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Asymmetrical Compression Posts

Strong-Rod Systems

Technical and Installation Notes
Strong Rod Literature
Why Continuous Rod Tiedown Systems
Anchor Tiedown System
Uplift Restraint Systems for Roofs

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.

Asymmetrical Posts

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.

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Compression Loads
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