Review on MTB Holder Ground Anchor Powder by Joseph Hall

Be careful with them. I wanted to use them for a 14x14 pergola with 6x6 posts. 48 hours for the concrete to set and they were well set, not yielding or squirming. After I cut 6x6's to length they were set up vertically and I started building the pergola. I noticed movement, but found that the movement would stop as soon as I attached the bolts to the joists. That didn't happen. The next morning the entire structure was shifted along with the bent metal and swayed in the wind. I removed the pergola for safety and now have to figure out how to remove the brackets and break up the concrete. Next time I'll put the posts in the ground which in retrospect was 8:20pm as I had already dug the holes for the foundations I should have just put them in the ground.