Getting ready to pour my 3/4" pex heated concrete floor in a 30' x 50' x 16 ' all steel prefab shed , no windows but have two 10' x 10' OHDs , a 8' x8' OHD and a 4' x 7' man door with a poured 10" x 4' foundation . Work shop area will be 35' x 30' area with a 9,000 lb Rotary 2 post hoist; a OLD...