An attic in which a fau is installed shall be accessible by an opening and passageway 30 x 30 in size.
Attic fau framing detail.
Attic access may be reduced to 22 x 30 provided the largest piece of equipment can be removed through the opening.
Fau unit shall be doubled with a minimum 2x6 joists.
30 inches high 762 mm 22 inches wide 559 mm 20 feet max length 6096 mm measured along the center line between the attic access opening and the attic furnace.
Additionally if the attic and roof is conventionally framed ceiling joist under the location of the fau unit shall be doubled with a minimum 2x6 joists.
Install passageway platform minimum 24 inches width and maximum 20 feet in length to fau.
If the attic and roof framing is a pre fabricated engineered truss system an engineering report wet stamped and signed by a licensed engineer shall be submitted for review and approval prior to issuance of a building permit.
If the attic and roof framing is a prefabricated engineered truss system an engineering report wet stamped and signed by a licensed engineer shall be submitted for review and approval prior to issuance of a building permit.
If the attic and roof framing is a pre fabricated engineered truss system an engineering report wet stamped and signed by a licensed engineer shall be submitted for review and approval prior to issuance of a building permit.
Cmc chapter 9 attic furnace diagram.
If the attic and roof framing is a prefabricated engineered truss system an engineering report wet stamped and signed by a licensed engineer shall be submitted for review and approval prior to issuance of a building permit.