I had the chance to do a very unscientific comparison of three types of construction adhesives today. All were bonding SPF lumber to concrete. I demoed the walls to switch to pressure treated bottom plates. The three were, in order of holding power:

Loctite PL Concrete Polyurethane
Liquid Nails Heavy Duty
Liquid Nails Polyurethane

All had cured for a couple weeks on the same slab which was cleaned with white vinegar and compressed air.

The loctite polyurethane was so tenacious it split the bottom plates into small pieces and required a combination of sawzall, 10lb sledge and a 4’ crow bar and a lot of grunting and frustration. It had to be chiseled off the slab.

The liquid nails heavy duty cost about a third as much. It took a few solid blows of a 3lb sledge on each side to loosen up and then came off intact. It appeared to still be curing in some spots.

The liquid nails polyurethane, same price as loctite, oddly did not seem to adhere to the concrete. The whole bottom plate came up fairly easily with the crow bar and it peeled off the slab with minimal pressure from a paint scraper, almost like latex caulk. Hopefully this is helpful for folks in the future. If you are gluing interior walls down, I’d say the loctite polyurethane was every bit as effective as mechanical fasteners without the risk of puncturing radiant floor pex. I cannot comment on the longevity.

Cheers, Zane