text.skipToContent text.skipToNavigation

Symmetrical Compression Posts

Compression Members: General Notes

  1. Studs, posts and blocking details are specified by the Designer and are not shipped with the Anchor Tiedown System.
  2. With the Anchor Tiedown System, it is not necessary to design the lumber in tension. See the Compression Member Selection Tables for compression member allowable capacities and additional design assumptions.
  3. The compression capacity of the lumber listed in the tables are based on the 2005 National Design Specification (NDS) for the plate heights, wall plate and compression member species specified.
  4. Wall plates and stud species are assumed to be the same as specified in the Compression Member Selection Tables (UNO). The Designer must review the compression members for variation of species, or unsupported heights other than those listed in the tables.
  5. Allowable perpendicular to grain stress for D.Fir-L lumber based on 625 psi, Southern Pine lumber based on 565 psi, Spruce-Pine-Fir lumber based on 425 psi, and Hem-Fir lumber based on 405 psi. Parallam lumber based on 625 psi or 565 psi as it will bear on solid sawn lumber.
  6. 2x and 3x based on # 2 grade, 4x and 6x lumber based on #1 grade.
  7. Bearing area factor Cb not included in lumber values.
  8. Perpendicular to grain capacities listed in the Compression Member Selection Tables may be multiplied by Cb for bearings not nearer than 3" to the end of the horizontal member. T is the width of the compression member.

    comp-members_note8

  9. Effective length of lumber (le) equal to plate height, less (3) 2x wall plates (i.e. 4½").
  10. Capacities shown, assume Ke = 1.0.

Compression Member Selection

Compression Post Perpendicular and Parallel to Grain Allowable Loads for Douglas Fir-Larch (Solid Lumber Sizes)
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 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
  1. See Compression Members: General Notes for additional information.
  2. Shaded Cells are limited by Parallel to Grain loads.
Compression Post Perpendicular and Parallel to Grain Allowable Loads for Douglas Fir-Larch (Multiple 2x Sizes)
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 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
  1. See Compression Members: General Notes for additional information.
  2. Shaded Cells are limited by Parallel to Grain loads.
Compression Post Perpendicular and Parallel to Grain Allowable Loads for Spruce-Pine-Fir (Solid Lumber Sizes)
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
  1. See Compression Members: General Notes for additional information.
  2. Shaded Cells are limited by Parallel to Grain loads.
Compression Post Perpendicular and Parallel to Grain Capacities for Spruce-Pine-Fir (Multiple 2x Sizes)
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
  1. See Compression Members: General Notes for additional information.
  2. Shaded Cells are limited by Parallel to Grain loads.
Column Perpendicular and Parallel to Grain Allowable Loads for Hem-Fir (Solid Lumber Sizes)
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
  1. See Compression Members: General Notes for additional information.
  2. Shaded Cells are limited by Parallel to Grain loads.
Column Perpendicular and Parallel to Grain Capacities for Hem-Fir (Multiple 2x Sizes)
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
  1. See Compression Members: General Notes for additional information.
  2. Shaded Cells are limited by Parallel to Grain loads.
Compression Post Perpendicular and Parallel to Grain Allowable Loads for Southern Pine (Solid Lumber Sizes)
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
  1. See Compression Members: General Notes for additional information.
  2. Shaded Cells are limited by Parallel to Grain loads.
Compression Post Perpendicular and Parallel to Grain Allowable Loads for Southern Pine (Multiple 2x Sizes)
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
  1. See Compression Members: General Notes for additional information.
  2. Shaded Cells are limited by Parallel to Grain loads.
Column Perpendicular and Parallel to Grain Capacities for Parallam® PSL
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
  1. See Compression Members: General Notes for additional information.
  2. PSL Grade = 1.8E with Fc=2500 psi.
  3. Fc perp= 625 psi for Douglas-Fir Larch (DF) sill plate.
  4. Fc perp= 565 psi for Southern Pine (SP) sill plate.
  5. Shaded columns are limited by Parallel to Grain loads.

Parallam® is a registered trademank of Trus Joist® by Weyerhaeuser.

Column Perpendicular and Parallel to Grain Loads for LSL
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
  1. See Compression Members: General Notes for additional information.
  2. LSL Grade = 1.3E with Fc=1400 psi.
  3. Fc perp= 625 psi for Douglas-Fir Larch (DF) sill plate.
  4. Fc perp= 565 psi for Southern Pine (SP) sill plate.
  5. Shaded columns are limited by Parallel to Grain loads.