Commercial asphalt roofing in Spokane County must handle heavy winter snow loads and rapid spring thaws that push water under seams on flat and low-slope roofs. Older commercial stock along North Washington Street and in the East Sprague corridor often features built-up asphalt systems installed decades ago that now show alligatoring and blistering from decades of freeze-thaw cycles. Proper flashing at HVAC curbs and parapet walls becomes critical because wind-driven snow finds every gap.
Material choices matter on Spokane roofs. Modified bitumen cap sheets with granular surfaces hold up better than standard felt under the area's UV exposure and occasional hail. Edge details at scuppers and internal drains require extra attention since clogged drains from autumn leaves turn minor leaks into ceiling damage inside warehouses and retail spaces. Crews typically torch or cold-apply seams only when daytime temperatures allow proper adhesion.
Code compliance in Spokane requires verification of existing deck condition before overlay work, especially on buildings with original wood or lightweight concrete decks. Removing wet insulation layers prevents trapped moisture that later causes blistering. Walk pads around rooftop units protect the membrane from foot traffic during maintenance visits that occur year-round.
Drainage slope corrections during re-roofing prevent ponding that is common on older flat roofs in the downtown core. Adding tapered insulation or crickets at low spots extends service life without full tear-off when the deck remains sound.
Technician insight
In Spokane the thing that catches most people out with Commercial Asphalt Roofing is how quickly snow melt refreezes inside poorly sealed seams on flat roofs once temperatures swing at night, especially on buildings downtown where heat loss from below keeps the membrane cycling through freeze-thaw more than suburban sites.
Warehouse Roof on East Sprague
Ponding water after a March thaw had entered a 1980s warehouse through failed seams around two HVAC units. Core samples showed saturated insulation over a 2,800 sq ft section. We removed the wet layers, installed tapered insulation to restore slope to the existing drains, and recovered with a new modified bitumen cap sheet. The owner reports no further interior leaks through the following winter.
Commercial Asphalt Roofing Services We Offer
✓Commercial Asphalt Membrane Repair
Targeted patching and seam welding on existing built-up or modified bitumen roofs to stop active leaks before they reach tenant spaces.
✓Flat Roof Asphalt Coating
Application of reflective asphalt-based coatings that restore UV protection and extend the life of aging commercial membranes in Spokane summers.
✓Asphalt Shingle Replacement Commercial
Full or sectional replacement of asphalt shingles on sloped commercial buildings such as retail strips and small office complexes.
✓Commercial Roof Drainage Correction
Installation of additional drains, scuppers and tapered insulation to eliminate ponding common on Spokane flat roofs after heavy snow melt.
✓Rooftop Equipment Flashing Repair
Re-sealing and replacement of flashings around HVAC curbs, skylights and vents that fail first under Spokane wind and snow loads.
✓Asphalt Roof Tear Off and Recover
Complete removal of failed layers followed by new asphalt membrane installation when multiple overlays have reached code limits.
Commercial Asphalt Roofing Cost in Spokane, WA
| Service | Typical Range | What Affects It |
|---|---|---|
| Commercial Roof Inspection | $250–$600 | Size and number of penetrations affect final cost |
| Asphalt Coating Application | $1.80–$3.50 per sq ft | Depends on surface prep and coating thickness |
| Membrane Repair Patch | $400–$900 | Number and accessibility of leak locations |
| Full Asphalt Re-roof | $6–$11 per sq ft | Tear-off layers, deck repairs and slope work drive price |
| Drainage Improvement | $1,200–$3,800 | New drains or tapered insulation packages |
Ranges are typical for Spokane, WA and confirmed with an exact written quote before any work starts.
How it works
- 1
Site Assessment
Walk the roof with infrared moisture scan and core cuts to map wet insulation and deck condition.
- 2
Scope And Material Selection
Match membrane type and slope corrections to the building's use and existing drainage.
- 3
Preparation And Removal
Remove wet materials, repair deck sections and install new base layers as needed.
- 4
Installation And Detailing
Apply new asphalt system with attention to all penetrations, edges and drainage points.
- 5
Final Walk And Handover
Inspect seams, drains and walk pads then provide maintenance guidelines for the owner.
Pricing
Upfront quotes based on roof size, layers present and drainage work required; no hidden change orders after inspection.