Attic Fan Joist In Joist Out

Joist in vs joist out whole house fan installation.

Attic fan joist in joist out.

Because of this i am planning to attach sister 2x8s to each joist. These are trimmer joists. Standard ceiling joists sit on 24 inch centers and the space between them is 22 1 2 inches. I m a 1 man crew for the most part.

The existing joists are 2x6 and running about 13 from support to support on either side of center. Lift the fan through the opening into the attic. Posted by ryan mcconnell on 03 may 2012 01 35 pm. Unless properly framed a cut joist can weaken the structural support of the house.

Do not cut any joists. 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. Sorry for not responding sooner. Mark the joist from the attic use the test hole you.

If your attic joists won t bear the weight necessary to finish out a living space but the engineer cleared them to support floor decking for light storage you can install inch plywood or. Box out light fixtures. The planned room will sit over a load bearing wall however part of the existing. 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.

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. This method leaves the ceiling joists intact. Please note that this requires another attic access since the fan will not fit through the shutter opening with the joist in place. Putting a support in when you have access to the attic above the ceiling is different than putting.

Adding a support between the joists enables you to put the fan where you want it in the ceiling. 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. 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 span of the joist is approximately 7 8 feet.

The 1 000 cfm of air flow requires only 1 33 ft2 of net free vent area.