[SSLance]

Yeah, I went back and forth on that over and over again reading all of the experts on the internet saying it shouldn't be done while I was researching the lift install too. The more I looked and read, the more I realized that those saying you shouldn't span an expansion joint with the base of a two post lift were the same types that probably wouldn't ever even attempt to install a lift on their own because they were too afraid of everything.

I talked with the guys at Greg Smith Equipment about it...and a few construction guys I know and decided I'd be fine.

I've got 4,000 psi concrete somewhere around 5" thick with embedded rebar tied off both directions every 24" with a gravel base under the pour. To me, cutting sections out and pouring deeper didn't make sense because you'd lose or disturb the rebar reinforcement which I felt was as important if not more than the thickness of the concrete or where the expansion joints were.

I also read about the same people suggesting using epoxy to secure the anchors in the concrete which also didn't make sense to me. I used 3/4" anchors that went into holes I drilled 5-6" deep, some went through the bottom of the slab, others did not. After driving the anchors down into the holes and shimming the column bases plumb, I hand torqued each of the anchors down a little bit at a time. You could feel if and when they were biting and clamping the base of the column down onto the slab. I had one pull up and not bite, the anchor itself failed. I ended up driving it down into the gravel base and put a new anchor in it's place that bit and snugged up great.

This is a long explanation but in the end, the slab is stout and established (over 10 years old) and the bases of the columns are clamped down tight to the rebar reinforced slab, expansion joints or not with 3/4" anchors. Basically the anchors make the bases of the columns and the slab become one. The majority of the weight load goes straight down from the posts onto the slab with a little bit of the anchors job to keep the columns from tilting forward or back. With my truck all the way up on the lift, if you grab the back bumper and lift up or down on it, you will see the lift arms and the carriages twist and tweak back and forth a bit as the truck moves, but the columns do not budge. The lift itself is going to self destruct long before the slab will break or the anchors pull out of the floor.