Hi everyone, My wife and I are pretty distraught about the situation... we got our occupancy on 9/16, so our house is coming up on 3 years old. We had a builder who is getting ready for retirement and wanted to do as little as possible to get a check. Picking him, and sips, were our only mistake in this whole endeavor. I had to beg him to cover the sips while we got 10-15 inches of rain while they screwed around with the foundation (it’s a stemwall and slab), here in Northern California. He eventually did cover them and most of them didn’t get soaked, laying down, but the did while they stood them up. Enough that the sill plates swelled and they had to rip 1/8 in off them to get them to sit down. Anyway, I did all the air sealing and got a 1.75 blower door, we have a HRV, and the house is pretty tight. He didn’t spray foam the chases (its single story shed roof) and I noticed when the wind blows, it’s smells like bleach / cocaine (go figure) from the outlets and holes in the inside Osb. I’ve had to remove all the trim and air seal the boxes and window sills etc but I’m on top of a hill and it blows a lot. I got it way better, and maybe the smell isn’t as strong, but after 3 heat cycles and 3 winters shouldn’t this smell go away? I did the siding and pulled some off to make sure no leaks, and there are none. I even have the smell where there is no rain hitting. I found some old sip outside and realized the smell is from the foam, not the wood. He did use the crappy green glue , I thought it was that but it’s definitely the foam. I did a home air test about 18 months ago in a confined half bath where it was really bad and the results weren’t too bad. Not enough to worry us and my 14 foot ceiling house is probably way less concentrated than that little room. And the smell is less. I think the sips were from a broker, and came from premier. What could be causing this smell and will it go away? I am throwing money at this property left and right and am having a hard time doin that not knowing if I want to live here my whole life and I’m raising a 2 year old and one more coming. Any advice would be much appreciated.

A tight home would prolong the off gassing process. As weather allows open windows and circulating fans might help. You may want to review your building envelope and make sure it has a way of drying to the less humid side. You don't want to be trapping moisture in the wall or have improper flashing etc. that allows water entry.

In the meantime there are other items you can use to help mask the odor - baking soda, essential oil diffusers, potpourri.

I also wanted to add that the tester didn’t show much in terms of VOC, but moderate in formadehyde. Maybe the glue in the osp leached into the foam?

Is your SIP manufactured with EPS foam or polyurethane foam?

What type of foam did they use, EPS, polyiso, polyurethane, other? I would guess that your panels are manufactured with polyurethane foam which is known for its unpleasant smell. It often produces a chemical like smell.

See what can be done about going back and using minimally expanding foam on the chases to fully seal them.

Have an air quality test done.

See if you can adjust the throughput of your HRV for a greater number of air exchanges per-hour for a while and see if that helps offset this.

Also check the humidity indoors.

I'd also contact the SIP manufacturer and have them recommend you to another trusted SIP builder in your area and have them come out and inspect.

Sounds like OSB offgassing or if the foam core id polyu or polyiso it is off gassing, it will stop is about 10 years