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Re: Increased wind loads due to wall removal.

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Mike:

If I read you correctly, you are only concerned with the chance of a
major wind event hitting after the storefront is removed but before the
new wall has been built.  And in particular, you are afraid of the roof
failing due to uplift.  A couple of thoughts come to mind:
1)  Remove and replace in small enough bites (3 days?) so that you can
track George and the other NOAA pets.
2)  Reinforce the roof structure so that a big wind won't hurt.  I can
assist you with that further, but off-line.  Contact me at the address
below.
3)  Add weight to the roof and re-analyze the design using LRFD and
common sense.  Load and Resistance Factor Design (not Little Rock Fire
Dept, as some suggest).  The load factors are a function of the
uncertainty of the loads.  In your case you can control the Dead and
Live loads very precisely during the short period of a wind event during
construction, so can modify those factors using common sense.  So
consider adding a temporary dead load to hold the roof down, control
that weight carefully, and use a low load factor to make sure you don't
overstress the existing roof structure.  Then see if that takes care of
your uplift.

Phil
phil(--nospam--at)joistdesign.com