I need to install new siding on a 8'x32' portion of my house. (Old aluminum
siding and 1"x6" ship lap lumber has already been removed). I am tempted to
place Hardie Plank directly on the studs (after insulation and house wrap)
and skip any ousided sheathing. The inside of the house is already sheathed
with the same 1"x6" ship lap under the drywall (this is 'lumber' country and
the previous owner was in the logging business) so I don't need the outside
sheathing for shear strength.
BTW, it is nice to be able to hang pictures anywhere you want. All of the
insides are 'lumber under sheetrock'.
All comments and cautions appreciated.

Ivan Vegvary

On 2007-08-14, Ivan Vegvary wrote:

The inside of the house is already sheathed with the same 1"x6" ship
lap under the drywall . . . so I don't need the outside sheathing
for shear strength.

Is the 1x6 sheathing run diagonally? If not, it doesn't provide much
shear resistance. [If you think about shearing a rectangle into a
quadrilateral, aligned points on opposite sides stay the same distance
apart. Then the only shear resistance each board provides is due to
multiple fasteners across its width, and a 1x6 isn't very wide.]

So if the inner board sheathing is not run diagonally, then you should
at least use plywood sheathing on the exterior at the corners. If
your house may be subject to earthquake or high winds, use plywood
sheathing on the entire exterior. There is of course a lot more to
the details, but that's the upshot.

If the inner board sheathing is run diagonally, then you need to
estimate its shear capacity (I don't really know) and compare that
against the potential shear demand (likely strength of earthquakes and
wind).

Cheers, Wayne

Won't the house wrap tend to rip if it is not in front of sheathing?


"Ivan Vegvary" wrote in message
news:lImwi.10$If.6@trndny03...
I need to install new siding on a 8'x32' portion of my house. (Old
aluminum siding and 1"x6" ship lap lumber has already been removed). I am
tempted to place Hardie Plank directly on the studs (after insulation and
house wrap) and skip any ousided sheathing. The inside of the house is
already sheathed with the same 1"x6" ship lap under the drywall (this is
'lumber' country and the previous owner was in the logging business) so I
don't need the outside sheathing for shear strength.
BTW, it is nice to be able to hang pictures anywhere you want. All of the
insides are 'lumber under sheetrock'.
All comments and cautions appreciated.

Ivan Vegvary