Fir down... covering it to create exposed timber look

[Warren Lake]

you could also do a rabbet then round most of what is left. Not as good as a mitre but better than a butt joint.

[andrew whicker]

Also, I enjoy all the "fir down" etymology remarks.

The guy I have framed with just calls the drop downs... fir downs. Or maybe he's spelling it furr in his head, but I don't know any better.

Anyway, for me it just means any drop downs and it made sense to me because you "fir" (softwood tree used for building) an area for drywall due to hvac, etc.

I never really thought about it much until now : )

[Kevin Jenness]

Thanks for the replies...

Step 1) 4/4 lumber w/ locking miter
Step 2) Shim bottom piece as necessary centered, flat and straight
Step 3) Scribe sides to ceiling

?

You could assemble and finish the box beams in the shop then scribe as a unit on site and nail jn place, fit the pieces individually as you describe then return them to the shop or at least down to horses for assembly/finishing, or glue and finish them in place. The first requires careful measurement/templating, the second allows for close fitting and minimal mess on site, the third allows for a close fit with unfavorable wall conditions but has obvious potential for glue/finish mess and the pain of doing that work on staging.

[Brian Holcombe]

I do this differently. I make the sides 3/8”, bottom 3/4”. I do a plain glue up, after which I chamfer the sides down to the glue line. It hides the glue line and makes a neat detail.

I put a set of these over actual beams recently and when I visit I often forget that they are faux beams.