Need a book? Engineering books recommendations...

Return to index: [Subject] [Thread] [Date] [Author]

RE: RE: Oversized holes in sill plates

[Subject Prev][Subject Next][Thread Prev][Thread Next]
I would think it would come close, Ralph. The capacity in shear of the
anchor is governed by the capacity of the wood plate. Therefore, the anchor,
in most cases is designed for somewhere between 600 and 800 lbs. The lateral
applied loads is generally much less. With an 1/8" (approx) steel sideplate
and a number 10 cut thread wood screw placed perpendicular to side grain,
the capacity is near 150 lbs per screw (check the AITC tables). I have not
increased the capacity by the old 1.25 for metal side plates because I think
it is included in the latest edition of the AITC. Therefore, with four
screws in place you would get approximately 600 lbs lateral shear.

As far as Simpson is concerned, they provide a slotted hole in the sill
plate of their Strong-wall product. They use a 3" square plate washer
drilled in each corner for a wood screw. I would think that since this is a
shearwall assembly that the action of the plate washer secured to the plate
with wood screws AND the friction developed between the plate and secured
sill would be sufficient. Possibly the values were determined imperically,
but I believe that you may be able to get more information from Simpson on
this issue.

With that said, you do have a valid point (depending upon the spacing and
capacity of the anchor installed) when considering a the load parallel to
grain - which is the action what we generally design for. I think, though,
it would be less expensive in the long run to use this technique and add a
few epoxy anchors as you see fit rather than spend the labor and efforts to
try and epoxy inject all of the oversized holes.


-----Original Message-----
From: Rhkratzse(--nospam--at) [mailto:Rhkratzse(--nospam--at)]
Sent: Wednesday, October 28, 1998 5:14 PM
To: wish(--nospam--at); seaint(--nospam--at)
Subject: Re: RE: Oversized holes in sill plates

In a message dated 10/28/98 4:33:08 PM, wish(--nospam--at) writes:

>one work-around that is used on the new Simpson Strong-wall and Hardy
>which provide slotted holes for last minute adjustment: Use a 2" Square
>plate washer like the Simpson BP's. You can drill the corners to allow
>for a
>small #6 or #8 wood screw (4 ea.). Screw the plate washers in place after
>the wall is adjusted or set. This should remedy the movement of the plate
>due to the oversized holes.

Does the capacity of 4 #6 or #8 wood screws equal the capacity of a 5/8"
anchor bolt?  Is it adequate to transfer the horizontal load to the anchor
bolt at the top of the wood foundation plate (1.5" above the top of
instead of transferring the load through the full depth of the fdn. plate?
tend toward "no" on both of these questions.

Ralph Hueston Kratz, S.E.
Richmond CA