What is best to frame around basement duct work?
There are a couple of methods to frame around duct work in a basement, depending on your needs. If you will be hanging anything heavy to the above floor joists it would be good to build a frame from angle iron first, then wrap it in 2X material. If you are just framing in for sheet rock, then a basic 2X frame should work.
Framing With Metal
Using a good grade of angle iron, first cut the sizes that you need. There are two ways of assembling the frame, welding and bolting. With welding you may need to prep and do a basic assembly of all of the pieces before taking the parts to the welding shop. If you are welding this yourself, then it is simply a matter of mitering your pieces of angle iron and stitching them together.
Bolting the pieces together may take certain skills as well. You will need to fabricate the necessary brackets to bolt it all together as well as drilling the holes.
Once the frame is assembled you may now raise it into place and bolt it to your floor joists.
Now attach your 2X4 or whatever material you were going to hang from your frame.
The metal will disperse the weight of the material you are going to hang from your floor joists, enabling such things as lighting and other mechanical equipment. Suspending something such as an air conditioner air handler is now a matter of drilling some holes and hanging another frame by using lengths of 1/2 inch all-thread.
Framing With Wood
This may seem like the simpler method of the two at first. But in order for your drywall sheet rock to look like it belongs there, whatever frame you work with will need to be level and plumb. Even if your duct work protrudes below the floor joists.
Again assemble your frame. I usually use 3 or 4 inch sheet rock screws rather than nailing the 2X4’s together. Adjustments are much easier when using screws.
Once assembled raise your frame to the joist height and make sure your are level and plumb.
If you do not have much room to work, or space is limited anyway, you may possibly use 3/4 inch thick plywood for your frames, and build them up just like you would the 2X materials.
Now you should be able to finish your project, covering up your duct work in your basement ceiling.
You only need to lower the ceiling around the duct work. You don’t need to use 2×4’s since it will not be load bearing. 2×2’s will work just as well, and be less expensive. All they need to do is support the drywall. Build a frame on each side of the duct you are trying to conceal. Attach it to the joists with long wood screws. You won’t need to frame under the duct if it is only 10 inches wide. If the total span is more than 16 inches wide, use something like a 1×2 to cross the span, as close to the bottom of the duct as possible. A 1×2 is only 3/4 of an inch thick. Using 1/2 inch drywall will only lower your ceiling under the ducts by 1 1/2 inches or so. If you have to use anything to span under the duct work , be sure you only use 1 1/4 inch drywall screws. Any longer and you risk piercing the ducts. Any shorter and the drywall won’t hold well.
