Attic location - Contractor Talk - Professional Construction and Remodeling Forum

JamesNLA · 03-07-2007, 01:44 PM

Gotta question for yaz!

Relocating a new FAU to the attic. Plenty of combustable inlet and all looks good! Was wondering about the insulation. No R-30 to speak of however the entire (single story-residential) attic has blown insulation.

Is there a code set requirement for the FAU's height or distance away from, above the blown?
If so, can't we just install more ply atop the CJ's?

Thx

mdshunk · 03-07-2007, 05:32 PM

Quote:

Originally Posted by JamesNLA

If so, can't we just install more ply atop the CJ's?

I've been paging through the code, and can't seem to find anything.

I can tell you what I normally see:

FHU/AHU suspended from chain, and ductwork hung with strapping.
Platform framed with (2)2x6" set "tall ways" perpendicular on top of the ceiling joists/bottom chord and plywood put on top. This at least gives the capability to add more insulation if desired later.

Not sure what brand you're going with, but I stuck in a Trane gas unit last season in an attic that had a detail on that part in the installer booklet.

Mike.GCOC · 03-07-2007, 09:19 PM

You don't mention whether this FAU will have A/C along with the furnace, but if it does then you'll need (at least in Calif.) to install a secondary drain pan under the coil. If not then just check the clearances to combustible surfaces in the specs. Most units require some clearance away from wood surfaces. I've seen some installs where they place sheet metal on the blocking where it sets to handle this.