Furring strips for OSB ceiling?

[estesbubba]

My pole barn trusses are 10' OC and the builder ran 2x6 joists perpendicular to them 5' OC. As you can see in the pic below each grid is 5x10'. I'm using 7/16" OSB, blowing in at least R-38 insulation, and not putting anything in the attic. I'll hang lights and a few other things but not a lot of load on the ceiling.

Can I ran 2x4x10 furring strips on the bottom of the grid (left to right in pic)? I would run 24" apart which would give 2x5 spacing between support. This seems a lot easier then running 2x4 joists every 24" in the 5' sections.

Here is my truss system.

Essentially it would be the same as my walls except for 5' span in ceiling vs. 10' span in walls.

 

[JoeFin]

Are you asking "Will it sag over time ?

The only way to know that answer is to know the design load of the existing truss system as it is now and then add the weight of the joist you plan to add plus the weight of the sheathing

 

[pattenp]

If I'm understanding you correctly the 2X6's that are 10' long and on 5' centers will be carrying the furring strips plus the sheathing and insulation load. It just seems too much to be hanging on the 2X6's to me. What part of the country are you located in? The roof system you have does not appear to be built to carry much more load than what's already there. Have you consulted the builder or designer?





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[Iron Hoarder]

I have to agree that spacing is too wide and lightly built. You probably should have put a header board across your poles and put the roof trusses on 24" centers. Better make sure what ever you hang is attached to the trusses and not the strips you put in between.

What size are your poles?

 

[estesbubba]

Trusses were engineered for drywall or OSB ceiling plus insulation. My posts are 6x6's which are actually three laminated 2x6's.

I live in Nebraska.

 

[southernfriedcj]

If that was my barn those 2x6's would be 24" OC with a stiff back above on that span at the minimum.

If I was going to use OSB as a ceiling I would run the joists 16" OC so I didn't have to fur down for deadwood.

Me, I'd go 24" centers and use drywall.

edit: If I was in your position I would add a 2x6 between each existing 2x6, put a 2x8 stiff back above(a 2x4 laid flat with a 2x8 up on edge ran across the top of the ceiling joists at mid span) and then fur for deadwood for the OSB.

 

[Iron Hoarder]

I'd be worried about snow load and laminated beams and moisture don't exactly get along unless they have completely impregnated the timber with the bonding resin. I have to be honest and say I wouldn't use anything other than solid timber for poles that are buried in the ground. How wide is the interior of that building? The fact that the roof trusses are made out of 2X6" and not 2X4" helps but that span just seemes to way too much for so few trusses.

 

[Iron Hoarder]

This website has a calculator in the DIY section you can plug all your numbers into including snow load for your area.

http://www.pole-barn.info/

 

[Alchymist]

No way would I ever put up a roof with trusses on 5' centers. IF the trusses were engineered adequately for the span at 5' centers (IF), the most I would do would be 4' on center. Those trusses look pretty light for that span and 5' centers. JMHO though.

 

[alwaysFlOoReD]

The OP said that the trusses are 10' OC. It also looks to me that the top and bottom chords are at least 2x8, maybe more.
I'd be inclined to use 2x4 or 6's - 24" OC using ties/brackets. But knowing the design constraints would be best.

Richard

 

[Alchymist]

Yep, misread that. Yikes, 10' on center would scare the bejazus out of me. Just saying.

 

[estesbubba]

The sealed truss design for my building shows 20 PSF for snow load and 10 PSF for ceiling. A 4x8 sheet of 7/16 OSB is 50 lbs and 24' of 2x4 is 30 lbs. So for a 4x8 section I will add 80 lbs. which is 2.5 PSF which is well under the 10 PSF is was designed for.

 

[Alchymist]

Looks like you answered your own question.

 

[rieferman]

Don't let anyone scare you about truss spacing - as long as your trusses are used in a manner consistent with their design, you will be in good shape. As you seem well aware, truss design isn't a "guessing game"... they're engineered for certain purposes. All those that will say "I'd only space them X feet apart, that's what I've always seen".... well, they probably had trusses designed for that spacing. But there are many other varieties of trusses. Yours (as you state) are designed for the spacing you have, and also to allow for weight of sheetrock (or similar) and insulation.

As for furring strips.. I would lean towards attaching 2x4's at 24" OC in the parallel to the trusses direction (as you inquired about) because the span between connection points will be shorter (as opposed to skipping from bottom cord to bottom cord) and therefore resist sagging better. It looks to me like your builder installed those connectors between the trusses with joist hangers, so it will be a good sturdy connection point.

 

[SteveCh]

You'll be fine. 2 x 4s will do it. Not an engineer, just someone who's built a bunch of stuff. If you were making an upstairs loft storage area, I'd say hold on. But you aren't, so go for it. If you are at all nervous, then use 2 x 6s. But 2 x 4s are gonna be fine.

 

[buddyboy]

i think the question wasn't whether 2x4's would hold osb, it was more or less how many 2x4's you could slap on that ceiling before it exceeded rated load.

you could always use metal hat channel for your furring, that would be lighter than 2x's not sure of the cost difference or if budget is an issue

 

[NUTTSGT]

The sealed truss design for my building shows 20 PSF for snow load and 10 PSF for ceiling. A 4x8 sheet of 7/16 OSB is 50 lbs and 24' of 2x4 is 30 lbs. So for a 4x8 section I will add 80 lbs. which is 2.5 PSF which is well under the 10 PSF is was designed for.

Your trusses are engineered for the load. I'd have no issues doing what you're suggesting in the original post.