Technical Bulletin (TB-IJ-7) Subject: Sloped-End Cut IB I-Joists July 2013 (Updated June 2017) This technical bulletin is intended for use with International Beams Inc. products and offers general guidelines for topics that may not be covered in our literature. Appropriateness of details for a specific project should be evaluated by a qualified designer. This technical bulletin may be periodically updated. Check internationalbeams.com to ensure that you have the most recent version.

The preferred way to marry sloped rafter (or sloped I-Joist) framing to I-joists used as ceiling

joists or attic floor attic floor joists is to use a full-depth OSB rimboard and bear the sloped joists

on top of a 2x wood plate on top of the subfloor. This condition is shown in illustration 1.

There are situations where architectural geometric restrictions of the cornice detailing require

that the attic ceiling / floor joist be cut at a slope to match the sloped rafters. NDS-2005

(National Design Specification for Wood Construction) addresses sloped end cuts on

dimensional lumber. These provisions do not apply to I-Joists. The bearing and shear capacity

can be seriously compromised with this type of sloped-end cut on an I-Joist.

International Beams has tested sloped-end cuts on IB I-joists. As a result of these APA-

witnessed tests, we have established maximum end reactions for unreinforced and reinforced

sloped-end cuts. Table 1 (U.S. ASD) and Table 1a (Canadian LSD) with illustration 2 provide

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(TB-IJ-7) Sloped-end cut IB I-Joists July 2013 (Updated June 2017)

reduced end reaction capacities for a range of unreinforced sloped-end cuts for up to 16” deep

IB I-joists. Shallower slopes without reinforcement have significantly lower capacities. When

the special 2x6 stiffeners indicated in illustration 3 are installed, the allowable end reaction is

increased, as indicated in Table 2 (U.S. ASD) and Table 2a (Canadian LSD). For steeper

sloped cuts, the reinforced end reaction capacity with the 2x6 stiffeners approaches the full

capacity of the IB I-Joist.

These tables can be used by a qualified designer to determine if the end bearing capacity of the

sloped-cut IB I-Joist is adequate. Assemblies where sloped rafters are not supported at the

ridge (with a structural ridge beam, wall, or header) are beyond the scope of these tables and

require special engineering analysis. Contact International Beams engineering department for

conditions where the ridge is not supported.

INTERNATIONAL BEAMS

July 2013 (Updated June 2017)

Table 1Maximum End Reaction (Design Capacity) for Sloped-End Cut

IB I-Joists (all series) Without Reinforcement(a, b, c, d)

U.S. ASDIB

I-JoistDepth

(inches)

Slope of End Cut at IB I-Joist(b)

and Maximum End Reaction for Each Depth (lbf)

4:12 5:12 6:12 7:12 8:12 9:12 10:12 11:12 12:129-1/4 485 560 635 710 785 860 935 1,010 1,0859-1/2 480 555 630 705 780 855 930 1,005 1,08011-1/4 435 510 590 665 740 820 895 975 1,05011-7/8 415 495 575 650 725 805 885 960 1,040

14 360 440 520 600 680 760 840 920 1,00016 310 390 475 555 635 720 800 885 965

(a) Allowable end reaction (pounds) with a minimum bearing length of 3-1/2 inches without webreinforcement.

(b) Minimum heel height: 3-1/2 inches.(c) U.S. ASD (allowable stress design). Applicable only to International Beams Inc. I-Joists.(d) Sloped rafters must be supported at the ridge with structural ridge beam, wall, or header.

Assemblies where sloped rafters are not supported at the ridge are beyond the scope of thistable and require special engineering analysis.

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INTERNATIONAL BEAMS

July 2013 (Updated June 2017)

Table 1aMaximum Factored End Reaction (Design Capacity) for Sloped-End Cut

IB I-Joists (all series) Without Reinforcement (a, b, c, d)

Canadian LSD IB

I-JoistDepth

(inches)

Slope of End Cut at IB I-Joist(b)

and Maximum Factored End Reaction for Each Depth (lbf)

4:12 5:12 6:12 7:12 8:12 9:12 10:12 11:12 12:129-1/4 765 885 1,000 1,120 1,240 1,355 1,475 1,595 1,7159-1/2 760 875 995 1,115 1,230 1,350 1,470 1,585 1,70511-1/4 685 805 930 1,050 1,170 1,295 1,415 1,540 1,65511-7/8 655 780 910 1,025 1,145 1,270 1,395 1,515 1,640

14 570 695 820 945 1,075 1,200 1,325 1,450 1,58016 490 615 750 875 1,000 1,135 1,265 1,395 1,525

(a) Allowable end reaction (pounds) with a minimum bearing length of 3-1/2 inches without webreinforcement.

(b) Minimum heel height: 3-1/2 inches.(c) Canadian LSD (limit states design). Applicable only to International Beams Inc. I-Joists.(d) Sloped rafters must be supported at the ridge with structural ridge beam, wall, or header.

Assemblies where sloped rafters are not supported at the ridge are beyond the scope of thistable and require special engineering analysis.

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INTERNATIONAL BEAMS

July 2013 (Updated June 2017)

Table 2Maximum End Reactions (Design Capacity) for Sloped-End Cut

IB I-Joists (all series) With 2x6 Stiffeners(a, b, c, d)

U.S. ASDIB

I-JoistDepth

(inches)

Slope of End Cut at IB I-Joist(b)

and Maximum End Reaction for Each Depth (lbf)

4:12 5:12 6:12 7:12 8:12 9:12 10:12 11:12 12:129-1/4 760 805 855 900 945 990 1,040 1,085 1,1309-1/2 760 805 860 905 955 1,000 1,055 1,100 1,15011-1/4 745 810 880 950 1,015 1,085 1,155 1,220 1,29011-7/8 740 815 890 965 1,040 1,115 1,190 1,265 1,340

14 720 820 920 1,015 1,115 1,210 1,310 1,410 1,50516 705 825 945 1,065 1,185 1,305 1,425 1,545 1,665

(a) Allowable end reaction (pounds) with a minimum bearing length of 3-1/2 inches without webreinforcement.

(b) Minimum heel height: 3-1/2 inches.(c) U.S. ASD (allowable stress design). Applicable only to International Beams Inc. I-Joists.(d) Sloped rafters must be supported at the ridge with structural ridge beam, wall, or header.

Assemblies where sloped rafters are not supported at the ridge are beyond the scope of thistable and require special engineering analysis.

(page 5 of 8)

INTERNATIONAL BEAMS

July 2013 (Updated June 2017)

Table 2aMaximum Factored End Reaction (Design Capacity) for Sloped-End Cut

IB I-Joists (all series) With 2x6 Stiffeners (a, b, c, d)

Canadian LSD IB

I-JoistDepth

(inches)

Slope of End Cut at IB I-Joist(b)

and Maximum Factored End Reaction for Each Depth (lbf)

4:12 5:12 6:12 7:12 8:12 9:12 10:12 11:12 12:129-1/4 1,200 1,270 1,350 1,420 1,490 1,565 1,640 1,715 1,7859-1/2 1,200 1,270 1,355 1,430 1,505 1,580 1,665 1,735 1,81511-1/4 1,175 1,280 1,390 1,500 1,600 1,715 1,825 1,925 2,03511-7/8 1,170 1,285 1,405 1,525 1,640 1,760 1,880 1,995 2,115

14 1,135 1,295 1,450 1,600 1,760 1,910 2,070 2,225 2,37516 1,115 1,300 1,490 1,680 1,870 2,060 2,250 2,440 2,630

(a) Allowable end reaction (pounds) with a minimum bearing length of 3-1/2 inches without webreinforcement.

(b) Minimum heel height: 3-1/2 inches.(c) Canadian LSD (limit states design). Applicable only to International Beams Inc. I-Joists.(d) Sloped rafters must be supported at the ridge with structural ridge beam, wall, or header.

Assemblies where sloped rafters are not supported at the ridge are beyond the scope of thistable and require special engineering analysis.

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INTERNATIONAL BEAMS

July 2013 (Updated June 2017)

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INTERNATIONAL BEAMS

July 2013 (Updated June 2017)

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INTERNATIONAL BEAMS

July 2013 (Updated June 2017)