[Strawbale] Over building to code (Was 3 string bales)

[Shody Ryon]

Hi Chris,
The hold downs I am referring to are heavy duty angle
brakets that bolt onto studs and thtough the bottom
plate to a special threaded rod that is in the
concrete. It used to be that it was regular threaded
rod, but now they make some that are a dull color and
have an "s" at the bottom for a better connection.
When these are used in a sheer wall or brace panel,
they make a very strong conncetion to the foundation.
In commercail or multi level buildings, with breaks in
the sheer walls for floor joists, the hold downs are
sometimes used "up-side-down" at the top of the sheer
walls with threaded rod connecting through the joist
bay and subfloor to a hold down in the bottom of the
sheer wall above. In this system, the the nuts and
washers do not put direct pressure on the wood, the
pressure is from the stud and sheer wall assembly.
The roof connection used to be connected with solid or
contiunous blocking between the rafters with A35s
(flat ticos) on every block connecting it to the top
plate. It seemed to be a weak point to me too. None of
the jobs I worked on called for hurrican tie hold
downs on the rafters themselves, in southern
California.
Shody
--- Chris Green <pojeros at telus.net> wrote:

> Shody Ryon wrote:
> > I have noticed that threaded rods for hold downs
> have
> > in many cases been increased from 1/2" to 5/8". 
> > Shody
> >   
> Somewhere I read that in some cases the hold downs
> also have 3x3 plates 
> in place of washers. Fine Homebuilding, perhaps.
> 
> Two weeks ago, I was tasked with tightening a lot of
> these hold downs in 
> one of the townhouses. The ones for load bearing
> walls are 3/4", with 
> the matching round washers, the others are 5/8s,
> etc..
> I judge the connectors to be 'tight enough' when the
> impact driver sets 
> the washers about 1/32th to1/16th into the sill
> plates.
> Since I live in a fairly low earthquake-risk area,
> and the townhouses 
> are on a windy ridge, I'm assuming the engineer(s)
> specified these sizes 
> to help reduce wind uplift. However, in reality,
> there aren't any other 
> 'earthquake tie-down' straps to connect the roof
> trusses through the 
> studs to the foundation, so I think the practice is
> a bit dubious.
> Or maybe somebody forgot to include the rest of the
> details on the plans?
> 
> Cheers,
> 
> Chris Green.
> 
> 
> 
> 
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