Symmetrical Compression Posts
Compression Posts
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 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. Simpson Strong-Tie offers guidance by providing standard tables for compression elements. Find more information on our website.
Symmetrical Posts
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.

Compression Member Selection
Solid Lumber Sizes | |||||||
---|---|---|---|---|---|---|---|
Framing | Lumber Size (each side of rod) |
Allow. Perp. to Grain, Pc (lb.) |
Allowable Parallel to Grain, Pc (lb.) | ||||
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 | |
|
Multiple 2x Sizes | |||||||
---|---|---|---|---|---|---|---|
Framing | Lumber Size (each side of rod) |
Allow. Perp. to Grain, Pc (lb.) |
Allowable Parallel to Grain, Pc (lb.) | ||||
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 | |
|
Solid Lumber Sizes | |||||||
---|---|---|---|---|---|---|---|
Framing | Lumber Size (each side of rod) |
Allow. Perp. to Grain, Pc (lb.) |
Allowable Parallel to Grain, Pc (lb.) | ||||
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 (lb.) |
Allowable Parallel to Grain, Pc (lb.) | ||||
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 | |
|
Solid Lumber Sizes | |||||||
---|---|---|---|---|---|---|---|
Framing | Lumber Size (each side of rod) |
Allow. Perp. to Grain, Pc (lb.) |
Allowable Parallel to Grain, Pc (lb.) | ||||
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 (lb.) |
Allowable Parallel to Grain, Pc (lb.) | ||||
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 (lb.) |
Allowable Parallel to Grain, Pc (lb.) | ||||
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 (lb.) |
Allowable Parallel to Grain, Pc (lb.) | ||||
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 | |
|
Framing | Lumber Size (each side of rod) | DF Sill Plate Allow Perp. to Grain Pc (lb.) | SP Sill Plate Allow Perp. to Grain Pc (lb.) | Allowable Parallel to Grain, Pc (lb.) | ||||
---|---|---|---|---|---|---|---|---|
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 | |
|
Parallam® is a registered trademark of Trus Joist® by Weyerhaeuser.
Framing | Lumber Size (each side of rod) | DF Sill Plate Allow Perp. to Grain, Pc (lb.) | SP Sill Plate Allow Perp. to Grain, Pc (lb.) | Allowable Parallel to Grain, Pc (lb.) | ||||
---|---|---|---|---|---|---|---|---|
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 | |
|