Shade-slat pergola plan

What the materials cost

Pressure-treated (Economy) and cedar above the posts (Durable), from the plan's own shopping list (12' x 12').

Plan specifications & limitations

• Rafter span

  2x8 at 16 in: at most 10' 7" (deck joist table, conservative for an open pergola)

  In this plan: 10' · Source: web-media.awc.org

• Rafter overhang

  At most 1' 7"

  In this plan: 1' · Source: web-media.awc.org

• Beam span

  3-2x10: at most 9' 1" (deck beam table, conservative)

  In this plan: 8' between posts · Source: web-media.awc.org

• Posts

  6x6 pressure-treated on uplift-rated post bases; 6x6 posts allow 14 ft (IRC Table R507.4)

  In this plan: 8' to the beams · Source: codes.iccsafe.org

• Knee braces

  Post bases alone do not stop a free-standing frame from rocking; braces at every post both ways

  In this plan: 4x4, 24 in legs, 1/2 in lag at each end · Source: Our design choice

• Uplift

  Every rafter tied to each beam; posts in uplift-rated post bases

  In this plan: Hurricane ties and post bases · Source: buildsite.com

• Footings

  At least 12 in below grade; frost protection not required for small free-standing accessory structures (local codes may still ask)

  In this plan: 16 in round, 36 in deep (deeper for uplift) · Source: codes.iccsafe.org

• Height

  Eave at most 10' for that exception

  In this plan: 8' under the beams · Source: codes.iccsafe.org

• Shade slats

  2x2 across the rafters, 1.5 in apart; rafters at 16 in

  In this plan: About half shade · Source: Our design choice

• Loads

  An open frame with no roof, sized with the deck tables (40 psf live + 10 psf dead), which is more than an open pergola carries. Check local snow, wind and frost depth with your building department. Frost depth varies by location: check your local code before you dig.

• No roof, no extra loads

  Do not add a solid roof, a swing, a hammock or hanging planters heavier than a few pounds: the plan is not sized for them.

• Wind and uplift

  Uplift-rated post bases, a hurricane tie on every rafter and knee braces at every post. In high-wind areas, ask your building department.

• Footings

  Round concrete footings on undisturbed soil, 36 in deep; local frost depth may ask more. Never bolt the posts to an existing patio slab.

• Permits and HOA

  Many cities and counties require a permit for structures above 120 sq ft. Some require one for smaller ones. Many places need a permit for a deck or a pergola; HOA rules may limit size, height or color. Checking permits, setbacks and HOA rules is your responsibility.

• Not an engineered plan

  The plan is a general guide built from published prescriptive tables. It is not stamped or engineered, and it is not a substitute for engineering or local approval.