Commercial building with formaldahide urea foam in the block. Wicking moisture
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30 year old 28,000 sq foot building in Michigan. Climate zone 6B. 12 inch CMU. Wet foundation. Done all we can to remedy that. We are absolutely sure that the foam in the blocks is wicking water up into the CMU. Fair amount of freeze thaw cracking up to the 5th block course. Not just mortar joint cracking, but the actual block. Also hard to keep elastomeric paint on the CMU because the moisture content measured from the outside in the summer is over 15%.
Plenty of ideas. Anybody had experience?
Cut in a series of weep holes?
Retrofit some type of wicks near the bottom course?
Completely remove some blocks and replace with hollow blocks?
Remove the exterior face of some of the blocks, pull out the foam and cover with a vent?
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Replies
Install a capillary break or lower the water level take you pick.
I know you said you have done everything you could for the foundation but I have to ask do you have a working footing drain going to daylight? Might not be possible will not be cheap or easy but it is the right thing to do. Sounds like you have tried all the Band-Aid’s.
Walta
With enough insulation on the exterior and some heat inside, the block wouldn't freeze. Vapor permeable (eg, mineral wool) will allow more drying.
CMUs are pretty porous so the foam may not be the only culprit. UFFI (urea formaldehyde foam) is open cell so it could wick water as well. I agree with Walter and Jon--some combination of better footing drains and exterior insulation are your best bets at this point. Ideally you would slip a capillary break in at the bottom of the wall--sheet metal is a good option--but lifting most of a foundation is not an easy job.
You folks are sure helpful. I am the owner, with some building knowledge. Have a national contractor on site, building it out for Amazon. Also a Sherwin Williams tech rep, a structural engineer, and a great brick mason. Several root causes. Plenty of ideas. We all agree that where we can, we must work on improved drainage. Clay soil so the water seems to perch high, goes away slowly. Last paint job only 7 years ago was poorly done; not back rolled so pin holes let the water get under elastomeric paint. See photos. Will tuck point bad motor joints, remove broken 12" block that are mostly on the section of the building that was unheated for 8 years. Agree we must break capillary action in the foam near ground level. Debate on how to do that well but cost effectively. Is just cutting the mortor joint and through the foam to the inside of the block enough? That would provide a 1/2 inch gap. Need to slip anything in the gap we crated like a wicking material we found online, or pieces of sheet metal or plexiglass? Or some sort of grout or caulk in the cavity? Mortar it shut or leave a small mortar joint weep hole every second, third or fourth block? Again, thanks so much.
The hard part of installing a capillary break is how you can do it. Sound easy, just put a continues layer of sheet metal the entire length of every wall. The question is what holds up the walls and roof while you work on the walls.
Caulking in this wall can be applied to the surface to make it pretty but it can not provide the support this wall needs to remain standing.
Is there room to dig a ditch?
Please post your photos a jpg I could not open them.
As a side note why do you think the richest man on earth chooses to rent and not own?
Walta
Just posted photos.
Thanks, Walta. Yes, Jeff Bezos likes to rent. I would like to sell but here I am. 😂 JPG photos should show up now. We're going to install a capillary break, just deciding how. Open to suggestions. Maybe we grind out 10 lineal feet, skip a few feet for wall strength, then grind out 10 more. Dig out some foam, then Insert metal pieces just between the webs? Or grind through the block webs to the inside face and lay long metal strips? Either way, there is an idea of cutting in a lateral weep hole every 5th block or so. Prefer continuous metal or plastic capillary breaks but not sure how to get them in safely. Afraid to cut through all of the interior block webs. The notion of some sort of caulk was in reference to sealing the capillary breaks at joints... You can see that we are wrestling with affordable technique. None of us has done this on retrofit.
Michael, while crowd-sourcing advice here is a good way to start, I highly recommend engaging a specialist consultant to help you figure out a plan. If Mr. Bezos is your tenant I'm sure you can afford it.
Actually Mr. Bezos pays very low rent. We have a national builder, local structural engineer and a mason involved. They are debating a plan, open to outside suggestions. Not sure what defines a specialist consultant is in this arena. Certainly have tried to find one.
This is a directory: https://iibec.org/membership/search/
One in Michigan: https://www.sme-usa.com/
Two nationally-known, extremely reputable consultants:
https://www.buildingscience.com/
https://www.christine-williamson.com/
It would just be a shame to spend tens of thousands of dollars (or more) based on relatively anonymous and non-accountable feedback when there are people who can tell you exactly what to do and why.
Thanks so much.
Actually one suggestion was after inserting capillary breaks, cut in vertical weep holes one block course below the breaks.....perhaps inserting some type of weep/wicking material to help the process.