Decking Under Attic Furnace

Plywood around furnace air handler on attic retro now be honest hear how many of you guys when you replace the indoor unit dial it in with plywood around the unit not to sit on must be rated and sheetmetal under i suspend mine on trapeeze so the next guy doesnt have to roll in the itchy stuff.

Decking under attic furnace.

Look up at the roof area. Be sure to cut the ripped pieces to the proper length before taking them up into the attic. However since very few attics have an opening that s wide enough to pass a full sheet of plywood through the four by eight sheets should be ripped lengthwise. Locate the rotted roof decking.

The pros and cons of placing a furnace in the attic indicate that this idea is not a good one under most circumstances. Most of the issues that furnace might experience in an attic are due to extremely cold weather in this poorly insulated space. Attic furnace passageway and service area electrical requirement. Mold growing on the sheathing in your attic is a serious problem that shouldn t be ignored.

Does mold on attic sheathing have to be removed. Not only will it interfere with the efficiency ratings of your equipment but it can also cause damage to your unit that may go undiscovered for some time. Note bad areas for removal. Attic furnace installation must comply with you local mechanical code or imc international mechanical code if such was adopted in your area.

The decking material can be half inch plywood. There must be a passageway at least 30 inches high and 22 inches wide and not more than 20 feet in length. Mcyr marcel cyr cmi july 5 2010 6 18pm 9. Decking in front of the hvac equipment must be at least 30x30 inches.

High efficiency furnaces aren t usually recommended for an attic. Gain access to the attic to inspect the plywood or roof decking. I call it out when there is no decking on the passageway. The following are attic furnace installation requirements based on 2009 irc and 2009 imc the codes refer to it as appliances in attics.

Attic furnace access passageway and platform. A furnace can suffer from a drop in energy efficiency if it s in an unconditioned space such as an attic.