255 18th Street — Roof Ventilation: Photos vs. Approved Plan
As-built roof vents (Sept 30, 2026) cross-referenced to approved mechanical sheet M-006.01 (Levin Engineering; DOB-approved 10/23/2024). Roof is a tenant amenity → strict vent rules apply.
① Vent height — §903.1
On an amenity roof, vents must terminate ≥ 7 ft (84″) above the roof (not the 24″ minimum). Measured: 28″ → fails.
On an amenity roof, vents must terminate ≥ 7 ft (84″) above the roof (not the 24″ minimum). Measured: 28″ → fails.
② Vent vs. opening — §903.5
No vent within 10 ft (120″) of a door / operable window / air intake unless it is ≥ 3 ft above that opening. Door = 138″ → OK; intakes = TBD.
No vent within 10 ft (120″) of a door / operable window / air intake unless it is ≥ 3 ft above that opening. Door = 138″ → OK; intakes = TBD.
③ Air intake — Mech §401.4
Outdoor-air intakes must be ≥ 10 ft from a plumbing vent, or the intake ≥ 3 ft below it. Corridor louver + condensers = measure.
Outdoor-air intakes must be ≥ 10 ft from a plumbing vent, or the intake ≥ 3 ft below it. Corridor louver + condensers = measure.
Approved roof plan — M-006.01, with the callouts to measure to
1Corridor fresh-air / exhaust louver (Greenheck ESD-435) — MEASURE each vent → here
2Elevator shaft + Class-1 motorized fire damper (normally closed)
3Rooftop condenser array (AC-1…AC-4) — MEASURE vent → intakes
4Roof access / metal stairs up (amenity roof → 7-ft vent rule)
524″ parapet + 18″ railing (per plan)
6Polypropylene vent / fresh-air risers (3″)
Priority measurements: height of the tallest vent (confirm none reaches 84″); and horizontal distance from the vent bank to ① the corridor fresh-air louver, ③ the nearest condenser intake, and any operable window. Marker positions are approximate, per the plan callouts.
The roof, photographed — what each shows
EXIT / bulkhead door — 138″ away = OK per §903.5
Condenser intakes near vents — measure
15:58
Risers beside the bulkhead wall with the condenser bank; the EXIT/bulkhead door is the opening we measured to.
Rusted stub — identify
Short vent risers — measure tallest vs 84″
16:01
Tall polypropylene risers; a lone rusted stub sits on its own flashing pad; condensers upper-right.
Varying heights — none confirmed ≥ 84″ (7 ft)
16:05
The vent bank on Unistrut — clearly varying heights, open goosenecks, several bare ends.
Rusted pipe, tape + mesh patch — identify: vent or gas/boiler flue?
16:05
Rusted pipe patched with black tape and mesh at the base — not a code-compliant termination or repair.
Open vent end (no birdscreen) — low
Condenser intake — measure
16:10
Single riser turning down at a 90° elbow beside the condensers; ERV-type unit and stair behind.
Rusted open pipe — identify (abandoned / vent / gas flue?)
16:11
Close-up: badly corroded open pipe with a clamp band; white object is a Wi-Fi dish (telecom, ignore).