Attic Fan Joist In Joist Out

Before cutting a joist in a finished ceiling we suggest cutting and removing the sheet rock from the shutter opening figure 7 and then framing the opening between joists and at the side with joist sized lumber extending to and nailed to the adjacent joists as shown in figure 8.

Attic fan joist in joist out.

The span of the joist is approximately 7 8 feet. Lift the fan through the opening into the attic. The existing joists are 2x6 and running about 13 from support to support on either side of center. Joists illustration b the 2 x 4s must be at least as long as the fan 24 or 30 inches and must be spaced at least 36 inches apart so that the fan fits between them.

Standard ceiling joists sit on 24 inch centers and the space between them is 22 1 2 inches. Please note that this requires another attic access since the fan will not fit through the shutter opening with the joist in place. These are trimmer joists. Unless properly framed a cut joist can weaken the structural support of the house.

Look for water stains on the roof sheathing or damp or moldy spots on attic joists and existing insulation as a clue to where leaks might be. The planned room will sit over a load bearing wall however part of the existing. Do not cut any joists. Because of this i am planning to attach sister 2x8s to each joist.

Sorry for not responding sooner. Posted by ryan mcconnell on 03 may 2012 01 35 pm. The 1 000 cfm of air flow requires only 1 33 ft2 of net free vent area. After examining the joists in my attic i don t think i will be able to properly carry a new joist into the attic push it toward the soffits and nail screw it in properly.

Joist in vs joist out whole house fan installation. Measure the distance between the full joists on either side of the cut joists. The fans fit in a rough opening 14 5 inches x 22 5 inches so the unit can be installed in between attic floor joists either 16 or 24 inches on center. I am planning to finish a space in my attic.

Mark the joist from the attic use the test hole you. Adding a support between the joists enables you to put the fan where you want it in the ceiling. Unless you re using mineral wool insulation or your fixtures are rated safe for contact with any type of insulation don t allow the material to touch or cover recessed cans or. This method leaves the ceiling joists intact.

Box out light fixtures.