was wondering if strap ties are supposed connect to top plate and extend below the header to the jack stud for connection or if connecting to the jack stud above the header and below the header is sufficient. The IRC diagram is vague in this description.. Thanks in advance for your feedback
strap ties for portal framing
marcdtom
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was wondering if strap ties are supposed connect to top plate and extend below the header to the jack stud for connection or if connecting to the jack stud above the header and below the header is sufficient. The IRC diagram is vague in this description.. Thanks in advance for your feedback
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The Idea of a "Portal" brace is that It acts as if there is NO hole in the diaphragm that the opening is in....
A circle opening could have one flanged rim a portal brace....like on a military ship hatch
a four sided door needs 4 "moment" connections(bolts and or welds)at each corner connecting the portal braces pieces together to pass the diaphragm loads around the void the opening created.
the strapping will need something that won't bend to transfer the load paths that compress the straps... or stop acting as a partially free connection, pinned instead of fixed.
A few hours reading some Simpson catalogs might offer some clearer examples.
A wind brace should start at the footing (tapcon or anchor bolt in the Crete) and extend to the top truss plate, un interrupted by openings....
twice as many flat braces are needed as sawn in ones...
9 and 10' long wall sheathing can add a lot of strength to a Balloon framed home if it continuous over the rim joist, "splicing the floors together with staggered sheathing installation. Some multi story wood buildings need special treatment at the floor systems to prevent kinky Aiding.
And always consider framing the garage door wall with 2 x 8 studs to add strength at a tiny cost in materials, especially with a 17-19' door lintel that carries the roof truss loads...
A circle opening could have one flanged rim a portal brace....like on a military ship hatch
a four sided door needs 4 "moment" connections(bolts and or welds)at each corner connecting the portal braces pieces together to pass the diaphragm loads around the void the opening created.
the strapping will need something that won't bend to transfer the load paths that compress the straps... or stop acting as a partially free connection, pinned instead of fixed.
A few hours reading some Simpson catalogs might offer some clearer examples.
A wind brace should start at the footing (tapcon or anchor bolt in the Crete) and extend to the top truss plate, un interrupted by openings....
twice as many flat braces are needed as sawn in ones...
9 and 10' long wall sheathing can add a lot of strength to a Balloon framed home if it continuous over the rim joist, "splicing the floors together with staggered sheathing installation. Some multi story wood buildings need special treatment at the floor systems to prevent kinky Aiding.
And always consider framing the garage door wall with 2 x 8 studs to add strength at a tiny cost in materials, especially with a 17-19' door lintel that carries the roof truss loads...
We use a SP top plate to king and them CS20 from header to trimmer and king and then another SP from bottom of king to bottom plate.
Thanks for your comments. We live in a seismic area a which is low and wind speeds off 115 or less category so obviously bracing or “extra bracing” would vary pending region. I have read the Simpson sites and researched these straps quite a bit but I haven’t found a answer to the length. The Mitek site shows the strap connecting the lower jack stud to the up jack stud in the pony wall. And the diagram you have shared, which I have look at and read many times shows the strap in the example extending to top plate. I have a call into Simpson to verify. Also I have read that sheathing the interior side as you would exterior side is acceptable for alternate wall bracing.
The length of the strap was depend on the span that you're connecting of course.
So on that note I would be looking for language on the minimum bearing or strap/lap required from Simpson.
Obviously you're not going to put one inch of strap on the jack.
So on that note I would be looking for language on the minimum bearing or strap/lap required from Simpson.
Obviously you're not going to put one inch of strap on the jack.
So I looked for my brain and found little information by way of prescriptive guides.
Simpson uses and "end length" (one side of connection) and "clear span" (span of header or rim joist passed through) and "cut length" (overall length)
So the overall length /cut length is 2x the end length + the clear span. Easy enough but does not tell you the minimum "end length".
It seems the load capacity dictated by nails/holes needs to be known to determine how much meat the strap needs to have on the ends.
Simpson uses and "end length" (one side of connection) and "clear span" (span of header or rim joist passed through) and "cut length" (overall length)
So the overall length /cut length is 2x the end length + the clear span. Easy enough but does not tell you the minimum "end length".
It seems the load capacity dictated by nails/holes needs to be known to determine how much meat the strap needs to have on the ends.
Go with Simpsom MSTA30 and you will be fine if I understand your specifications as you have described.
Assuming a 1750 lb. tension for Exposure B and SDC C. Wind speed @ 110 MPH etc blah, blah, blah.
Andy.
Assuming a 1750 lb. tension for Exposure B and SDC C. Wind speed @ 110 MPH etc blah, blah, blah.
Andy.
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