raising floor. How do I extend duct work

[joem]

I am raising a floor that has ducts coming up thru the old floor. The new floor will be 14" higher. Can I use wood to build shafts that extend the 14" or does it have to be sheet metal ?
Thanks

[Wgoodrich]

YOu will find a defusser coming through the floor as exisitng. Remove the nails in the floor holding that defusser. Then buy a straight round duct. Cut the duct to length to match the rise in the floor. Slide the new duct onto the existing round duct elbowed up from below the floor. Then screw the joint to secure the joint. Then reinstall you existing defusser at the new floor level mounting it to the new floor.

Hope this helps

Wg

[joem1]

Is there anything wrong in using wood instead of sheet metal ?
Thanks

[Wgoodrich]

Yes, heat ducts are to be made of noncombustible material. Use the proper piping. Not hard and correct. Tin snips and some self drilling screws and about 10 minutes per heat duct.

Good Luck

Wg