Installation Instructions

P. 13
P3 Joist Typical Holes
FIGURE 6
Web Hole Rules and Specifications
One of the benefits of using P3 Joists in residential floor construction
is that holes may be cut in the joist webs to accommodate electrical
wiring, plumbing lines, and other mechanical systems, thereby mini
-
mizing the depth of the floorsystem.
Rules for Cutting Holes in P3 Joists
1. The distance between the inside edge of the support and the center
line of any hole shall be in compliance with the requirements of Table 4.
2. P3 Joist top and bottom flanges must NEVER be cut, notched, or
otherwise modified.
3. Whenever possible field-cut holes should be centered on the middle
of the web.
4. The maximum size hole that can be cut into a P3 Joist web shall equal
the clear distance between the flanges of the P3 Joist minus1/4”.
Aminimum of 1/8” should always be maintained between the top or
bottom ofthe hole and the adjacent P3 Joist flange.
5. The sides of square holes or longest sides of rectangular holes should
not exceed three-fourths of the diameter of the maximum round
hole permitted at that location.
6. Where more than one hole is necessary, the distance between adja
-
cent hole edges shall exceed twice the diameter of the largest round
hole or twice the size of the largest square hole (or twice the length of
the longest side of the longest rectangular hole) and each hole must
be sized and located in compliance with the requirements of Table 4.
7. Holes measuring 1-1/2” shall be permitted anywhere in a cantile
-
vered section of a P3 Joist. Holes of greater size may be permitted
subject to verification.
8. A 1-1/2” hole can be placed anywhere in the web provided that it
meets the requirements of rule 6 above.
9. All holes shall be cut in a workman-like manner in accordance with
the restrictions listed above and as illustrated in Figure 6.
10. Limit of 3 maximum size holes per span.
11. A group of round holes at approximately the same location shall
be permitted if they meet the requirements for asingle round hole
circumscribed around them.
Cutting the Holes
• Never drill, cut, or notch the flange. Never over-cut the web.
• Holes in webs should be cut with a sharp saw.
• For rectangular holes avoid over cutting the corners as this can cause unnecessary stress concentrations. Slightly rounding the corners
is recommended. Starting the rectangular hole by drilling a 1” diameter hole in each of the 4 corners and then making the cuts between
the holes is another good method to minimize damage to I-Joist.
FIGURE 6
Do Not Cut or Drill
See rule 11.Minimum distance from face of support
to the center of hole (See Table 4)
3/4x
diameter
2x diameter
of larger hole
Do not cut or notch flanges.
(An exception is birdsmouth cuts in
roof details 7h & 7j in User Guide.)
Do not violate
hole chart rules.
Do not birdsmouth
cut bottom flange at
high end of rafter.
Wood I Beam Support Beam Rafter
Do not hang
P3 Joist by top
flange or web.
Do not bevel cut
joist beyond inside
face of wall.