why not use a wallpoaper stripper for the steam , place timber just off the floor with a slight rise at one end and cover with plastic sheet ,insert the steam pipe at the low end allowing steam to rise slowly.You will need to semi wrap timber in the plastic to keep heat in ,remember these...
Dont know if this will help , I recently made a bench across the end oy my shop which was about 14 feet nothing fancy brick ends with support in middle and 6 x 2 ( 2 x 6 ) across top . then covered half in galvanised metal sheet (it wont be welded on) with a 2 x 2 thin angle across front bolted...