Install rim joists on the LEFT and RIGHT sides to tie the joist ends together. Kerf-cut a 2x8 to follow the pool's curve for the pool-side rim. The back edge uses the outermost joist itself (no separate back rim needed). Add blocking per plan.
Understanding the layout: Because joists run parallel to the pool (in the WIDTH direction), the joist ENDS are on the LEFT and RIGHT sides of the deck. Those two sides need rim joists to tie the joist ends together and hold everything square. The FRONT (pool side) and BACK edges run PARALLEL to the joists — the outermost joist on each side essentially IS the rim for that edge. The pool side gets an additional kerf-cut 2x8 fastened to the front-most joist to form the curved edge.
Rim Joist Layout
Top-down. LEFT/RIGHT rims run perpendicular to joists (~14'-8" long each, from 16' stock). CURVED rim on pool side is kerf-cut from a 15' piece (16' stock trimmed). BACK edge is the back-most joist itself.
Blocking: Per A1.0 detail 02, provide 2x8 wood blocking at 12" OC between the pool-side (front-most) joist and the curved rim joist. These short pieces support the curved rim's kerfed back face. Since the curve varies, block lengths vary too (a few inches at deck edges, less at the pool's closest point).
Edge
Material
Length
Purpose
Left side (straight)
2x8 PT
16 ft
Ties all joist ENDS together on the left side (perpendicular to joists)
Right side (straight)
2x8 PT
16 ft
Ties all joist ENDS together on the right side (perpendicular to joists)
Pool side (curved)
2x8 PT — kerf cut
15 ft (from a 16' piece)
Fastened to the outer face of the front-most (pool-side) joist, kerf-cut to follow the pool curve
Back edge
Uses the back-most joist itself
—
No separate rim needed; the back-most 14' joist serves this function
Blocking behind curved rim at 12" OC per A1.0 (length varies with pool curve — cut on-site)
PL Premium exterior adhesive
3 tubes
For kerf cuts on curved section
3" structural screws (SDWS22 or GRK RSS)
1 lb
Rim-to-joist connections
Part A: Install Straight Rim Joists (Left & Right)
Step 1: Left Rim Joist
1Install one 16' 2x8 along the LEFT side of the deck.
Position it vertically (2x8 on edge, 7-1/4" tall side facing up), running along the entire left edge of the deck (perpendicular to the joists)
The rim covers the left END of every joist — flush against all ~15-16 joist ends
Top edge of rim flush with the top of the joists
Drive 2 structural screws (3" GRK RSS or SDWS22) through the rim into each joist's end grain
Step 2: Right Rim Joist
2Install one 16' 2x8 along the RIGHT side of the deck.
Same as the left rim, but on the right side
Covers the right END of every joist
Top edge flush with joist tops
2 structural screws per joist end
The left and right rims should end up parallel to each other and perpendicular to the joists. Measure diagonals of the framed rectangle (corner to corner) to verify square — both diagonals should match within 1/4".
Part B: Curved Pool-Side Rim Joist
The curved rim joist follows the pool's 24' diameter at a 1" offset from the coping.
Step 3: Kerf Cuts on the 15' 2x8
Per A1.0 detail 02:
Spec
Value
Kerf spacing
1/2" between adjacent kerfs
Kerf depth
1-1/4" (leaves 1/4" material behind)
Total kerfs for 14' of curve
~336 cuts
Left: straight board with parallel kerf cuts spaced 1/2" apart, cut 1-1/4" deep into a 1-1/2" thick board. Right: same board bent into a curve. Kerfs face the pool; the smooth 1/4" outer skin becomes the visible curve.
3Kerf-cut the 15' 2x8.
Lay 2x8 on sawhorses, kerf side UP
Set circular saw to 1-1/4" cut depth
Cut a spacer block exactly 1/2" wide
Cut first kerf perpendicular to board length
Place spacer against fresh cut, position saw against spacer for next cut
Repeat 300+ times
Only kerf the section that follows the curve (~14 feet)
Kerfs go on the CONCAVE side (facing the pool). When bent, kerfs close up. Back side (with 1/4" intact material) forms the smooth outer curve.
Test-bend a 3-foot scrap first. If it doesn't bend enough, decrease kerf spacing. If too flimsy, decrease depth.
Step 4: Apply Adhesive to Kerfs
4Squeeze a thin bead of adhesive into each kerf slot.
Work in sections you can install within 10 minutes (~4 feet at a time)
PL Premium Exterior or similar construction adhesive
Just enough to coat the kerf walls — when the kerf closes up during bending, the adhesive spreads to fill
Don't fill all ~336 kerfs at once — adhesive skins over before you can bend
3 tubes should be plenty for the full curved rim
Step 5: Cut and Install Blocking Behind the Curve
Physical reality of the curve: The pool sits behind the deck. The pool's curve bulges toward the deck at the center of the width and tapers back at the edges. The front-most joist is a STRAIGHT board parallel to the pool. So the space between the front-most joist and where the curved rim needs to sit VARIES — smallest at the deck's center, largest at the edges. Blocking pieces fill this varying gap, providing solid backing for the curved rim.
5Mark curved rim positions and cut blocking to fit.
Along the front-most joist, mark tick marks every 12" (from left to right)
At each tick mark, measure from the front face of the joist STRAIGHT OUT toward the pool, until you're at 1" from the pool coping
That measurement = the length of the blocking piece at that position
Cut a 2x8 scrap to that length
Screw one end of the block to the front of the front-most joist (2 × 3" screws)
Repeat at every 12" tick mark across the 14' pool-side edge (~14 blocks total)
The block ends form a "curved outline" pointing toward the pool — the curved rim will attach to those ends
Block lengths will vary — could be as short as ~2" near the deck's center and up to ~1'-6" near the deck's edges. Measure each individually. Don't assume uniform length.
Step 6: Bend the Rim Onto the Blocks
6Bend the kerfed 2x8 against the exposed ends of the blocks, following the pool curve at 1" from the coping.
Two people — one bends and holds, one screws
Squeeze a thin bead of PL Premium into each kerf slot BEFORE bending (work 4' at a time)
Start at one end of the pool-side edge (say pool-side-LEFT corner)
Screw the rim into the end of the LEFT rim joist first (corner connection)
Bend the rim to touch the next block over
Screw through the rim into that block (2 × 3" structural screws)
Continue bending, contacting each block, and screwing across the 14'
End at the pool-side-RIGHT corner, screwing into the RIGHT rim joist
The 1/4" material behind each kerf forms the smooth outer curve; the kerf slots close up on the inside against the blocks
Verify pool offset with tape at multiple points — should be about 12'-1" from pool center everywhere (12' pool radius + 1" gap).
Part C: Verify Curved Rim Geometry
Step 7: Check Pool-to-Rim Distance at Multiple Points
7Measure from pool wall to rim joist at multiple points along the curve.
Every 2 feet along the curve
Should be consistent (about 1" gap)
+/- 1/4" variance is fine
Completion Checklist
Left rim (16' 2x8, straight) installed against left ends of all joists
Right rim (16' 2x8, straight) installed against right ends of all joists
Frame is square (diagonals match)
Variable-length 2x8 blocking installed at 12" OC along front-most joist (~14 blocks)
Curved pool-side rim kerf-cut, adhesive applied, bent against blocks and screwed at 1" pool offset
Curved rim also screwed into left/right rim joists at both corners
Pool offset consistent (~1" throughout, verified with tape)
About Fascia on the Curved Section
The plan material list includes 1x10 PT fascia for the STRAIGHT edges (back, left, right). The pool-side curved rim doesn't need fascia — it's not visible (tucked between pool and deck edge with Trex overhang).
The plan RIM JOIST/FASCIA DETAIL shows kerf specs for fascia in case it's wanted, but it's optional. Straight fascia gets installed later (after decking).
Common Problems & Fixes
Curved rim won't bend enough
Kerfs need to be closer (try 3/8") or deeper. Test on scrap first.
Curved rim snapped when bending
Kerfs too deep or bent too fast. Replace board, kerf 1-1/8" deep instead, bend slowly.
Curve isn't smooth — flat spots
Some kerfs didn't compress evenly. Add pressure at flat spots while adhesive is wet. Screw joist there to force curve.
Pool offset varies 1/2" to 2"
Joist ends not aligned with intended curve. Trim over-long joists shorter or accept curve as-is.