Compression posts play an integral role in designing a Strong-Rod Anchor Tiedown System for shearwall overturning restraint. As tension loads are resisted by the Strong-Rod ATS steel rods, adequate compression elements are crucial in the opposite end of the shearwall. Compression posts are either single members or multiple members. A Designer may use either a symmetrical or an asymmetrical post configuration. These elements are specified by the Designer. Simpson Strong-Tie offers guidance by providing standard tables for compression elements.
An equal number of posts or studs on each side of the Strong-Rod. End of the shearwall requires extra framing to maintain edge-of-wall line.
Moment Arm = Center of Rod to Center of Rod
Nailing Example: (4) total compression members: 2" o.c. edge nailing x 4 = 8" o.c. nailing at each compression member.
Solid Lumber Sizes | |||||||
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Framing | Lumber Size (each side of Rod) |
Allow. Perp. To Grain, Pc (lbs.) |
Allowable Parallel to Grain, Pc (lbs.) | ||||
Plate Height (ft) | |||||||
8 | 9 | 10 | 11 | 12 | |||
(160) | (160) | (160) | (160) | (160) | |||
4-inch Wall | 1-2x4 | 6,565 | 6,685 | 5,330 | 4,335 | 3,590 | 3,020 |
1-3x4 | 10,940 | 11,145 | 8,880 | 7,225 | 5,985 | 5,035 | |
1-4x4 | 15,315 | 16,730 | 13,320 | 10,830 | 8,970 | 7,545 | |
2-3x4 | 21,875 | 22,290 | 17,760 | 14,450 | 11,975 | 10,075 | |
1-4x6 | 24,065 | 26,195 | 20,880 | 16,990 | 14,075 | 11,840 | |
1-4x8 | 31,720 | 34,400 | 27,445 | 22,350 | 18,525 | 15,590 | |
1-4x10 | 40,470 | 43,700 | 34,905 | 28,445 | 23,590 | 19,860 | |
2-4x6 | 48,125 | 52,395 | 41,755 | 33,980 | 28,150 | 23,685 | |
1-4x12 | 49,220 | 53,145 | 42,455 | 34,595 | 28,690 | 24,155 | |
2-4x8 | 63,440 | 68,795 | 54,890 | 44,695 | 37,045 | 31,180 | |
6-inch Wall | 1-2x6 | 10,315 | 22,060 | 18,455 | 15,475 | 13,075 | 11,145 |
1-3x6 | 17,190 | 36,765 | 30,760 | 25,795 | 21,790 | 18,580 | |
1-4x6 | 24,065 | 55,685 | 46,420 | 38,835 | 32,760 | 27,900 | |
1-6x6 | 37,815 | 71,865 | 62,220 | 53,405 | 45,820 | 39,470 | |
1-6x8 | 51,565 | 95,800 | 83,445 | 71,945 | 61,915 | 53,455 | |
1-6x10 | 65,315 | 118,340 | 103,750 | 89,895 | 77,635 | 67,185 | |
1-6x12 | 79,065 | 143,255 | 125,590 | 108,820 | 93,980 | 81,330 | |
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Multiple 2x Sizes | |||||||
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Framing | Lumber Size (each side of Rod) |
Allow. Perp. To Grain, Pc (lbs.) |
Allowable Parallel to Grain, Pc (lbs.) | ||||
Plate Height (ft) | |||||||
8 | 9 | 10 | 11 | 12 | |||
(160) | (160) | (160) | (160) | (160) | |||
4-inch Wall | 1-2x4 | 6,565 | 6,685 | 5,330 | 4,335 | 3,590 | 3,020 |
2-2x4 | 13,125 | 13,375 | 10,655 | 8,670 | 7,185 | 6,045 | |
3-2x4 | 19,690 | 20,060 | 15,985 | 13,005 | 10,775 | 9,065 | |
4-2x4 | 26,250 | 26,745 | 21,315 | 17,345 | 14,365 | 12,085 | |
5-2x4 | 32,815 | 33,435 | 26,645 | 21,680 | 17,960 | 15,110 | |
6-2x4 | 39,375 | 40,120 | 31,970 | 26,015 | 21,550 | 18,130 | |
7-2x4 | 45,940 | 46,805 | 37,300 | 30,350 | 25,145 | 21,155 | |
8-2x4 | 52,500 | 53,495 | 42,630 | 34,685 | 28,735 | 24,175 | |
9-2x4 | 59,065 | 60,180 | 47,955 | 39,020 | 32,325 | 27,195 | |
6-inch Wall | 1-2x6 | 10,315 | 22,060 | 18,455 | 15,475 | 13,075 | 11,145 |
2-2x6 | 20,625 | 44,120 | 36,910 | 30,955 | 26,150 | 22,295 | |
3-2x6 | 30,940 | 66,180 | 55,365 | 46,430 | 39,225 | 33,440 | |
4-2x6 | 41,250 | 88,240 | 73,825 | 61,905 | 52,300 | 44,590 | |
5-2x6 | 51,565 | 110,300 | 92,280 | 77,385 | 65,375 | 55,735 | |
6-2x6 | 61,875 | 132,360 | 110,735 | 92,860 | 78,450 | 66,885 | |
7-2x6 | 72,190 | 154,420 | 129,190 | 108,335 | 91,525 | 78,030 | |
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Solid Lumber Sizes | |||||||
---|---|---|---|---|---|---|---|
Framing | Lumber Size (each side of Rod) |
Allow. Perp. To Grain, Pc (lbs.) |
Allowable Parallel to Grain, Pc (lbs.) | ||||
Plate Height (ft) | |||||||
8 | 9 | 10 | 11 | 12 | |||
(160) | (160) | (160) | (160) | (160) | |||
4-inch Wall | 1-2x4 | 4,460 | 5,865 | 4,675 | 3,805 | 3,155 | 2,655 |
1-3x4 | 7,440 | 9,775 | 7,795 | 6,345 | 5,260 | 4,425 | |
1-4x4 | 10,415 | 13,685 | 10,910 | 8,885 | 7,360 | 6,195 | |
2-3x4 | 14,875 | 19,550 | 15,590 | 12,690 | 10,515 | 8,850 | |
1-4x6 | 16,365 | 21,420 | 17,100 | 13,930 | 11,550 | 9,720 | |
1-4x8 | 21,570 | 28,115 | 22,475 | 18,320 | 15,195 | 12,795 | |
1-4x10 | 27,520 | 35,705 | 28,575 | 23,315 | 19,350 | 16,300 | |
2-4x6 | 32,725 | 42,840 | 34,200 | 27,860 | 23,095 | 19,440 | |
1-4x12 | 33,470 | 43,420 | 34,750 | 28,355 | 23,530 | 19,820 | |
2-4x8 | 43,135 | 56,235 | 44,945 | 36,640 | 30,390 | 25,590 | |
6-inch Wall | 1-2x6 | 7,015 | 19,200 | 16,110 | 13,540 | 11,450 | 9,770 |
1-3x6 | 11,690 | 31,995 | 26,855 | 22,565 | 19,085 | 16,285 | |
1-4x6 | 16,365 | 44,795 | 37,595 | 31,590 | 26,720 | 22,800 | |
1-6x6 | 25,715 | 54,005 | 47,670 | 41,530 | 36,005 | 31,245 | |
1-6x8 | 35,065 | 71,720 | 63,710 | 55,790 | 48,550 | 42,240 | |
1-6x10 | 44,415 | 88,250 | 78,910 | 69,485 | 60,725 | 52,990 | |
1-6x12 | 53,760 | 106,830 | 95,520 | 84,115 | 73,505 | 64,145 | |
|
Multiple 2x Sizes | |||||||
---|---|---|---|---|---|---|---|
Framing | Lumber Size (each side of Rod) |
Allow. Perp. To Grain, Pc (lbs.) |
Allowable Parallel to Grain, Pc (lbs.) | ||||
Plate Height (ft) | |||||||
8 | 9 | 10 | 11 | 12 | |||
(160) | (160) | (160) | (160) | (160) | |||
4-inch Wall | 1-2x4 | 4,460 | 5,865 | 4,675 | 3,805 | 3,155 | 2,655 |
2-2x4 | 8,925 | 11,730 | 9,355 | 7,615 | 6,310 | 5,310 | |
3-2x4 | 13,390 | 17,595 | 14,030 | 11,420 | 9,465 | 7,965 | |
4-2x4 | 17,850 | 23,460 | 18,705 | 15,230 | 12,620 | 10,620 | |
5-2x4 | 22,315 | 29,320 | 23,385 | 19,035 | 15,775 | 13,275 | |
6-2x4 | 26,775 | 35,185 | 28,060 | 22,840 | 18,930 | 15,930 | |
7-2x4 | 31,240 | 41,050 | 32,735 | 26,650 | 22,085 | 18,585 | |
8-2x4 | 35,700 | 46,915 | 37,415 | 30,455 | 25,240 | 21,235 | |
9-2x4 | 40,165 | 52,780 | 42,090 | 34,265 | 28,395 | 23,890 | |
6-inch Wall | 1-2x6 | 7,015 | 19,200 | 16,110 | 13,540 | 11,450 | 9,770 |
2-2x6 | 14,025 | 38,395 | 32,225 | 27,075 | 22,905 | 19,545 | |
3-2x6 | 21,035 | 57,595 | 48,335 | 40,615 | 34,355 | 29,315 | |
4-2x6 | 28,050 | 76,790 | 64,445 | 54,150 | 45,810 | 39,090 | |
5-2x6 | 35,065 | 95,990 | 80,560 | 67,690 | 57,260 | 48,860 | |
6-2x6 | 42,075 | 115,185 | 96,670 | 81,230 | 68,710 | 58,635 | |
7-2x6 | 49,090 | 134,385 | 112,780 | 94,765 | 80,165 | 68,405 | |
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Solid Lumber Sizes | |||||||
---|---|---|---|---|---|---|---|
Framing | Lumber Size (each side of Rod) |
Allow. Perp. To Grain, Pc (lbs.) |
Allowable Parallel to Grain, Pc (lbs.) | ||||
Plate Height (ft) | |||||||
8 | 9 | 10 | 11 | 12 | |||
(160) | (160) | (160) | (160) | (160) | |||
4-inch Wall | 1-2x4 | 4,255 | 5,485 | 4,355 | 3,540 | 2,925 | 2,460 |
1-3x4 | 7,090 | 9,145 | 7,260 | 5,895 | 4,875 | 4,100 | |
1-4x4 | 9,925 | 14,855 | 11,825 | 9,615 | 7,960 | 6,695 | |
2-3x4 | 14,175 | 18,285 | 14,525 | 11,790 | 9,755 | 8,200 | |
1-4x6 | 15,595 | 23,265 | 18,535 | 15,080 | 12,495 | 10,510 | |
1-4x8 | 20,555 | 30,550 | 24,370 | 19,840 | 16,440 | 13,835 | |
1-4x10 | 26,225 | 38,815 | 30,995 | 25,250 | 20,940 | 17,625 | |
2-4x6 | 31,185 | 46,530 | 37,075 | 30,160 | 24,985 | 21,020 | |
1-4x12 | 31,895 | 47,210 | 37,695 | 30,710 | 25,465 | 21,435 | |
2-4x8 | 41,110 | 61,105 | 48,735 | 39,675 | 32,880 | 27,670 | |
6-inch Wall | 1-2x6 | 6,685 | 18,765 | 15,470 | 12,850 | 10,790 | 9,165 |
1-3x6 | 11,140 | 31,275 | 25,780 | 21,420 | 17,985 | 15,275 | |
1-4x6 | 15,595 | 49,610 | 41,300 | 34,525 | 29,110 | 24,785 | |
1-6x6 | 24,505 | 59,530 | 51,230 | 43,780 | 37,450 | 32,200 | |
1-6x8 | 33,415 | 79,455 | 68,780 | 59,030 | 50,640 | 43,625 | |
1-6x10 | 42,325 | 98,280 | 85,620 | 73,830 | 63,540 | 54,860 | |
1-6x12 | 51,235 | 118,970 | 103,645 | 89,370 | 76,920 | 66,410 | |
|
Multiple 2x Sizes | |||||||
---|---|---|---|---|---|---|---|
Framing | Lumber Size (each side of Rod) |
Allow. Perp. To Grain, Pc (lbs.) |
Allowable Parallel to Grain, Pc (lbs.) | ||||
Plate Height (ft) | |||||||
8 | 9 | 10 | 11 | 12 | |||
(160) | (160) | (160) | (160) | (160) | |||
4-inch Wall | 1-2x4 | 4,255 | 5,485 | 4,355 | 3,540 | 2,925 | 2,460 |
2-2x4 | 8,505 | 10,970 | 8,715 | 7,075 | 5,855 | 4,920 | |
3-2x4 | 12,760 | 16,455 | 13,070 | 10,615 | 8,780 | 7,380 | |
4-2x4 | 17,010 | 21,940 | 17,425 | 14,150 | 11,705 | 9,840 | |
5-2x4 | 21,265 | 27,430 | 21,785 | 17,690 | 14,630 | 12,295 | |
6-2x4 | 25,515 | 32,915 | 26,140 | 21,225 | 17,560 | 14,755 | |
7-2x4 | 29,770 | 38,400 | 30,500 | 24,765 | 20,485 | 17,215 | |
8-2x4 | 34,020 | 43,885 | 34,855 | 28,300 | 23,410 | 19,675 | |
9-2x4 | 38,275 | 49,370 | 39,210 | 31,840 | 26,340 | 22,135 | |
6-inch Wall | 1-2x6 | 6,685 | 18,765 | 15,470 | 12,850 | 10,790 | 9,165 |
2-2x6 | 13,365 | 37,535 | 30,935 | 25,700 | 21,585 | 18,325 | |
3-2x6 | 20,050 | 56,300 | 46,405 | 38,555 | 32,375 | 27,490 | |
4-2x6 | 26,730 | 75,065 | 61,875 | 51,405 | 43,165 | 36,655 | |
5-2x6 | 33,415 | 93,830 | 77,340 | 64,255 | 53,960 | 45,820 | |
6-2x6 | 40,095 | 112,600 | 92,810 | 77,105 | 64,750 | 54,980 | |
7-2x6 | 46,780 | 131,365 | 108,280 | 89,955 | 75,540 | 64,145 | |
|
Solid Lumber Sizes | |||||||
---|---|---|---|---|---|---|---|
Framing | Lumber Size (each side of Rod) |
Allow. Perp. To Grain, Pc (lbs.) |
Allowable Parallel to Grain, Pc (lbs.) | ||||
Plate Height (ft) | |||||||
8 | 9 | 10 | 11 | 12 | |||
(160) | (160) | (160) | (160) | (160) | |||
4-inch Wall | 1-2x4 | 5,930 | 5,905 | 4,700 | 3,820 | 3,165 | 2,660 |
1-3x4 | 9,890 | 9,845 | 7,835 | 6,370 | 5,275 | 4,435 | |
1-4x4 | 13,845 | 15,675 | 12,475 | 10,145 | 8,400 | 7,065 | |
2-3x4 | 19,775 | 19,690 | 15,670 | 12,740 | 10,550 | 8,870 | |
1-4x6 | 21,750 | 24,515 | 19,535 | 15,895 | 13,170 | 11,080 | |
1-4x8 | 28,675 | 32,230 | 25,700 | 20,925 | 17,340 | 14,590 | |
1-4x10 | 36,585 | 41,000 | 32,725 | 26,655 | 22,095 | 18,595 | |
2-4x6 | 43,505 | 49,030 | 39,070 | 31,795 | 26,340 | 22,160 | |
1-4x12 | 44,495 | 49,710 | 39,710 | 32,360 | 26,835 | 22,595 | |
2-4x8 | 57,350 | 64,455 | 51,405 | 41,845 | 34,680 | 29,180 | |
6-inch Wall | 1-2x6 | 9,325 | 19,810 | 16,470 | 13,755 | 11,590 | 9,865 |
1-3x6 | 15,535 | 33,020 | 27,445 | 22,925 | 19,315 | 16,440 | |
1-4x6 | 21,750 | 52,160 | 43,460 | 36,355 | 30,660 | 26,110 | |
1-6x6 | 34,185 | 60,045 | 53,640 | 47,195 | 41,220 | 35,950 | |
1-6x8 | 46,615 | 81,880 | 73,145 | 64,355 | 56,205 | 49,025 | |
1-6x10 | 59,045 | 103,715 | 92,650 | 81,520 | 71,195 | 62,100 | |
1-6x12 | 71,475 | 125,550 | 112,155 | 98,680 | 86,185 | 75,175 | |
|
Multiple 2x Sizes | |||||||
---|---|---|---|---|---|---|---|
Framing | Lumber Size (each side of Rod) |
Allow. Perp. To Grain, Pc (lbs.) |
Allowable Parallel to Grain, Pc (lbs.) | ||||
Plate Height (ft) | |||||||
8 | 9 | 10 | 11 | 12 | |||
(160) | (160) | (160) | (160) | (160) | |||
4-inch Wall | 1-2x4 | 5,930 | 5,905 | 4,700 | 3,820 | 3,165 | 2,660 |
2-2x4 | 11,865 | 11,815 | 9,400 | 7,645 | 6,330 | 5,325 | |
3-2x4 | 17,800 | 17,720 | 14,105 | 11,465 | 9,495 | 7,985 | |
4-2x4 | 23,730 | 23,630 | 18,805 | 15,290 | 12,660 | 10,645 | |
5-2x4 | 29,660 | 29,535 | 23,505 | 19,110 | 15,825 | 13,305 | |
6-2x4 | 35,595 | 35,440 | 28,205 | 22,935 | 18,990 | 15,970 | |
7-2x4 | 41,525 | 41,350 | 32,910 | 26,755 | 22,155 | 18,630 | |
8-2x4 | 47,460 | 47,255 | 37,610 | 30,580 | 25,320 | 21,290 | |
9-2x4 | 53,395 | 53,160 | 42,310 | 34,400 | 28,485 | 23,955 | |
6-inch Wall | 1-2x6 | 9,325 | 19,810 | 16,470 | 13,755 | 11,590 | 9,865 |
2-2x6 | 18,645 | 39,625 | 32,935 | 27,505 | 23,175 | 19,725 | |
3-2x6 | 27,965 | 59,435 | 49,405 | 41,260 | 34,765 | 29,590 | |
4-2x6 | 37,290 | 79,245 | 65,875 | 55,015 | 46,355 | 39,450 | |
5-2x6 | 46,615 | 99,055 | 82,340 | 68,770 | 57,945 | 49,315 | |
6-2x6 | 55,935 | 118,870 | 98,810 | 82,520 | 69,530 | 59,180 | |
7-2x6 | 65,255 | 138,680 | 115,280 | 96,275 | 81,120 | 69,040 | |
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Framing | Lumber Size (each side of Rod) | DF Sill Plate Allow Perp. To Grain Pc (lbs) | SP Sill Plate Allow Perp. To Grain Pc (lbs) | Allowable Parallel to Grain, Pc (lbs.) | ||||
---|---|---|---|---|---|---|---|---|
Plate Height (ft) | ||||||||
8 | 9 | 10 | 11 | 12 | ||||
(160) | (160) | (160) | (160) | (160) | ||||
4-inch Wall | 1-3 1/2x3 1/2 | 15,315 | 13,845 | 25,420 | 20,100 | 16,270 | 13,430 | 11,265 |
1-3 1/2x5 1/4 | 22,970 | 20,765 | 38,125 | 30,150 | 24,405 | 20,145 | 16,900 | |
1-3 1/2x7 | 30,625 | 27,685 | 50,835 | 40,200 | 32,540 | 26,860 | 22,535 | |
6-inch Wall | 1-5 1/4x3 1/2 | 22,970 | 20,765 | 79,445 | 64,540 | 53,015 | 44,150 | 37,255 |
1-5 1/4x5 1/4 | 34,455 | 31,145 | 119,170 | 96,805 | 79,520 | 66,220 | 55,885 | |
1-5 1/4x7 | 45,940 | 41,530 | 158,890 | 129,075 | 106,030 | 88,295 | 74,510 | |
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Parallam® is a registered trademank of Trus Joist® by Weyerhaeuser.
Framing | Lumber Size (each side of Rod) | DF Sill Plate Allow Perp. To Grain, Pc (lbs) | SP Sill Plate Allow Perp. To Grain, Pc (lbs) | Allowable Parallel to Grain, Pc (lbs.) | ||||
---|---|---|---|---|---|---|---|---|
Plate Height (ft) | ||||||||
8 | 9 | 10 | 11 | 12 | ||||
(160) | (160) | (160) | (160) | (160) | ||||
4-inch Wall | 1-3-1/2x3-1/2 | 15,315 | 13,845 | 18,110 | 14,380 | 11,670 | 9,645 | 8,105 |
1-3-1/2x5-1/4 | 22,970 | 20,765 | 27,160 | 21,570 | 17,505 | 14,470 | 12,155 | |
1-3-1/2x7 | 30,625 | 27,685 | 36,215 | 28,760 | 23,340 | 19,295 | 16,205 | |
6-inch Wall | 1-5-1/4x3-1/2 | 22,970 | 20,765 | 53,900 | 44,880 | 37,345 | 31,330 | 26,555 |
1-5-1/4x5-1/4 | 34,455 | 31,145 | 80,850 | 67,320 | 56,020 | 46,995 | 39,835 | |
1-5-1/4x7 | 45,940 | 41,530 | 107,805 | 89,760 | 74,695 | 62,655 | 53,110 | |
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