Cutting Floor Joists For Ductwork

Proper way to cut a joist and go to images.

Cutting floor joists for ductwork.

If the cut outs are too large or in the wrong location the joist can be weakened and unable to support the load it was designed for. Just be sure to get the sizing sorted out correctly ie a 12x12 duct cannot be replaced by a 3x48 duct same area as there s a lot more friction in the 3x48 but the correction factors for duct shape are surely. Cut a piece of foil tape to length. So in direct correlation to those cut joists are ou.

You may be able to work with a wide shallow duct so you can have a broad not too deep soffit for the cross joist duct run. Use sheet metal duct elbows to work around bends and tin snips to cut the ductwork for a precise fit. The hvac should have gone up a wall not laterally under a floor by cutting joists. If you need to cut through a joist firm up the floor as shown in fig.

Slide the backing up and over the pipe. Peel off part of the backing. Sometimes the best route for a flexible duct run is up and over an obstruction. To prevent problems use saddles or straps to support at regular intervals 4c 4d follow the manufacturer s instructions but in case they get lost here is a list of best practices for.

Sometimes joists are notched at the end where they bear on a wall or sill. Position bathroom vent fans so the ducts can run parallel to the joists right up to where they exit the house. Hvac can run parallel to floor joists though and there are code acceptable ways to cut holes into joists but generally those holes are not big enough for hvac ducts only plumbing and electrical. If the ducts are going to be concealed all seams need to be taped or caulked.

In the 70 s when the new furnace was installed they cut through the floor joists to run the air ducts. Leave backing on the tape on metal ductwork. Attach ductwork that branches off and approaches each vent or register in the house. Tradespeople often need to cut notches or holes in floor and ceiling joists to run pipes ductwork or wires.

To minimize problems with ductwork.