Installing HardiePanel over Simpson Strong-Tie Strapties
What is the best method for intalling HardiePanel Vertical Siding over studs that already have installed Simpson Strong-Tie Strapties such as HST/MST/MSTC/MSTA, etc., (page 168 of the Simpson Strong-Tie 2011-2012 Wood Construction Connector catalog)?
The strap-ties are used to connect two wall plates and wall studs together separated by floor joists. The idea being that the staps will improve a stud walls’ ability to resist wind and eartquake loading. In my case, I have used them to connect or bridge I-Joists supporting a loft floor.
My wall assembly is like this: Mud sill, bottom plate, wall stud, double top plate, BCI-Joist, plywood floor sheating (loft floor), and then a double top plate again into which the roof trusses are secured. The walls are already covered with 5/8ths structural plywood, then the strap-ties nailed into the wall studs and into the upper-most double top plate.
The issue or problem is securing the HardiPanels through the metal strap-ties. The obvious method is to drill pilot holes though the HardiePanel and through the metal strap-ties through which a nail can be installed into a stud. Of course according to Simpson, drilling additional holes is a no-no. 4d or 6d nails can be used to fasten HardiPanels to wall studs and plates. According to James Hardie, the nailing schedule of the HardiPanels to the structural members must follow local building codes. Following the 2009 IRC, nials would be required 6 inches on the edges and 12 inches in the field. The HardiePanels will have batten boards installed over each joint.
So, what is the best “work-around” for installing HardiePanels to the stud walls?
Replies
That 6/12 is for shearwall construction, not for exterior sheathing (unless you are using it as a shearwall).
The easy answer for this is to fur everything out with 1x and attch the panels to that. This way you can make sure that everything is perfectly flat planed over those bumps in the wall from the metal plates, which can be up to 1/4" thick. You would notch you furring for that.
You would apply building paper before that furring ov course, but in the end you woudl have something called a "Rain Screen" that adds a degree of protection from water infiltration if you do it correctly.
1" wouldn't be enough
1" wouldn't be enough thickness to permit nailing.
Actually this raises something I wondered about:
Is it OK to let into framing members for connector hardware?
In this case, could he route out the areas where the straps will lie so both the strap and the fastener heads lie beneith the surface plane. This would allow the Hardy sheet to act as a shearwall and allow it to lie flat.