HVAC ROOFTOP PLATFORM — BEAM PLACEMENT & REINFORCEMENT PLAN

72306 Canyon Lane, Palm Desert, CA 92260  |  Owner: Sheri Kane  |  Unit: Bosch 3-ton package (~500 lb)
SHOP DRAWING — FRAMING CONTRACTOR
Derived from: E. Kim Eng. & Design
Sheets S-2 / S-4 / SD-1 / SD-3, Calc 326-26
Engineer of Record: Eui S. Kim, P.E. S5138
Issued: 2026-05-31  |  FOR FIELD VERIFICATION

1 — PLAN VIEW: NEW PSL BEAMS & POSTS OVER EXISTING FAU LOCATION   Scale: ½″ = 1'-0″ (nominal — verify in field)

N EXISTING FLAT ROOF DECK (urethane foam over plywood over 2×8 RR) (E) 2×8 RR @ 16″ o.c. typ. BOSCH 3-TON PACKAGE UNIT ~500 lb · ≈47″×33″ ROOF PENETRATION (supply + return) (N) PSL 5¼″ × 7″ × 13′-7″ · 1.8E PARALLAM® — BEAM B1 (N) PSL 5¼″ × 7″ × 13′-7″ · 1.8E PARALLAM® — BEAM B2 P1 P2 P3 P4 Bearing wall below — verify continuous to fdn. Bearing wall below — verify continuous to fdn. ℄ (E) FAU / DUCT CHASE 13′-7″ (BEAM LENGTH — OUT TO OUT) 13′-0″ CLEAR SPAN BETWEEN POSTS 3½″ BRG. (typ.) 4′-0″ C/C BEAM SPACING 16″ o.c. A A B B PLAN — ROOFTOP HVAC PLATFORM REINFORCEMENT Beams run perpendicular to existing 2×8 rafters · platform centered over existing FAU/duct chase LEGEND New PSL beam (B1, B2) New 4×6 DF #2 post (P1–P4) HVAC unit footprint (above) Bearing wall below (verify) Centerline / section cut

MEMBER SCHEDULE

MarkMemberQtyLength
B1, B2 5¼″ × 7″ 1.8E Parallam® PSL 2 13′-7″ ea.
P1–P4 4×6 DF No.2 4 9′-0″ ea.

CONNECTION SCHEDULE

LocationConnector
Beam-to-post (top) Simpson CCQ column cap, U.N.O. (see SD-1 / detail 5)
Post-to-plate (base) Simpson PBS post base — or A35 if on 2×6 sill (SD-1 / 5)
Lateral strap, beam ⇄ post Simpson MSTA18 strap (SD-1 / 4)
Beam to (E) rafter blocking Simpson A35 @ 16″ o.c. each side (SD-3 / 38, 43)
Solid blocking at supports 2×8 blocking full-depth between (E) rafters @ each end of beams (SD-1 / Note 3)
Fasteners (treated lumber) Hot-dip galv. ASTM A153 Cl. G185 (SN1 / Note 15)

DESIGN LOADS (per calc, pg. 26)

Roof DL25 psf · Roof LL: 20 psf
Trib. width / beam4′-0″
HVAC unit weight500 lb (Bosch 3-ton package)
Concentrated load350 lb @ 3′ from B1 end (compressor side)
Beam reaction (each end)761 lb DL + 543 lb LL = 1,304 lb factored
Post utilization14 % compression (passes by >7×)

2 — SECTION A-A: LONG SECTION THROUGH BEAM B1   Scale: ¾″ = 1'-0″ (nominal)

TOP OF (E) WALL PLATE — interior ceiling level (E) BRG. WALL (E) BRG. WALL (E) 2×8 ROOF JOISTS / RAFTERS (E) Foam roofing (E) Plywood deck P1 · 4×6 DF #2 P2 · 4×6 DF #2 (N) PSL 5¼″ × 7″ × 13′-7″ — BEAM B1 CCQ cap CCQ cap PBS base PBS base MSTA18 strap (each side of beam, both ends) Solid 2×8 blocking (full depth) between (E) rafters @ each post BOSCH 3-TON PACKAGE UNIT (above) — on platform/curb 13′-0″ CLEAR SPAN 3½″ post = 9′-0″ unbraced (per calc — verify field height) SECTION A-A

3 — GENERAL FRAMING NOTES

  1. Authority: All work per E. Kim Eng. structural plan set (sheets C-1, SN1, SN2, S1.0, S-2, S-3, S-4, SD-1, SD-2, SD-3) and calc package 326-26 dated 3/26/2026. This sheet is an interpretive placement aid only — engineer's drawings govern in any conflict.
  2. Verify in field: Locate the existing FAU duct chase and lay the platform centerline directly on it so the new package unit lines up with the existing supply/return penetration. Confirm 4′-0″ C/C beam spacing matches the Bosch unit's curb dimensions before cutting.
  3. Bearing path: Posts P1–P4 must land directly over continuous bearing walls that run all the way to foundation. Do not set a post on top plate alone if no wall is below.
  4. Roof deck cut-out: Cut the roof deck only after beams + posts are in place and blocking is installed. Do not cut existing rafters; if a rafter must be interrupted for the duct penetration, double-header per SD-2 detail 20 (typical opening in roof or wall).
  5. Blocking: Install full-depth 2×8 solid blocking between existing rafters at both ends of each beam (under P1, P2, P3, P4), tight to the underside of the deck. Toe-nail per SN1 nailing schedule.
  6. Beam orientation: PSL strong axis vertical. Beams run perpendicular to existing 2×8 rafters so they pick up multiple rafters via blocking. Top of beam = top of HVAC platform.
  7. Connections: Simpson hardware per schedule above. Equivalent ICC-listed hardware allowed only with engineer's written approval (SN1, Note 14).
  8. Fastener corrosion: Any fastener into pressure-treated lumber: hot-dip galv. (ASTM A153 Class G185), stainless, silicon bronze, or copper (SN1, Note 15).
  9. Curb & flashing: Frame an 8″ min. stucco/foam curb around the unit perimeter for waterproofing (per roof plan Section E). Roofing contractor flashes after framing inspection.
  10. Future solar: Owner plans PV panels on remaining flat roof areas. This reinforcement does not include solar dead/live loads on the HVAC platform itself. Solar layout to avoid the platform footprint and the duct penetration.
  11. Inspection holds: Frame inspection required before deck is cut and before unit is set. Engineer should observe the beam bearing condition prior to closing the roof.
Drawing prepared by Cowork as a placement aid for the framing contractor. Not a substitute for the engineer's sealed drawings. Reference Engineer of Record: Eui S. Kim, P.E. (CA S5138), E. Kim Eng. & Design, (818) 321-4243.