// CODE SNIPPET

R507.5 Deck Beams

Residential Code 2018 of Kansas > 5 Floors > R507 Exterior Decks > R507.5 Deck Beams

JUMP TO FULL CODE CHAPTER

Maximum allowable spans for wood deck beams, as shown in Figure R507.5, shall be in accordance with Table R507.5. Beam plies shall be fastened with two rows of 10d (3-inch × 0.128-inch) nails minimum at 16 inches (406 mm) on center along each edge. Beams shall be permitted to cantilever at each end up to one-fourth of the allowable beam span. Deck beams of other materials shall be permitted where designed in accordance with accepted engineering practices.

TABLE R507.5
DECK BEAM SPAN LENGTHS^{a, b, g} (feet - inches)
SPECIES^c	SIZE^d	DECK JOIST SPAN LESS THAN OR EQUAL TO: (feet)
SPECIES^c	SIZE^d	6	8	10	12	14	16	18
Southern pine	1 — 2 × 6	4-11	4-0	3-7	3-3	3-0	2-10	2-8
	1 — 2 × 8	5-11	5-1	4-7	4-2	2-10	3-7	3-5
	1 — 2 × 10	7-0	6-0	5-5	4-11	4-7	4-3	4-0
	1 — 2 × 12	8-3	7-1	6-4	5-10	5-5	5-0	4-9
	2 — 2 × 6	6-11	5-11	5-4	4-10	4-6	4-3	4-0
	2 — 2 × 8	8-9	7-7	6-9	6-2	5-9	5-4	5-0
	2 — 2 × 10	10-4	9-0	8-0	7-4	6-9	6-4	6-0
	2 — 2 × 12	12-2	10-7	9-5	8-7	8-0	7-6	7-0
	3 — 2 × 6	8-2	7-5	6-8	6-1	5-8	5-3	5-0
	3 — 2 × 8	10-10	9-6	8-6	7-9	7-2	6-8	6-4
	3 — 2 × 10	13-0	11-3	10-0	9-2	8-6	7-11	7-6
	3 — 2 × 12	15-3	13-3	11-10	10-9	10-0	9-4	8-10
Douglas fir-larch^e, hem-fir^e, spruce-pine-fir^e, redwood, western cedars, ponderosa pine^f, red pine^f	3 × 6 or 2 — 2 x 6	5-5	4-8	4-2	3-10	3-6	3-1	2-9
	3 × 8 or 2 — 2 × 8	6-10	5-11	5-4	4-10	4-6	4-1	3-8
	3 × 10 or 2 — 2 × 10	8-4	7-3	6-6	5-11	5-6	5-1	4-8
	3 × 12 or 2 — 2 × 12	9-8	8-5	7-6	6-10	6-4	5-11	5-7
	4 × 6	6-5	5-6	4-11	4-6	4-2	3-11	3-8
	4 × 8	8-5	7-3	6-6	5-11	5-6	5-2	4-10
	4 × 10	9-11	8-7	7-8	7-0	6-6	6-1	5-8
	4 × 12	11-5	9-11	8-10	8-1	7-6	7-0	6-7
	3 — 2 × 6	7-4	6-8	6-0	5-6	5-1	4-9	4-6
	3 — 2 × 8	9-8	8-6	7-7	6-11	6-5	6-0	5-8
	3 — 2 × 10	12-0	10-5	9-4	8-6	7-10	7-4	6-11
	3 — 2 × 12	13-11	12-1	10-9	9-10	9-1	8-6	8-1

For SI: 1 inch = 25.4 mm, 1 foot = 304.8 mm, 1 pound per square foot = 0.0479 kPa, 1 pound = 0.454 kg.

Ground snow load, live load = 40 psf, dead load = 10 psf, L/Δ = 360 at main span, L/Δ = 180 at cantilever with a 220-pound point load applied at the end.
Beams supporting deck joists from one side only.
No. 2 grade, wet service factor.
Beam depth shall be greater than or equal to depth of joists with a flush beam condition.
Includes incising factor.
Northern species. Incising factor not included.
Beam cantilevers are limited to the adjacent beam's span divided by 4.

R507.5.1 Deck Beam Bearing

The ends of beams shall have not less than 1¹/₂ inches (38 mm) of bearing on wood or metal and not less than 3 inches (76 mm) of bearing on concrete or masonry for the entire width of the beam. Where multiple-span beams bear on intermediate posts, each ply must have full bearing on the post in accordance with Figures R507.5.1(1) and R507.5.1(2).

FIGURE R507.5.1(1)
DECK BEAM TO DECK POST

FIGURE R507.5.1(2)
NOTCHED POST-TO-BEAM CONNECTION

R507.5.2 Deck Beam Connection to Supports

Deck beams shall be attached to supports in a manner capable of transferring vertical loads and resisting horizontal displacement. Deck beam connections to wood posts shall be in accordance with Figures R507.5.1(1) and R507.5.1(2). Manufactured post-to-beam connectors shall be sized for the post and beam sizes. Bolts shall have washers under the head and nut.