Build three 2-ply 2x8 PT beams. Install in notched post tops. Bolt with (2) 1/2" x 6-1/2" bolts per post connection (plan says 6" minimum — buy 6-1/2", see hardware note below).
Beam Layout
Three beams run PERPENDICULAR to the pool, through each column of 3 posts:
LEFT column beam: connects pool-side-left → middle-left → back-left
RIGHT column beam: connects pool-side-right → middle-right → back-right
Each beam sits in NOTCHES on 3 posts and cantilevers 2'-0" past the outer posts on both ends. Total beam length ≈ 14'-8". See Phase 1 post grid diagram for the top-down layout.
Wait for cure: Do not install beams until concrete has cured at least 7 days.
Hardware for This Phase
Item
Quantity
Source
2x8 PT SYP at 14'
2 pieces
On hand (Bushka: BEAMS)
2x8 PT SYP at 16'
4 pieces
On hand (Bushka: BEAMS)
#10 wood screws, 2-1/2" long (exterior grade)
~100 (1 lb box)
NEED TO BUY
1/2" x 6-1/2" hex bolts (hot-dip galv)
18
NEED TO BUY — plan says 6" MINIMUM, but the bolt passes through 5-1/2" of wood; a 6" bolt leaves barely enough thread for washer + nut. 6-1/2" is the right buy.
1/2" drill bit (long enough to drill through 6x6 post + 3" beam = at least 9")
Ratchet with 3/4" socket (for 1/2" hex bolts)
4' or 6' level
Speed Square
Chalk line
360° laser level
Sawhorses (2)
Part A: Build the Beams (Ground Work)
Step 1: Cut Beam Members to Length
1Cut 2 pieces of 2x8 PT for each of the 3 beams (6 pieces total).
You have 4 pieces of 2x8×16' (Order #1) for 2 beams (2 plies × 2 beams = 4 pieces)
Plus 2 pieces of 2x8×14' (Order #1) for the third beam (2 plies × 1 beam = 2 pieces)
Target beam length after cutting: ~14'-8" (10'-8" post-to-post + 2'-0" cantilever each end)
The 16' pieces have plenty of length to cut down to 14'-8" (trim 1'-4")
The 14' pieces are 8" SHORT of a full 14'-8" beam. Options: (a) reduce that beam's cantilever to 1'-8" each side (total 14'), or (b) use asymmetric cantilevers (2' + 1'-4")
Use Speed Square for square cuts
Which beam gets the shorter 14' pieces? Use them for the MIDDLE column beam. That beam's ends are cantilevered but not near the deck corners, so slightly reduced cantilever is structurally fine. The OUTER two column beams (from 16' pieces) get the full 14'-8" length with full 2' cantilevers.
Step 2: Check for Crown
2Sight along each 2x8 to find its natural crown (bow).
Look along the length of the board from one end — you'll see a slight bow (concave on one edge, convex on the other)
The "crown" is the convex edge — the one that bows upward when the concave edge is down
Mark the crown side with an arrow pointing UP toward the crown
Both plies get installed with the crown facing UP
Over time, deck load will flatten the crown, leaving the beam straight rather than sagging
Step 3: Laminate the 2 Plies
Per A3.1 detail 02: "#10 WOOD SCREWS MIN. 2-1/2" LONG, STAGGERED IN 2 ROWS. 16" TYPICAL. 2 THREADED SCREWS AT EACH END."
3Screw the two 2x8s together face-to-face.
Lay both 2x8s face-to-face on sawhorses, both crowns pointing UP, top edges flush, ends flush
Chalk two horizontal lines down the length of the beam face:
Top row: 2" down from the top edge of the beam
Bottom row: 2" up from the bottom edge of the beam
(For a 7-1/4" tall 2x8, these two rows will be ~3-1/4" apart)
Mark screw positions along each row:
Top row: mark positions at 0", 16", 32", 48"... every 16" along the length
Bottom row: mark positions offset by 8" from the top row: 8", 24", 40", 56"... every 16"
The result is a zig-zag pattern — screws alternate between the two rows every 8"
Drive #10 x 2-1/2" screws at each marked position
At each end of the beam: 2 extra screws concentrated in the last 6" (one in top row, one in bottom row, closer together than the 16" spacing)
Beam laminated face-to-face. Row 1 at 2" from top, Row 2 at 2" from bottom. Screws every 16" per row, offset 8" so alternates every 8" along the beam. Extra pair at each end.
Count: ~11 screws per row × 2 rows = ~22 screws per beam + 4 end screws = ~26 per beam. Times 3 beams = ~78 screws total.
Part B: Install Beams on Posts
Step 4: Lift Beam Onto Posts
4Lift each 2-ply beam onto the 3 notched posts of its column.
Two people minimum (beam weighs ~90 lbs)
Position beam so it drops into the notches on all 3 posts
Beam bottom rests on the notch shoulder (bottom of notch)
Beam ends extend 2'-0" past outer posts (pool-side and back)
Cantilever check: Measure from the outer post face to the end of the beam on both sides — should be 2'-0" (24") equal on each end. Slide the beam if needed before securing.
Step 5: Verify Beam Level
5Use laser or level to verify beam top is level along its length.
Sweep laser along the beam top
All 3 post positions should show the beam at the same elevation
Small variances (up to 1/8") can be shimmed with hardwood shims in the notch
Larger variances mean a post is at wrong height — address before bolting
Step 6: Drill and Bolt Beam to Each Post
Per A3.1 detail 01: "(2) 1/2" DIAMETER x 6" LONG (MIN.) BOLTS WITH WASHERS"
Left: top-down showing beam in the notch, bolts go through the back 2-1/2" of post + through the beam. Right: side view showing bolt positions — 2" from top and 2" from bottom of the beam.
Understanding the geometry: Because you notched the posts, the beam sits INSIDE a cutout in the top of each post. Looking down from above, the notch removed 3" of the post (making room for the beam), and 2-1/2" of post material remains behind the beam. The bolts pass through the remaining 2-1/2" of post material AND through the 3" thick beam — a total of 5-1/2" of material. That's why the buy list specifies 6-1/2" bolts: a 6" bolt (the plan's stated minimum) leaves only ~1/2" for the washer and nut, which is marginal; 6-1/2" gives a full inch of thread on the far side.
6At each post, drill and install 2 through-bolts.
Work on the "back side" of the post — the face opposite the notch opening, where the solid 2-1/2" of post material remains behind the beam
Mark bolt locations on this back face:
Top bolt: 2" down from the top edge of the beam
Bottom bolt: 2" up from the bottom edge of the beam
(Bolts end up about 3-1/4" apart vertically)
Drill a 1/2" hole all the way through: post material (2-1/2") then beam (3") = 5-1/2" total drilling per hole
Insert the 1/2" x 6-1/2" bolt from the back side of the post (bolt head on the outside)
The threaded end will come out through the front of the beam (into the notch cavity or beyond)
Add a washer, then thread the nut on the front side
Tighten with a 3/4" wrench — firm but not over-tightened (don't crush the wood)
Drill BOTH bolt holes at one post before inserting either bolt, then install both bolts together. This keeps the beam from shifting between drill operations.
Bit length: You need a 1/2" drill bit at least 9" long (or a 12" ship auger bit) to reach all the way through the post + beam and still have shank in the drill chuck. Standard 6" bits are too short.
Step 7: Repeat for All 3 Beams
7Install left, middle, and right column beams the same way.
Each beam gets 6 bolts total (2 per post × 3 posts). Total for all 3 beams: 18 bolts.
Part C: Verify Alignment
Step 8: Check Beams Parallel
8Measure between adjacent beams at multiple points.
Left beam to middle beam: should be about 60" (5'-0")
Middle beam to right beam: should be about 60"
Measure at pool-side end, middle, and back end of each beam
All measurements should match within 1/4"
Step 9: Verify Beam Tops at Same Elevation
9Use laser to verify all 3 beam tops are at the same level.
Any variance greater than 1/8" between beams means joists won't sit flat. Address by shimming beams or trimming posts before proceeding.
Completion Checklist
All 3 beams built as 2-ply 2x8 with staggered #10 screws (2 rows, 16" spacing)
2 additional screws at each end of each beam
Each beam installed in notches on 3 posts, resting on notch shoulder
Each beam has 2 × 1/2" x 6-1/2" bolts at each post connection
18 bolts total (6 per beam × 3 beams)
All bolts have washers on both sides and nuts
Cantilever equal on both ends of each beam (~2'-0" each)
All 3 beam tops at same elevation (verified with laser)
Beams parallel to each other (60" apart at multiple points)
Common Problems & Fixes
Beam doesn't sit level across 3 posts
Verify each post is the same height. If one post is 1/4" too tall, trim with Sawzall. If too short, shim with hardwood shim in the notch.
Cantilever isn't 2'-0" equal on both ends
Slide beam left or right in the notches to center it before bolting. If beam is too short overall, cantilever less on each end. If too long, trim off excess.
Beam won't drop into notch
Notch may be too shallow or narrow. Re-check dimensions (7-1/4" deep × 3" wide). Enlarge with chisel or Sawzall.
1/2" bolt is tight in hole
Use 9/16" drill bit instead of 1/2" for easier bolt insertion. Still holds securely.