Quote:
Originally Posted by JW84345  Why wood framing and not aluminum? |
Fabrication, in a word. The transverse pieces need to be curved, about 3/4" arch across 20". It's possible to shrink and stretch two complimentary "L" extrusions, then rivet their webs together to form an aluminum beam, but a nice piece of 2X lumber on a bandsaw is so much easier.
In addition, riveting aluminum braces in place would require the flanges to face toward the inside of the opening (bucked rivets, of course), which would result in a recess space all the way around.
Although not elegant, the wood works fine and should be dry if the A/C is installed correctly, so no rot.
Zep