Commercial Roof Coating Wholesale District: Restoration & Cost

Step 1: Pre-Coating Inspection and Moisture Survey

1. Visual walk: document seams, penetrations, drains, flashings, and ponding zones with date stamped photos.
2. Infrared scan: performed after sunset on a dry day to locate wet insulation. Any zone above 15% moisture content is cut out and replaced, not coated over.
3. Core samples: minimum two per 10,000 sq ft, taken through the membrane to the deck to verify insulation condition.
4. Adhesion test: a 2 ft by 2 ft trial patch of the proposed coating, pulled at 24 and 72 hours to confirm bond strength above 2.0 psi.
5. Report: written findings with square footage of repair work, estimated coating gallons, and a go or no go recommendation.

A proper inspection takes 2 to 4 hours per 20,000 sq ft. We pair this with our commercial roof inspection protocol to document baseline condition before any product touches the membrane.

Step 2: Substrate Preparation

1. Power wash: 3,000 psi minimum, hot water preferred, with a roof safe detergent. Rinse until runoff is clear.
2. Dry time: 24 to 48 hours depending on humidity. Moisture meter must read below 5% before primer.
3. Seam reinforcement: all field seams, penetrations, and flashings receive polyester fabric embedded in base coat at 1.5 gallons per square.
4. Repairs: blisters cut and patched, fasteners reset, drains reflashed. Budget 5 to 15% of total job hours here.
5. Primer: applied at the rate specified for your membrane type, typically 0.5 to 1.0 gallon per 100 sq ft.

Membrane-Specific Prep Notes

• EPDM: requires a dedicated EPDM primer or wash coat to break the surface oils. Skipping this step causes delamination within 6 to 12 months.
• TPO and PVC: oxidized surface layer must be removed by abrasion or chemical etch. Test a 4 ft by 4 ft area for adhesion before scaling up.
• Modified bitumen: granule loss above 30% needs a granule filling base coat at 2.0 gallons per 100 sq ft before standard application.
• Metal: rust spots wire brushed to bare metal, treated with rust converter, and primed with a corrosion inhibiting primer. Fastener heads receive a butyl cap or seam tape.

Step 8: Post-Application Quality Control

1. 72 hour walk: inspect for pinholes, fisheyes, holidays, and uncured zones. Touch up with brush applied material.
2. Flood test: on low slope sections with internal drains, plug drains and flood to 2 inches for 24 hours where structurally permitted.
3. Photo log: overhead and detail shots of every penetration, seam, and transition delivered to the owner as a closeout package.
4. Maintenance plan: debris removal twice per year, drain clearing each spring and fall, and a written log kept on site.
5. Owner handoff: Wholesale District Commercial Roofing provides system data sheets, warranty registration, and a recoat reminder tied to year 8 or year 10 depending on chemistry.

If you want a project specific scope and number for your building in Wholesale District, contact Wholesale District Commercial Roofing for a site visit. Severity is assessed over the phone, inspections are scheduled fast, and active leaks are prioritized for tarping and dry in before the coating scope is finalized.

Step 7: Warranty and Recoat Schedule

1. Manufacturer material warranties run 10, 15, or 20 years tied to mil thickness applied.
2. Annual inspection required to maintain warranty validity.
3. Recoat at 50 to 60% of original system age extends life by another full warranty cycle.
4. Document every recoat with dry mil verification and photos.

Step 3: Coating System Selection

Chemistry drives both cost and performance. The four common systems in Wholesale District:

• Silicone: best for ponding water. 25 to 30 dry mils. Lifespan 15 to 20 years. Does not chalk in UV.
• Acrylic: lowest cost, best reflectivity. 20 to 25 dry mils. Lifespan 10 to 15 years. Avoid on ponding roofs.
• Polyurethane: highest tensile and abrasion resistance. 20 dry mils. Lifespan 15 to 20 years. Used on high traffic roofs.
• SPF (spray polyurethane foam) plus topcoat: adds R-value. 1.5 inches foam plus 20 mils silicone. Lifespan 20 years with recoat.

For a head to head breakdown, see our comparison of silicone vs acrylic roof coating.

Step 5: Cost Breakdown by System

Line Items That Move the Number

• Repair scope: wet insulation cut outs run $4.50 to $8.00 per sq ft of replacement area.
• Primer requirement: EPDM and aged TPO add $0.20 to $0.45 per sq ft.
• Access: crane or boom lift for material staging adds $1,500 to $4,500 per mobilization.
• Roof complexity: heavy penetration density (HVAC, skylights, vents) can add 15 to 25% labor.
• Tax credit eligibility: reflective systems meeting CRRC standards may qualify for Section 179D deductions on commercial properties.

Step 6: Decision Criteria, Coat or Replace

1. Wet insulation below 25% of roof area: coating is viable after cut outs.
2. Wet insulation above 25%: recommend tear off. Review our coat vs replace decision guide.
3. Membrane age under 20 years and seams intact: coat.
4. Active leaks at multiple penetrations: repair first, then coat, or move to replacement.
5. Deck rust or rot: coating will not save it. Replace.

Step 4: Application Specifications

1. Base coat: applied at 1.0 to 1.5 gallons per 100 sq ft. Wet mil gauge readings every 500 sq ft.
2. Cure window: 8 to 24 hours before top coat depending on chemistry and temperature.
3. Top coat: applied perpendicular to base coat direction for full coverage. Same gallon rate.
4. Final dry mil verification: destructive sample pulled, measured with micrometer at 5 locations per 10,000 sq ft. Must hit spec or a third coat goes on.
5. Weather hold: no application below 50°F, above 90°F, or with rain forecast inside 24 hours.

Equipment and Crew Sizing

1. Airless sprayer: minimum 1.5 gpm output, 3,300 psi rating, with 0.035 to 0.045 reversible tips for silicone and polyurethane.
2. Roller backup: 3/4 inch nap covers for cut in around curbs, drains, and parapet walls.
3. Mil gauges: wet film gauge in every applicator's pocket, dry film micrometer at the foreman's station.
4. Crew ratio: one sprayer, two back rollers, one mixer and supply runner for every 8,000 to 10,000 sq ft per day.
5. Safety: fall protection anchored per OSHA 1926.502, respirators for solvent based systems, and edge warning lines 6 ft from the roof perimeter.