Wall Sheathing - do I need blocking?

[BooUrns!]

7/16 is the standard here, as well as across most of the US

As for nails vs staples, many people here use staples, and they have proven to have a better holding abilitiy, and resist pull-thru much better.

But I fail to see how a staple gun is any faster at installing a sheet of OSB than a nail gun

You can bounce fire a bostitch stapler in a 4' row along the osb over the stud/truss in less than 2 seconds. If you're careless and lose track of your line you just hit it again on the right location.

Nails guns need to be lined up and they just can't be fired as fast as a stapler. Air nailers also take longer to load and the cost of the nail fasteners is much much higher than the staples.

In my locale, we don't have the high wind seasonal storm or seismic issues you have in parts of the US so we can use staples for all structural sheathing applications (unless otherwise specified).

When you're doing production framing for a large builder, the lumber packages are supplied by the builder. You build it to meet code and to their order.

I'm not all that proud of the vinyl ghettos that I helped to create. When I look at the ridiculous rates that siders charge for their labour, I can see why new home builders really don't have a choice but to offer anything but vinyl and stucco. Hardie plank doesn't cost much more for materials but they increase the labour rate to offset the increased material cost.

At least they finally pushed through an amendment to the building code here to put firestop drywall under the vinyl siding. There were a few fires in new sub-divisions that stared in one home and spread quickly to dozens because the siding caught fire so quickly and spread.

 

[IDASHO]

Interesting note about the staples.

I have a sheathing stapler, but have never used it. Ill have to pick up a case of staples and give it a whirl. I didnt know they were so fast.

Installing a ton of hardwood T1-11 in the past, I always have a few cases of 8D Galvanized Ringshank siding gun nails. They work fantastic on OSB. Just have to be particular about depth, shooting them with a framing nailer.

The vinyl here is quite disgusting in my opinion. I hate it. At least it is normally reserved for apartment complexes and rentals. And every vinyl order we get is a pretty sweet sale. For one 12-16 unit complex, thats $18-$20k in vinyl.

Run of the mill homes get the hardiplank.

 

[tcianci]

Wow, talk about getting your ******* in a knot! Everyone who has commented has brought valid points to the discussion. I would like to add my 2 cents worth... As far as the shear strength of the WALL assembly, there is probably no difference in strength afforded by the orientation of the panel. The strength axis refers to the panels' ability to resist deflection. In the case of a wall assembly, a wall sheathed with the panel running vertically would be less able to resist deflecting caused by a wayward stud and that would result in a little bulge or dip in the wall surface.

The comment about OSB being essentially non directional is not true.. The "O" stands for ORIENTED. The pieces of wood are arranged with a definite orientation that gives strength along the long dimension of the panel, the same as plywood. In our locale, we always run the panels horizontally, no blocking along the horizontal seam, the unsupported edges of the panel are the ones that lie in the strength axis. Sometmes we use PLY CLIPS to keep the panel edges from deflecting on roof sheathing.

As for the thickness of the panel 1/2 inch plywood or 7/16 OSB is the norm here. The panel thickness contributes to the overall thickness of the wall assembly so, you need to use either 1/2 or 7/16 to be compatible with the jamb depths (typically 4-9/16 inches for 2x4 walls) of the doors and windows. 5/8 plywood laid with the grain 90 degrees to the rafters or trusses makes for a very stiff roof assembly. I have seen 7/16 OSB used on roofs and within a few years you can actually see dips in the sheathing so pronounced that you can see the individual rafters through the roof job! That 1/8 or so between the hallf inch plywood or the 7/16 OSB and the 5/8 plywood on a roof makes a world of difference especially if you are hand nailing the roof shingles. On the thinner stuff, it's like trying to nail into a piece of rubber, everything bounces!

 

[IDASHO]

A little late to the party tcianci, the keg is dry, chips and dip already eaten, and everyone has gone home

 

[porschedude996TT]

How much shear wall is required. I only needed 4 feet from each corner, but I placed OSB on the entire outside wall. I did this because I didn't want to deal with different surface levels or shiming the outside material. Technically I only needed a 4 x whatever the wall height is, in my case 10 foot. If you plan to use the 4 x 8 on a 9 foot tall wall, then you're going to have a seam the whole length. I would stagger the joint and block behind it. How much material and how long is it really going to take, a couple of hours to nail in some 2 x 4 x 14-1/4 pieces... It will improve the wall strength.

 

[skeletonizer]

...there is probably no difference in strength afforded by the orientation of the panel.

The pieces of wood are arranged with a definite orientation that gives strength along the long dimension of the panel, the same as plywood.

.......................

 

[suobs]

OSb can be installed both vertical and horizontal. The shear value is the same.

Nope on the shear value for horizontal unless blocking is used. Vertical is much stronger than unblocked horizontal. About the same with blocking See the link below which is the source of the quote below and also note it pretty much considers plywood and OSB to be equivalent:

http://mgacon0.tripod.com/plywood.htm

Structural Sheathing
Figure 2 shows the two most common ways to sheathe walls with plywood or OSB (Oriented Strand Board)*. Often, the carpenters run the plywood horizontally. For residential construction, builders often use 7/16-inch plywood nailed with 6d common nails. If the plywood is nailed according to minimum code requirements, a 20-foot wall with horizontally applied plywood has a total design shear capacity of 2,460 pounds. That means the wall can resist over a ton of force applied laterally at the top plate.

When the same plywood is installed vertically, the shear capacity goes up to 3,280 pounds. The strength of the vertically sheathed wall is greater because all the plywood panel edges are fastened to solid framing, and there are no plywood joints parallel to the shear force. The weak spot in the horizontally sheathed wall is the continuous plywood joint at 4-foot height where the panel edges are least supported. (When plywood shear walls fail under load, the failure begins at the panel edges, with the plywood pulling away from the framing and pulling out the nails, or tearing through the nail heads.) If you add horizontal 2-by blocking and nail the plywood at the horizontal plywood joints, the wall with horizontal panels would have the same shear strength as the wall with panels installed vertically.

*OSB looks like a bunch of wood chips glued together (that's what it is). OSB performs as well as plywood in most applications — if you keep it dry.

 

[suobs]

I would be curious to know if shear value goes down when sheets are smaller, for example is shear of a wall made of 4x4 sheets with blocking at all intersections the same as shear of a wall made of 4x8 sheets?

 

[grumpygator]

****I don't use osb.I don't care if they call it 7/16,15/32 or 31/64 it's all junk. Omni-directional my a$$. It's cr@p no matter what way you install it.
One hit from my 28 oz estwing = hole the size of the head.
4 Ply 1/2" plyWOOD or get some one else.
Had a talk with the head building inspector a few years back and asked him if osb is really strong both ways why do I have to turn it up on end when i sheet a hip? Since I have known him for over 25 years and we used to work for the same guy bending nails he just looked at me called me a trouble maker and walked away.
So to recap osb bad ,4 ply 1/2 plwood good.
As far as blocking I wold rather put it in the wall then in the trash.
******Just Saying*************Gator************

 

[DigitalFusion]

this thread is over 3 years old.

 

[5lima30]

Our building dept requires blocking only on the corners but I blocked my garage all the way around. BTW, I have seen a lot of 9' sidewalls around here where they used 4x8 sheets and then used a "band board" of 1x or 2x material to make up the difference.