framing soffits - Contractor Talk - Professional Construction and Remodeling Forum

jforrester01 · 01-14-2008, 09:58 PM

In your opinion what is the best method for framing soffits around long runs of ductwork or plumbing. Keeping in mind to keep the framing as tight to the ductwork as possible and straight corners for the drywallers?

Guisbuild · 01-14-2008, 10:30 PM

the quickest way I have found is to keep the rips of plywood from the frame job and use them to box in the duct work,...

I usually attach a 2x with staples to one factory edge and nail it up to joists. Then run 2x perpendicular to that ply to wall 2' on center or 16" if you prefer.

kevjob · 01-14-2008, 10:55 PM

plywood is the best way for straight true long runs

wallmaxx · 01-14-2008, 10:57 PM

I like 2x4 ladders (flat) then plywood to add rigidity.

neolitic · 01-14-2008, 11:02 PM

I attach 2X to joist
and 2X to bottom of ply,
then string the bottom edge
as I hang it.

FRAMERBEN · 01-15-2008, 08:06 PM

That 's An easy one J. Rip the longest 2x4 you have in half. Rip some 1x2 strips out of 3/4 sheating, cutting them to the ammount that you are having to drop the soffit to clear the plumbing +2". Butt the 2x2's end to end to create the length of your soffit. Nail the 3/4 rips to the inside of your 2x2s. what you have just created will look like a ladder with the 3/4 rips 2' o.c. In other words you will have 1 2x2 at the top and one at the bottom. With the 3/4 rips perpindicular to the 2x2s. Now nail it to the bottom of the floor joists. If the plumbing is next to a wall, return the soffit to the wall using 2x4sturned 1 1/2 waays to give optimal head clearance. Call me if this dosen't make sense. Ben

Pavola · 01-15-2008, 08:49 PM

Metal track systems work great. They're installed just like drop ceilings and the profile is only 1 1/2. You get a very flat drywall finish which is important when lowering the ceiling to cover the main ducts, etc. I tie this into a plywood and 2x2 section to return up to the normal ceiling height. The bigger the soffit area is, I've found the track system to be quicker and better, but the cost and prep work isn't very effective for small soffits.

A W Smith · 01-15-2008, 10:49 PM

I make ladders out of 5/4 x 3 spruce bridging. if I am rocking at the same time I just screw the spruce to the drywall without making the rungs to the ladders. I have used scrap plywood as rungs behind the spruce when I was running short of spruce.

Joe Carola · 01-16-2008, 06:20 AM

Sometimes I shoot a nailer into the bottom of the joists and nail a straight 2x10 or 2x12 on edge into the nailer. This way you can get long lengths shoot them in and your done, then just sheetrock over the 2x.

jforrester01 · 01-16-2008, 09:24 PM

Thanks for the info....and framerben you're idea would have worked great in our last basement with 7'4" ceilings at the tall points. Is this the method use always or just when head clearence is really close? Do the 2x2's stay pretty true? Framerben needs to change his name to reflect his expanding knowledge in the trim and remodeling trades.

framergreg · 01-16-2008, 10:00 PM

if ya want ease and a straight run use TGIs or rim board for tgi. we use the rims to cut stair stringers too!!!

wallmaxx · 01-17-2008, 12:22 AM

Quote:

Originally Posted by framergreg

if ya want ease and a straight run use TGIs or rim board for tgi. we use the rims to cut stair stringers too!!!

OSB rimboard or LSL?

I wouldn't think the standard wafer OSB rim would be structural enough...its strength being in compression not in deflection when applied over a clear span under load.

I have used 11 7/8" x 1 3/4" LVL stringers....even true 4 x 12 PT timbers with Zmax angle brackets lagged in to hold concrete treads but not standard rim. Something new on this site every day.

Mike

FRAMERBEN · 01-17-2008, 05:39 AM

MAN, TJI's or rim board. That stuff is way to expensive to frame a soffit in a basement. J the 2x2 ladder will stay as true as your floor joists up and down, so they sometimes they need tweaking up and down. As far as in and out, that depends on how straight of a line you can make. If the plumbing is in the middle of the room, you would use a ladder on each side with 2x4 celing joists going from ladder to ladder. To permanantly secure, a diagonal brace inside the soffit will hold it true. maybe a couple.....every 4'. Ben