Asymmetrical 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.
Asymmetrical Posts
This arrangement means that a maximum of three built-up studs at the end of the wall and multiple number of studs at the opposite side of the Strong-Rod. This provides uniform anchor placement and consistent end-of-wall placement location at upper floor levels.

Nailing Example: (4) total closest compression members adjacent to rod: 2" o.c. edge nailing x 4 = 8" o.c. nailing to two closest studs, each side of rod.

Framing Member Size | Number of Studs | Compression Capacity for Douglas Fir-Larch #2 Grade | Compression Capacity for Hem Fir #2 Grade | COG FROM END OF WALL (in) | |||||||||||
---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
Perp. to Grain, Pc⊥ (lbs) | Parallel to Grain, Pc (lbs) (160) | Perp. to Grain, Pc⊥ (lbs) | Parallel to Grain, Pc (lbs) (160) | ||||||||||||
End | Interior | Nominal top plate height (ft) | Nominal top plate height (ft) | ||||||||||||
8 | 9 | 10 | 11 | 12 | 8 | 9 | 10 | 11 | 12 | ||||||
2x4 | 2 | 1 | 9,845 | 10,035 | 7,995 | 6,510 | 5,385 | 4,530 | 6,380 | 8,235 | 6,540 | 5,310 | 4,395 | 3,690 | 5.25 |
2 | 13,125 | 13,380 | 10,660 | 8,680 | 7,180 | 6,040 | 8,505 | 10,980 | 8,720 | 7,080 | 5,860 | 4,920 | 7.50 | ||
3 | 16,405 | 16,725 | 13,325 | 10,850 | 8,975 | 7,550 | 10,630 | 13,725 | 10,900 | 8,850 | 7,325 | 6,150 | 9.15 | ||
4 | 19,690 | 20,070 | 15,990 | 13,020 | 10,770 | 9,060 | 12,760 | 16,470 | 13,080 | 10,620 | 8,790 | 7,380 | 10.50 | ||
5 | 22,970 | 23,415 | 18,655 | 15,190 | 12,565 | 10,570 | 14,885 | 19,215 | 15,260 | 12,390 | 10,255 | 8,610 | 11.68 | ||
6 | 26,250 | 26,760 | 21,320 | 17,360 | 14,360 | 12,080 | 17,010 | 21,960 | 17,440 | 14,160 | 11,720 | 9,840 | 12.75 | ||
3 | 1 | 13,125 | 13,380 | 10,660 | 8,680 | 7,180 | 6,040 | 8,505 | 10,980 | 8,720 | 7,080 | 5,860 | 4,920 | 5.25 | |
2 | 16,405 | 16,725 | 13,325 | 10,850 | 8,975 | 7,550 | 10,630 | 13,725 | 10,900 | 8,850 | 7,325 | 6,150 | 7.35 | ||
3 | 19,690 | 20,070 | 15,990 | 13,020 | 10,770 | 9,060 | 12,760 | 16,470 | 13,080 | 10,620 | 8,790 | 7,380 | 9.00 | ||
4 | 22,970 | 23,415 | 18,655 | 15,190 | 12,565 | 10,570 | 14,885 | 19,215 | 15,260 | 12,390 | 10,255 | 8,610 | 10.39 | ||
5 | 26,250 | 26,760 | 21,320 | 17,360 | 14,360 | 12,080 | 17,010 | 21,960 | 17,440 | 14,160 | 11,720 | 9,840 | 11.63 | ||
6 | 29,530 | 30,105 | 23,985 | 19,530 | 16,155 | 13,590 | 19,135 | 24,705 | 19,620 | 15,930 | 13,185 | 11,070 | 12.75 | ||
2x6 | 2 | 1 | 15,470 | 33,090 | 27,690 | 23,220 | 19,605 | 16,725 | 10,025 | 28,155 | 23,205 | 19,275 | 16,185 | 13,740 | 5.25 |
2 | 20,625 | 44,120 | 36,920 | 30,960 | 26,140 | 22,300 | 13,365 | 37,540 | 30,940 | 25,700 | 21,580 | 18,320 | 7.50 | ||
3 | 25,780 | 55,150 | 46,150 | 38,700 | 32,675 | 27,875 | 16,705 | 46,925 | 38,675 | 32,125 | 26,975 | 22,900 | 9.15 | ||
4 | 30,940 | 66,180 | 55,380 | 46,440 | 39,210 | 33,450 | 20,050 | 56,310 | 46,410 | 38,550 | 32,370 | 27,480 | 10.50 | ||
5 | 36,095 | 77,210 | 64,610 | 54,180 | 45,745 | 39,025 | 23,390 | 65,695 | 54,145 | 44,975 | 37,765 | 32,060 | 11.68 | ||
6 | 41,250 | 88,240 | 73,840 | 61,920 | 52,280 | 44,600 | 26,730 | 75,080 | 61,880 | 51,400 | 43,160 | 36,640 | 12.75 | ||
3 | 1 | 20,625 | 44,120 | 36,920 | 30,960 | 26,140 | 22,300 | 13,365 | 37,540 | 30,940 | 25,700 | 21,580 | 18,320 | 5.25 | |
2 | 25,780 | 55,150 | 46,150 | 38,700 | 32,675 | 27,875 | 16,705 | 46,925 | 38,675 | 32,125 | 26,975 | 22,900 | 7.35 | ||
3 | 30,940 | 66,180 | 55,380 | 46,440 | 39,210 | 33,450 | 20,050 | 56,310 | 46,410 | 38,550 | 32,370 | 27,480 | 9.00 | ||
4 | 36,095 | 77,210 | 64,610 | 54,180 | 45,745 | 39,025 | 23,390 | 65,695 | 54,145 | 44,975 | 37,765 | 32,060 | 10.39 | ||
5 | 41,250 | 88,240 | 73,840 | 61,920 | 52,280 | 44,600 | 26,730 | 75,080 | 61,880 | 51,400 | 43,160 | 36,640 | 11.63 | ||
6 | 46,405 | 99,270 | 83,070 | 69,660 | 58,815 | 50,175 | 30,070 | 84,465 | 69,615 | 57,825 | 48,555 | 41,220 | 12.75 |
Framing Member Size | Number of Studs | Compression Capacity for Southern Pine #2 Grade | Compression Capacity for Spruce-Pine-Fir #1/#2 Grade | COG FROM END OF WALL (in) | |||||||||||
---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
Perp. to Grain, Pc⊥ (lbs) | Parallel to Grain, Pc (lbs) (160) | Perp. to Grain, Pc⊥ (lbs) | Parallel to Grain, Pc (lbs) (160) | ||||||||||||
End | Interior | Nominal top plate height (ft) | Nominal top plate height (ft) | ||||||||||||
8 | 9 | 10 | 11 | 12 | 8 | 9 | 10 | 11 | 12 | ||||||
2x4 | 2 | 1 | 8,900 | 8,865 | 7,050 | 5,730 | 4,740 | 3,990 | 6,695 | 8,790 | 7,020 | 5,715 | 4,725 | 3,975 | 5.25 |
2 | 11,865 | 11,820 | 9,400 | 7,640 | 6,320 | 5,320 | 8,925 | 11,720 | 9,360 | 7,620 | 6,300 | 5,300 | 7.50 | ||
3 | 14,830 | 14,775 | 11,750 | 9,550 | 7,900 | 6,650 | 11,155 | 14,650 | 11,700 | 9,525 | 7,875 | 6,625 | 9.15 | ||
4 | 17,800 | 17,730 | 14,100 | 11,460 | 9,480 | 7,980 | 13,390 | 17,580 | 14,040 | 11,430 | 9,450 | 7,950 | 10.50 | ||
5 | 20,765 | 20,685 | 16,450 | 13,370 | 11,060 | 9,310 | 15,620 | 20,510 | 16,380 | 13,335 | 11,025 | 9,275 | 11.68 | ||
6 | 23,730 | 23,640 | 18,800 | 15,280 | 12,640 | 10,640 | 17,850 | 23,440 | 18,720 | 15,240 | 12,600 | 10,600 | 12.75 | ||
3 | 1 | 11,865 | 11,820 | 9,400 | 7,640 | 6,320 | 5,320 | 8,925 | 11,720 | 9,360 | 7,620 | 6,300 | 5,300 | 5.25 | |
2 | 14,830 | 14,775 | 11,750 | 9,550 | 7,900 | 6,650 | 11,155 | 14,650 | 11,700 | 9,525 | 7,875 | 6,625 | 7.35 | ||
3 | 17,800 | 17,730 | 14,100 | 11,460 | 9,480 | 7,980 | 13,390 | 17,580 | 14,040 | 11,430 | 9,450 | 7,950 | 9.00 | ||
4 | 20,765 | 20,685 | 16,450 | 13,370 | 11,060 | 9,310 | 15,620 | 20,510 | 16,380 | 13,335 | 11,025 | 9,275 | 10.39 | ||
5 | 23,730 | 23,640 | 18,800 | 15,280 | 12,640 | 10,640 | 17,850 | 23,440 | 18,720 | 15,240 | 12,600 | 10,600 | 11.63 | ||
6 | 26,695 | 26,595 | 21,150 | 17,190 | 14,220 | 11,970 | 20,080 | 26,370 | 21,060 | 17,145 | 14,175 | 11,925 | 12.75 | ||
2x6 | 2 | 1 | 13,985 | 29,715 | 24,705 | 20,625 | 17,385 | 14,790 | 10,520 | 28,800 | 24,165 | 20,310 | 17,175 | 14,655 | 5.25 |
2 | 18,645 | 39,620 | 32,940 | 27,500 | 23,180 | 19,720 | 14,025 | 38,400 | 32,220 | 27,080 | 22,900 | 19,540 | 7.50 | ||
3 | 23,305 | 49,525 | 41,175 | 34,375 | 28,975 | 24,650 | 17,530 | 48,000 | 40,275 | 33,850 | 28,625 | 24,425 | 9.15 | ||
4 | 27,970 | 59,430 | 49,410 | 41,250 | 34,770 | 29,580 | 21,040 | 57,600 | 48,330 | 40,620 | 34,350 | 29,310 | 10.50 | ||
5 | 32,630 | 69,335 | 57,645 | 48,125 | 40,565 | 34,510 | 24,545 | 67,200 | 56,385 | 47,390 | 40,075 | 34,195 | 11.68 | ||
6 | 37,290 | 79,240 | 65,880 | 55,000 | 46,360 | 39,440 | 28,050 | 76,800 | 64,440 | 54,160 | 45,800 | 39,080 | 12.75 | ||
3 | 1 | 18,645 | 39,620 | 32,940 | 27,500 | 23,180 | 19,720 | 14,025 | 38,400 | 32,220 | 27,080 | 22,900 | 19,540 | 5.25 | |
2 | 23,305 | 49,525 | 41,175 | 34,375 | 28,975 | 24,650 | 17,530 | 48,000 | 40,275 | 33,850 | 28,625 | 24,425 | 7.35 | ||
3 | 27,970 | 59,430 | 49,410 | 41,250 | 34,770 | 29,580 | 21,040 | 57,600 | 48,330 | 40,620 | 34,350 | 29,310 | 9.00 | ||
4 | 32,630 | 69,335 | 57,645 | 48,125 | 40,565 | 34,510 | 24,545 | 67,200 | 56,385 | 47,390 | 40,075 | 34,195 | 10.39 | ||
5 | 37,290 | 79,240 | 65,880 | 55,000 | 46,360 | 39,440 | 28,050 | 76,800 | 64,440 | 54,160 | 45,800 | 39,080 | 11.63 | ||
6 | 41,950 | 89,145 | 74,115 | 61,875 | 52,155 | 44,370 | 31,555 | 86,400 | 72,495 | 60,930 | 51,525 | 43,965 | 12.75 |