🪜 Framing Plan

Mark the three post centerlines on the slab. Measure 168" between outer post centerlines (use a 25' tape, double-check by measuring the diagonal to confirm a 7'-12'-right-triangle layout). The middle post lands exactly at 84".

1. Snap chalk lines on the slab for the three post centerlines. Mark a perpendicular baseline 144" from the face of the existing 4×12 beam (measure from the beam face, not from the wall behind it). Where the baseline crosses each post line is the post center.
2. Set each APVB44 post base in position. Mark the anchor-hole center (single ⅝" hole in the center of the base's anchor tab).
3. Drill a ⅝" × 5" hole at each mark with a ⅝" SDS-Plus bit. Vacuum each hole clean.
4. Drop the wedge anchor (or Titen HD) in, place the washer and nut on top, and tighten the nut with a ⅞" socket. The wedge expands at the bottom of the hole as you torque. Torque to anchor-manufacturer spec (typically 80-100 ft-lb for ⅝" anchors in 3000 psi concrete).
5. Plumb the post base in both directions with a 4' level. Shim under the base if the slab is uneven — non-shrink grout (Quikrete FastSet) sets in 20 minutes and is ideal for bedding.
6. Let the grout / anchor cure per the manufacturer's spec (typically 24 hours for full strength, though light loads are fine after 2 hours).

First time drilling into concrete? See §5. Concrete anchors in the Carpentry 101 page for the Titen HD vs. wedge anchor comparison and the step-by-step drill sequence.

1. Pre-cut the three 4×4 posts to 92-⅝" finished length (matches the existing pergola's posts — same 1" standoff, same saddle depth, same stack-up).
2. Apply a bead of construction adhesive (PL Premium) on the bottom of each post where it bears on the post base. This prevents squeak and water ingress.
3. Stand the two outer posts first. Brace them with ratchet straps running to ground anchors or heavy objects. Plumb each post in both directions with a 6' level; check the 168" outer distance hasn't changed.
4. Stand the middle post. Re-check the 84" symmetry (42" each way from the middle to the outer posts).
5. Drive four Simpson SDWS22312DBB structural wood screws (each with a STN22 hex-head washer) through the post-base side flange into the 4×4 post. This is the structural connection — these are Simpson's required fasteners for the APVB44 (per their installation sheet). The screws are visible and decorative — that's the point of the Avant collection.

The two 2×8 beams sandwich the 4×4 posts. The front 2×8 is the visible street-side face; the back 2×8 sits against the 4×12. The 3.5" gap between them is the pocket that hides the rolled-up shade bundle.

1. Lift the back 2×8 first (it's the one closer to the existing 4×12). Rest it on temporary ledger boards screwed to the posts at the right elevation. Verify elevation with the laser: top of back 2×8 = post top − 1.5" (so the front 2×8 cap will sit flush at post top).
2. Clamp the back 2×8 to the posts. From inside the structure, drill 5/16" pilot holes through the 2×8 and into the post (3-½" deep embedment). Use the SDWS 5-½" screws with STN22 hex washers. Drive 2 screws per post intersection on the back-beam side.
3. Lift the front 2×8 (the visible street face). Rest on a second set of temporary ledgers at the post-top elevation. The top of the front 2×8 should be flush with the top of the post.
4. Drill and drive 2 more SDWS screws per post intersection through the front 2×8 into the post.
5. Total: 12 SDWS screws with STN22 washers (2 per side × 3 posts × 2 sides). All screws are visible from the front and sides — this is the "exposed black decorative hardware" look. Make sure the screws are seated squarely so the STN22 washers sit flat.

This is the second stop-and-verify gate — you're attaching structural hardware to an existing finished beam. Mistakes here are visible, permanent, and weaken the existing structure if not done correctly.

1. Bend all 9 LSSJ26 hangers to 4.76° (1:12) on the ground. Stack them and confirm all 9 have the same bend angle before going up.
2. → See §6. Field-bending a hanger in the Carpentry 101 page for the step-by-step with a reference gauge trick.
3. Mark the 9 rafter locations on the face of the 4×12: starting at one end, mark at 21" on center (r1, r2, r3, … r9). Verify the layout is symmetric: the middle hanger is centered on the 7' mark above the middle post.
4. For each location: hold the bent hanger flat against the 4×12 face. The top of the hanger should be ~5-⅝" below the top of the 4×12 (so the rafter top will sit 5-⅞" below the 4×12 top — see Cut Sheet §6).
5. Mark the nail-hole positions, then pre-drill pilot holes with a 1/8" bit to 1-½" depth. This is critical in older redwood or dense pressure-treated lumber — it prevents the hanger from splitting and the nails from bending.
6. Nail the hanger to the 4×12 using Simpson N10 (10d × 1-½") joist hanger nails. Fill every nail hole (typically 6-8 per hanger face).
7. Repeat for all 9 hangers. After all are installed, run a taut string across the hanger seats — they should all align on the same slope plane.

1. Pre-cut all 9 rafters per the Cut Sheet §2 & §3. Gang-cut them so the plumb cuts and bird's-mouths are identical. Use rafter #1 as a dry-fit template before cutting #2-9.
2. Start with rafter #1 (one end). Lift it into the LSSJ26 hanger on the 4×12. Let the bird's-mouth seat on the front 2×8. Verify the rafter is plumb in both directions — front-to-back (rafter should be vertical) and side-to-side (rafter should be at 90° to the 4×12 face).
3. Nail the high end into the hanger with 4 Simpson N10 nails (2 per side flange, angled toed-in). Don't drive them all the way yet — leave the nails ⅛" proud so you can adjust the rafter in the next step.
4. With rafter #1 in place, run a string line along the top edge from the high end of rafter #1 to where rafter #9 will land. The string gives you the slope plane reference for the rest of the rafters.
5. Install rafter #9 (the other end) using the same procedure. Now the slope is set by the two end rafters.
6. Install the remaining 7 rafters (#2 through #8), aligning each top edge to the string. Once aligned, finish nailing.
7. After all 9 rafters are nailed, double-check rafter spacing (21" o.c., measured face-of-rafter to face-of-rafter) before moving on.

The H2.5A wraps the rafter and the top of the 2×8 sandwich to lock the rafter down against wind uplift. It is the rafter's primary resistance to being peeled off the roof in a storm.

1. Slide one H2.5A over each rafter at the bird's-mouth location. The two side flanges go against the 2×8 sandwich sides; the top flange wraps over the rafter's bottom edge.
2. Nail the side flanges to the 2×8 first (4 nails: 2 per side), then nail the top flange to the rafter (1 nail). Use Simpson N8 (8d × 1-½") or the Simpson-specified fastener.
3. Verify each tie is snug — no daylight between the tie and the wood. A loose tie is a failed tie.

Each of the 9 rafter bays gets two 8' panels cut to ~78" and ~79" along the slope, overlapped 12" at the middle so water sheds downhill. The upper panel covers rafter position 0–78", the lower panel covers rafter position 66–145" (a 0.5" overlap onto the front 2×8 of the beam). The 2' rafter tail past the beam is exposed wood (decorative).

1. Apply a continuous bead of butyl sealing tape along the high-side edge where the upper panel meets the 4×12 face (1 long strip, ~14'). Press the L-flashing into the butyl and screw it to the 4×12 face (not to the rafters). The flashing sheds water over the panel high edge.
2. Cut all 9 upper panels to 78" and all 9 lower panels to 79". Mark each one to avoid mixing them up — the upper panel goes to the high side of the bay, the lower panel goes to the low side.
3. Install the upper panels first. They run perpendicular to the slope (i.e., up-the-slope) with the ribs vertical. Each panel covers one rafter bay (24" wide = 21" rafter space + 1.5" bearing on each adjacent rafter). Slide the upper edge of the upper panel up under the L-flashing.
4. Pre-drill EVERY screw hole with a bit 1/8" larger than the screw shank. Polycarbonate expands and contracts significantly with temperature — the oversized hole is what allows the panel to move without cracking. A snug hole is the #1 cause of polycarbonate failure.
5. Drive the polycarbonate screws (EPDM-washer) through the panel into the rafter. Don't overtighten — the EPDM washer should just barely compress, not bulge. A bulging washer has lost its seal.
6. Install foam closure strips at the top (high side, against the L-flashing) and bottom (low side, against the bird's-mouth) of every panel. These keep wind-driven rain and insects out of the panel ribs.
7. Install the lower panels, overlapping the upper panels by 12". The lower panel's upper edge sits ON TOP of the upper panel's lower edge — this is the key to water shedding. Secure the lower panel with screws into the rafter, just like the upper panel.
8. Add a foam closure strip at the overlap seam (between the two panels' meeting edges) if you want extra weather protection — recommended.
9. Install U-shaped end caps on the front (low) edge of every panel. A dab of silicone on the cap holds it on.

1. Mount the 80.5" 2×4 shade support blocks horizontally against the back side of the rear 2×8 beam (one block per opening, two blocks total). The top of each block should be at the desired top of the shade opening — typically at the very top of the 3.5" pocket between the front and back 2×8.
2. Pre-drill and screw the blocks to the back 2×8 from the outside (use 3" deck screws through the 2×8 into the block end-grain).
3. Mount the shade brackets to the underside of the rear 2×8 (or to the inside face of the posts, per the shade manufacturer's instructions). The brackets must allow the rolled-up shade bundle to recess into the 3.5" pocket and be hidden by the front 2×8 from street view.
4. Install the roller shades per the manufacturer's instructions. The wand operator should be on the post side (not the open side) so it doesn't catch on anything when the shade is fully extended.
5. Test extend and retract both shades. Verify the rolled-up bundle is fully recessed into the pocket and not visible from the street.

If you want shades on the SIDES of the structure (north and south faces) in addition to the front (east face), add horizontal side blocking now. This is a design idea that came from the AI renderings — the AI consistently added horizontal side beams even though the original spec didn't call for them, and on reflection those beams are useful as shade mounting points. Two more roller shades turn this from a 2-sided sun shield into a 3-sided outdoor room.

1. Cut two 2×4 or 2×6 side blocks per side: one runs along the top of the post-beam intersection on the side, the other runs along the bottom. The blocks are horizontal, parallel to the ground, and span the 12' depth of the new structure. They mount to the inside face of each side rafter (or to a small cleat screwed to each rafter).
2. Each shade opening on the sides should be 80.5" tall (matching the front opening for consistency). The shade rolls up into a pocket between the side rafter and the side block, or between the block and a small fascia board.
3. Mount the side shades per the manufacturer's instructions. The wand operator should be inside the structure (toward the back, near the pavilion) so it doesn't get in the way of traffic.
4. Side shades typically use the same 72" Coolaroo Sesame shades as the front, just mounted vertically on the side. The visible width is the 12' depth of the new structure, so the shades are wide-format. Verify the manufacturer's max-width spec — 72" is the standard Coolaroo width.

Final QA checklist

• All 9 rafters are at 21" o.c. (face-to-face) and the slope plane is flat across the run
• All 9 LSSJ26 hangers are fully nailed (no empty nail holes)
• All 9 H2.5A hurricane ties are snug against both the rafter and the 2×8
• All 12 SDWS screws + STN22 washers are tight and seated flat
• All 12 masonry anchors are torqued to spec (re-torque after 24 hours)
• All 3 posts are plumb in both directions
• Polycarbonate panels move freely in their screw holes (not pinched)
• Flashing at the high side is sealed with butyl tape and screwed to the 4×12 (not the rafters)
• Shade brackets are rigid; shades roll up and down smoothly; rolled-up bundle is hidden in the 3.5" pocket
• Water test: run a hose on the roof for 10 minutes. Check for leaks at the high-side flashing, at polycarbonate seams, and around the post bases. Address any leaks before the first rain.

Sealing & finishing

1. Sand any rough edges on the rafter tails and beam ends (80-grit, then 120-grit). Ease the exposed corners slightly — sharp 90° corners on rafter tails look amateurish and splinter.
2. Apply the exterior wood sealer/stain to all six faces of every visible piece: posts, beams (front face only — back is hidden), rafters (top, bottom, and tail-end). Two coats, 24 hours apart. Back-brush into end-grain especially at the post tops and rafter tail ends — end-grain absorbs 5-10x more finish than face-grain.
3. Touch up the SDWS screw heads and STN22 washers with a small brush if any sealer dripped on them.
4. Remove construction debris. Sweep the slab. Caulk the joint between the post base and the slab with a high-quality exterior caulk to prevent water pooling under the base.