Patio cover designer
Size
Size the patio cover.
16 by 12 ft, ledger at 10'-0"
The roof hangs from a ledger on the house and slopes down to a beam on 3 posts. With this slope the beam sits 7'-0-3/4" above the patio and the eave at 7'-10-1/4". Keep the ledger below your soffit and gutter.
Roof
Roofing and slope.
Shingles, 2 in 12
18'-0" by 13'-0-3/4" of roof, 235 sq ft on the slope. Below 4 in 12 shingles go on two layers of underlayment.
House side
Where the ledger fastens to the house.
2x8 ledger on the band joist or header
2x8 ledger, 12 lag screws at 20 in, flashed. Confirm the band joist or header is there at this height.
Posts
Posts and footings.
3 6x6 posts, on bases
3 footings, 24 in across, 48 in down, 1,024 lb uplift per post.
Beam
The beam and the lumber.
3-2x8, on top of the posts
OK, 49% used (bending, sliding snow case)
Rafters
Rafters.
2x6 at 16 in
OK, 80% used (bending, sliding snow case). 15 rafters, 13'-1-1/2" long, in slope-adjustable hangers on a 2x8 ledger.
Loads
Snow, wind and the ground.
20 psf snow, 115 mph wind
The snow load and wind speed start at 20 psf and 115 mph. Enter the values your building department gives. Roof snow 20.0 psf, 5.6 psf sliding off the house, a 15 psf drift at the wall, 1,024 lb uplift per post.
Assumptions
The house roof, the loads and the headroom this plan is drawn for. Use the values your building department gives.
- House roof
- Eave over the cover, 6 in 12, shingles30'-0" eave to eave, roof edge 2'-0" above the ledger. These set the snow that slides off the house and drifts at the wall.
- Snow used
- 20 psf on the ground, 20.0 psf on the coverplus 5.6 psf sliding off the house roof, and a 15 psf drift at the wall.
- Wind used
- 115 mph, exposure B1,024 lb uplift per post, which sizes the footings and the post bases.
- Headroom
- 7'-0-3/4" under the beamClears a standard 6'-8" door with room for a fan or a hanging light.
Drag to turn the patio cover · Scroll or pinch to zoom · Drag a handle to resize · Click a post, the beam, a rafter or the roof to change it