A multi-span beam roof structure replacing an old metal pavilion. 14' × 12' projection, 1:12 pitch, tinted/gray corrugated polycarbonate roof with 2-panel overlap, hidden roll-up shades, and exposed black decorative hardware throughout.
Plan, front, and side elevations — drawn to scale. Knee braces are an optional retrofit (the 3-post structure is stiff enough without them); they can be added later as decorative 2×6 gussets if you want to match the existing pavilion's look.
Plan · Front · SideLumber, structural hardware, fasteners, and accessories. With quantity, size, and an open price field you'll fill in once you have vendor quotes.
Lumber · Hardware · FastenersPlumb-cut angles for the rafter-to-4×12 connection, bird's-mouth geometry, decorative tail templates, and a complete per-piece cut list.
Angles · Templates · Cut listStep-by-step build sequence with safety procedures for the two highest-risk connections: anchoring to existing concrete and attaching to the existing 4×12 beam.
Sequence · Safety · QAWhat "tongue at 12, blade at 1" actually means, how a Speed Square works, what plumb/level/square is, rafter anatomy, Simpson connectors, anchor types, wood movement, code & permitting, and a full tool glossary.
Glossary · Techniques · Code| Dimension | Value | Notes |
|---|---|---|
| Outer post center-to-center (width) | 168 in. (14'-0") | Two 4×4 posts at 0" and 168"; middle post dead-center at 84" |
| Projection (face of 4×12 → new post CL) | 144 in. (12'-0") | Horizontal run; rafter length along slope ≈ 144.5" |
| Post height | 96 in. (8'-0") | Stock length; will be trimmed to suit hanger/sandwich stack-up |
| Existing 4×12 underside | 108 in. AFF | Floor to bottom of 4×12 — high reference for slope geometry |
| Roof pitch | 1:12 | 1" drop per 12" of run = 4.76° slope; 12" total drop over the 144" run |
| Beam overhang (each end) | 12 in. | 16' boards on 14' c-c span → 1' tail past each outer post |
| Rafter overhang (front tail, along slope) | 24 in. (2') | 16' stock cut to 14'-0½" finished; ~23½" waste per board. The 2' rafter tail is exposed wood past the polycarbonate panels (classic pergola look). |
| Rafter spacing | 21 in. o.c. | 9 rafters over 168" c-c outer. 2 panels per bay (78" upper + 79" lower, 12" overlap) cover with 1.5" bearing each side. |
| Shade opening (inside-to-inside, ×2) | 80.5 in. | Two symmetrical openings; 72" roller shades with 4.25" inset each side |
| Sandwich beam thickness | 6.5 in. | 1.5" + 3.5" (post) + 1.5"; 3.5" pocket between 2×8 inside faces for shade bundle |
| Connection | Hardware | Quantity |
|---|---|---|
| Post → concrete | Simpson APVB44 Avant post base + ⅝" concrete anchors (4 SDWS22312DBB + 4 STN22 per base) | 3 |
| Beam → post (sandwich) | Simpson Outdoor Accents SDWS 5-½" screw + STN22 hex washer | 12 screws (2/side × 3 posts × 2 sides) |
| Rafter → existing 4×12 (high) | Simpson LSSJ26 field-slopeable joist hanger (bent on-site to 1:12) | 9 |
| Rafter → new 2×8 beam (low) | Simpson H2.5A hurricane tie (uplift) | 9 |