HomeMy WebLinkAboutIMG_20210816_0002Johnson Engineering Group, Structural Engineering Services
Robert P. Johnson, P.E.
95 Swanson Road, Unit X22
Boxborough, MA 01719
Enfiax44@comcast.net, Cell: 508-517-1831
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On a later date (John provided to me many pictures of the CMU basement
installation') I did not return to the site) the CMU blocks were installed, on all 4 .
sides, around the steel basement posts.
The foundation construction is not a part of this report, I was not present during
any part of the foundation installation, though I was supplied with photographs
showing the installation of the interior spread footings.
The structural construction (including the sheathing and shear wall nailing) meets
the intended criteria of the contract documents and the Massachusetts Residential
Building Code, gth Edition, and is considered complete.
Please see attachment 1, which states the maximum reduction in shear capacity due
to overdriven nails is 25o/o for the Structural I zip system.
Please see attachment 2 which allows an allowable shear capacity (8d nails @2"
spacing) of 937.5 poundsifoot; multiplying this value by a25Yo maximum
reduction results in an allowable shear capaeity of 703 #lfoot.
Our attached calculations on Attachment}, indicate an actual shear load of 465
pounds/foot.
The sheathing and shear wall nailing are structurally adequate in accordance with
the structural requirements of the Massachusetts Building Codo, ge Edition,
Residential.
Per request of the Yarmouth Building Department, we have noted the following:
In some locations, conventional wood framing was upgraded to LW members and
is structurally adequate, due to the following comparisons:
Shear Capacrty (Fv): LVL Fv :285 psi; Conventional Lumber Fv : 85 psi
Flexural Capacity (Fb): LYL Fb : 2,850 psi; Conventional Lumber Fb : 875 psi
Deflection Resistance (E: Modulus of Elasticity):
LVL 2,000,000 psi; Conventional Lumber 1,100,000 psi
The noted values above are multiplied by various factors such as exposure,
duration of load, etc. and vary dependent on the grade of wood.