How many screws

[krisway]

Looking to put 7/16" OSB for a ceiling on my 2ft rafters. How many screws per 4x8 sheet is required?

Any tips on screwing the edge of the OSB when trying to catch the edge of the 2x4?

 

[woodrail]

I would run a bead of adhesive and screw every 16" inches.

Predrill the screws that are within 3/4" of the edge or else you are likely to blow them out.

Can you get t&g in that material?

 

[Higgins]

IMHO- attach the boards with drywall screws and a screw gun. Insert a drywall screw every 6 to 8 in. along the length of every wood stud that the board covers. Also, insert a screw around the outside edges of the board. Some glue on the 2x would also help!

 

[readhead]

Where are you located? Glue may not be a good idea.

 

[woodrail]

Gotta ask - What location is glue not a good idea?

I'm talking about construction adhesive, not elmers.

 

[readhead]

Earthquake country and some high wind areas. You can make the structure " to solid".

 

[Higgins]

Hummmmm, That wasn't a problem when a friend built his house in Alma, CO. We glued and screwed everything.................. Now that was around 15 yrs ago! Same here in IL, but I'm not in a high wind area!

 

[Slackerzinc]

Don't use drywall screws in osb. They won't take the torque, use deck screws.

 

[Tim The Tool Man]

Don't use drywall screws in osb. They won't take the torque, use deck screws.

x2 on drywall screws! But I would use lathing screws over deck screws. Lath screws have a washer built into the head and won't dig through the OSB. Also pre-drill the edges...

 

[cburnscrx]

x2 on drywall screws! But I would use lathing screws over deck screws. Lath screws have a washer built into the head and won't dig through the OSB. Also pre-drill the edges...

Ding Ding Ding! We have a winner.

 

[DHCrocks]

Earthquake country and some high wind areas. You can make the structure " to solid".

really? i would think that adding adding more stiffeners would help to brace the strucutre more and be a benefit not a liability. They do add plywood to exterior shear walls to make it more stronger so it doesnt rack. it's not like wood is a ridig product it will give some.

 

[Big-Foot]

I use #8 construction / deck screws .... I also use a good grade of construction adhesive. I have done this for years on interior construction and have not had any troubles. You don't have to sink the screw so deep as to destroy the edge of the OSB, but you can get it just below the surface to enable a smooth joint.
I will use a 2" or longer screw and angle them in toward the stud about 1" away from the egde. The adhesive will really make it a lot stronger overall..
I personally cannot understand why you would not want to use screws and glue in construction where the joint is not exposed to the weather.

 

[Tim The Tool Man]

I use #8 construction / deck screws .... I also use a good grade of construction adhesive. I have done this for years on interior construction and have not had any troubles. You don't have to sink the screw so deep as to destroy the edge of the OSB, but you can get it just below the surface to enable a smooth joint.
I will use a 2" or longer screw and angle them in toward the stud about 1" away from the egde. The adhesive will really make it a lot stronger overall..
I personally cannot understand why you would not want to use screws and glue in construction where the joint is not exposed to the weather.

I would only avoid glue if I thought I might need to remove a sheet in the future to run a wire or something. But for structural rigidity and all that I would always recommend glue. I have never heard of being too well built for high wind or earthquake???

 

[kbs2244]

Don’t the sheets come with marked fastening points marked?
Some real good money was paid to some real good guys to come up with those spots.

 

[readhead]

There is a lot of science that goes into this but the simple answer is that if the diaphram is to rigid and not allowed a certain amount of movement certain attachments will come apart,ie plate to stem wall is one example. The glue will not provide enough extra attachment to warrant the effort and will be a pain in the *** if he ever goes to remodel. The best attachment would be ring shank nails. But in this case the lath screws mentioned above would be a good choice. Screws have very little shear strength. That is why shear sheeting is nailed.

 

[Falcon67]

Don't use drywall screws in osb. They won't take the torque, use deck screws.

This. Used 5 per joist on 24" centers on the ceiling, about every 16~18" on vertical walls. That comes to 25 per sheet on the ceiling so you'll go through them quick. No sag problems. Still used almost 10 lbs of 1 5/8" deck screws. I used a drywall screw point to set the screws flush, like it was drywall.

 

[pmilin]

Just curious why OSB on the inside instead of sheetrock.

 

[Big-Foot]

Just curious why OSB on the inside instead of sheetrock.

- Impact resistance
- Stronger construction overall
- Mount cabinets or just about anything anywhere you want without hunting for a stud

 

[dragonballz]

Is OSB more expensive than sheetrock or plywood?

 

[Falcon67]

Is OSB more expensive than sheetrock or plywood?

Was 7.95/sheet when I put it up so it was maybe $1 more. Now it's $13.99/sheet.

Why - no need to finish (I like the warm color), no dents when I bang into it with a car/jack/8' 2x4/etc and I can hang just about anything on any wall.

 

[pmilin]

Ok. I see the reason for OSB on walls but the OP is putting it on the ceiling. Also I would never mount cabinets or anything heavy just on OSB without at least a few screws into studs. Impact resistance yes.

 

[kbs2244]

Even a painted OSB panel is lighter than drywall.
If on a ceiling, all the more reason to use it.

IMHO the only thing drywall has in it's favor is fire resistance.
And there are fire resistant paints that can match it.

It is pretty but I just do not think it has any place in a working space.