Saw a weird glue failure on a job site last Tuesday

I was doing a lvt install in a new build outside Tulsa and noticed the subfloor in one room had this bubbling under the glue. The GC said another crew laid down carpet glue a week ago and it looked like it never set right. I touched it with my finger and it was still tacky like day one. We had to scrape off a 200 square foot section before we could even start. Turns out the temp dropped to 45 that night and the glue didn't cure properly. The guy who did it didn't check the manufacturer spec on the bucket. Anyone else run into this kind of glue failure on a cold slab?

3 comments

3 Comments

kim_west2mo ago

Geez, I gotta push back on that a little. I mean, sure, the manufacturer specs are important, but sometimes the job site just doesn't cooperate. You can't always control the temperature perfectly, especially on a big new build where the heating isn't running yet. The GC should have caught that the subfloor was too cold before the glue went down, not blamed the guy who just followed the standard procedure. And honestly, if the glue is that finicky about 45 degrees, maybe the product itself isn't tough enough for real world conditions. We've all glued stuff in borderline weather and had it hold fine for years, so maybe it's just a bad batch or the other crew mixed it wrong.

sullivan.finley1mo ago

Wow, really have to jump in on this one. @kim_west you mentioned the product being too finicky at 45 degrees but here's the thing nobody's brought up yet - that glue might have been old stock that was stored in an unheated warehouse all winter. I've seen batches of adhesive that froze and thawed multiple times before they even got to the job. The chemistry goes bad and no amount of checking slab temp will fix it. That sticky mess you found? Could have been doomed from the moment it left the supplier's shelf. Always worth asking the distributor if the glue sat through a cold snap before you use it.

richard_dixon2mo ago

Been there more times than I care to count. You gotta check the manufacturer's instructions for the minimum temperature, not just air temp but slab temp too. A cold slab can stay tacky for days and cause delamination down the road. Next time use a infrared thermometer on the concrete before you even open the bucket. Also helps to store the adhesive in a warm room overnight before you use it.