Attic Fan Joist In Joist Out

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.

Attic fan joist in joist out.

Joist in vs joist out whole house fan installation. Please note that this requires another attic access since the fan will not fit through the shutter opening with the joist in place. Do not cut any joists. Adding a support between the joists enables you to put the fan where you want it in the ceiling.

These are trimmer joists. Because of this i am planning to attach sister 2x8s to each joist. 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. Box out light fixtures.

I am planning to finish a space in my attic. The 1 000 cfm of air flow requires only 1 33 ft2 of net free vent area. Standard ceiling joists sit on 24 inch centers and the space between them is 22 1 2 inches. 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.

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. The planned room will sit over a load bearing wall however part of the existing. Sorry for not responding sooner. 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.

The span of the joist is approximately 7 8 feet. I m a 1 man crew for the most part. Lift the fan through the opening into the attic. Measure the distance between the full joists on either side of the cut joists.

The existing joists are 2x6 and running about 13 from support to support on either side of center. This method leaves the ceiling joists intact. Posted by ryan mcconnell on 03 may 2012 01 35 pm. Mark the joist from the attic use the test hole you.

Unless properly framed a cut joist can weaken the structural support of the house.