HomeMy WebLinkAboutJoist Modification ReportCanyon Engineering, Inc.
January 22,2018
Charlie Apple
491 Elk Springs Drive
Glenwood Springs, CO 81601
RE: Joist Modifications
Dear Charlie
At your request, I conducted a site visit to
your new home on January 18th. The
purposes of the visit was to review the
holes drilled into the floor joists for
electrical and mechanical systems. The
Apple residence is currently under
construction. Framing and the rough-in
electrical has been completed. The
electrician has drilled as many as
fourteen 1Tz" diameter holes in the floor
joist located above the 4' hallway.
The floor system is constructed of 11-
718" BCl60 2.0 joists placed a116" clc.
The joist size was selected to clear span
16' with a live load of 40 psf and dead
load of 15 psf. The BCI design catalog
specifies the size and location of holes
drilled into the joist web. lt is acceptable
to drill a 1- Tz" diameter hole anywhere in
the web provided that there is 3" of
clearance to any adjacent hole. Currently
the holes are closer than allowed by the
BCI design recommendations and would
not be acceptable for the joist with a 16' span
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The holes were drilled into the joists that span only 4'. lf framed with dimensional
lumber, the floor load could be supported with 2x4 members at 16'c/c. The multiple
holes have not reduced the structural strength of the joist lower than that of 2x6 framing
For this reason, it is my opinion that the joists can still support the required loading. No
remedial action is needed.
P.O. Box 398. Glenwood Springs, CO 816oz . (gZo) 94S-S$8 ' FAX (gZo) 945-5$B
Joist Holes
January 22,2018
Page2 of2
The plumber has cut a 6" hole in the
laundry room ceiling joists for a drain
pipe. The hole is 18" from a bearing
wall. The joist span is 8'. BCI design
recommends that a 6" hole be located
a minimum of 29" from a bearing wall.
The requirement relates to high shear
stress in this area. However, the
joists were designed to span 16'.
The shear stress in the web by the
pipe is only Tz of the maximum
allowable shear stress for the joist.
As we discussed, it is recommend that you reinforce the affected joists for additional
safety. Reinforce the joists by gluing and nailing a Sls" plywood patch above the pipe
openings. The patch size is about 4-112" x 5' and it is placed on both sides of the joist
above the pipe.
Thank you for requesting our review of this issue. Please give me a call if you have any
questions.
Sincerely,
CANYON ENGINEERING, INC.
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Charles Peterson, P.E.
Design Engineer
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Canyon Bngineering, Inc.
February 9, 2018
Charlie Apple
491 Elk Springs Drive
Glenwood Springs, CO 81601
RE: Second Joist Modifications
Dear Charlie:
At your request, I made a return trip to your new home on February 9b. The second trip was to inspect a
floór joist modification similar to the modifications that were reviewed on January 18th. At issue is the
size, location and number of holes that have been cut into the web of the joist for utilities.
The recently reviewed modification is a 4" Ø
hole cut in the web of the 1 1-718" BCI 60 2.0
floor joist spanning 6'. The hole was cut for a
waste water pipe. The opening appears to be
within 18" of the bearing edge. This is the
minimum distance identified in the BCI
Standards for hole, location and sizing.
The opening has been reinforced with the same
technique listed in the previous report. The
reinforcement has been inspected and found to
be installed correctly.
The modified joist has been sufiiciently
reinforce to resist the impose loads. No
additional action is needed.
Please give me a call if you or the Building Official have any questions. Thank you
Sincerely,
CANYON ENGINEERING, INC
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Charles Peterson, P.E.
Design Engineer
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P.O. Box 398 . Glenwood Springs, CO 816oz . (97o) 945-5$8 . FAX (gZo) 945-588