I have a couple of questions. I’m getting close to pouring a 3 foot square concrete pad for my 16 “ Lightbridge in a 11.6 x 11.6 observatory. At first, I planned on just bringing the pad level with the floor but after thinking about it for a while I’m contemplating whether or not this is a good idea.

The concrete pad will be 18 inches thick if level with the floor. My thoughts are if somewhere down the road I decide to add a tracking system is there anything I should do now to ensure I won’t run into problems. Also, would a leveling system such as four J bolts placed into the cement with a plate of some sort for the scope to sit on be a good idea for making up any difference from small ground movement? If I took this approach I would leave the concrete pad below the floor by two inches to compensate for the thickness of the plate.

Lastly, what is a good filler to use between the concrete pad and the floor? I think I remember someone in the past mentioning expansion foam.

Much appreciated,