wrote about repairing rotten SIP walls in my September 2003 article on the topic in Energy Design Update:
"The best way to repair SIP wall rot depends on the extent of the damage. “With some of these buildings, the only thing we can do is tear the wall panels out and rebuild the walls,” says [John] Cooper [a Juneau engineer]. Daniel Ulery [vice president of Four Eagles Construction in Juneau] usually replaces damaged
SIPs with stud walls. “Where the walls are rotten, we either replace the SIPs with 2x6 framing, or if there is only a small amount of damage we can cut the skin out and rebond new pressure-treated plywood to the foam,” says Ulery. Cooper has overseen repairs using new SIPs, although that strategy leaves him crossing his fingers. “We think we have licked the problems, but we can’t be sure,” he says."
Thanks for the reply, Martin. I also think it's chancy trying to repair the Grailcoat, It seems to be a flawed system to begin with.
I was hoping to hear from someone who has done the "rebonding" repair on a SIPs panel.
Thanks again.
I would recommend going back to Insulspan and talking to their engineers. They may be able to make recommendations on how to repair their product. If it is anything other than small spots I would want an "engineered" solution anyway for liability reasons (not to mention peace of mind).
I used GrailCoat on my ICF house. It failed right away. They blamed it on manufacturers. They had another company mixing the "secret formula". Long story short I had to sue them and did not get near the amount It would take to fix the problem, I painted over it with elstameric paint and that stopped the leaks. It has been 8 years and I am starting to see the Grailcoat separate from the ICF. I was searching on the best way to repair the problem when I came upon your post. I built my house in 2003. I wanted to remove it back then and replace it with something that has been used for a long time and has a good reputation. I hope they aren't in business anymore. I am going to try patching the few places I have puckering and cracking. ( It is only on the East wall.) If anybody has repaired this crap on ICF please respond. Right now I plan on getting a smooth surface patching it with a good caulk and paint it. It is a small area by the way.