I'm finishing up the mechanical room portion of my radiant heat system. The heat source is water-to-water geoexchange, so an 80-gallon buffer tank is necessary as the heat source is not modulating.

Due to space constraints, I need to place the buffer tank about one foot from the floor drain, which means that the basement slab is sloped in that location toward the drain. The slope is significant enough that the tank rocks and is not level (think the leaning tower of Pisa).

The buffer tank bottom is flat -- there are no feet, adjustable or otherwise.

Two ideas that I had were to either stack up plastic shims to an adequate height and directly shim the bottom of the water heater, or to build a square platform (only 4 inches high -- 2x4's on their side and 3/4" OSB) and shim the platform frame rather than directly shim the buffer tank bottom.

Once the tank is filled with water, it will weigh 800 pounds... It needs to be stable! I suspect that this is a somewhat common problem with tanks in small mechanical spaces... What is typically done?

Thanks,

Jeff

I always build a platform cut to the floor slope. I use shorts of treated 2X4, screw 1-1/8" subfloor to the tops, set it in place, level it up and then scribe each support to match the floor. Don't glue the supports at first because it is easier to unscrew them to cut the scribes with a jigsaw. You can use adhesive for the final assembly. I top it with scraps of some water-resistant inexpensive floor covering in case water drips on it.

I'd pour a few more inches of concrete to create a level area.

Thanks for the ideas... I think I'll give the platform a try first.

Jeff