Hi,
I would like to have some opinions regarding the use of T111 sheathing in shear walls. Also, what shear design values would be appropriate for use with T111?
Thanks in advance.
I would check with the manufacturer to see if it has a proper qualification for shear wall panels. Specifically it should have an ICC report or some other certification stating that it meets the Structural I or other qualification.
The advantage to T1-11 is that you get your code structural strength (if code rated) and siding at the same time rather than using OSB or Ply CDX for structural and then siding over it for protection. The disadvantage is T1-11 tends to split and crack from exposure much more than many siding products. Advantages: Installed as part of the framing process; inexpensive; solid, can be stained or painted. Disadvantages: The disadvantage is T1-11 tends to split and crack from exposure much more than siding. Limited styles; fairly high maintenance; some feel that it has a "cheap look".
15 years ago there was litigation against GP fiberboard T1-11 that soured many peoples opinion of T1_11 in the residential market.
IBC has a table 2306.4.1 that is the recommended shear for wood structural panels that includes plywood siding. APA states that T1-11 is a trade name for APA 303 rated siding. The values vary with thickness of siding and nail spacing. But as an example, 15/32 with fastener penetration of 1-1/2" into framing and 10d nails at 6" oc, the value is 310 lbs per foot.
Be aware that A303 siding has a lap at the vertical joints. Normal installation for non-shearwall applications would be a single row of nails through the lap. For a shearwall application, you need to clearly indicate on the drawings that TWO rows of nails are required, one for each panel, with proper edge dstances.
