Fun with the hammer drill. Drilling every 2' and 2"-3" from the corners, I pounded in 75 of these tough pins. Only bent one of them and that's because I didn't drill deep enough.

Definitely a great purchase. They worked perfectly. I just used a masonry drill bit with a regular drill and went into the mortar. I used these and adhesive for a good seal. I really love this site! It is informative and easy to navigate. You cannot beat this company for crawl space supplies!

I've used them to attach the 20mil membrane to fondations sprayed with polyurethane and to my surprise, they worked great. Because the surface is so irregular, I would have needed twice as much as I thought. Couldn't find something as good at the store.

The cement block in my crawl space was a little damp making the double stick tape not the best option. So after speaking with Larry he recommended going with the pins to secure the 12 mil and then the polyurethane caulk just above it to make a nice waterproof seal. As usual, Larry was right on the money and it worked great. I recommend getting one more bag of pins (or a tube of poly) than you think. It's better than having to reorder, pay shipping.and more importantly, having to stop your progress.

Easy to install once hole is drilled, just lightly tap in or they will bend over and snap off