As a building owner or property manager in Burnaby, you are likely well aware that our local environment is a beautiful but demanding one. Our structures face a unique set of meteorological challenges. Therefore, we put together this guide to dive deep into the specific roofing issues we often see in the Burnaby area and explain why proactive management is the most cost-effective strategy for your commercial property.
Here are some common issues we notice with commercial roofs in Burnaby:
Biological Growth & Moss
Burnaby experiences roughly 170+ rainy days per year. This persistent moisture, combined with our mild coastal temperatures, creates a petri dish effect for moss, algae, and lichen to grow.
What it is: Most commonly seen as green, carpet-like mounds on shaded or north-facing sections of a roof.
Why it happens here: Proximity to high-density treed areas (like Central Park or Deer Lake) increases organic debris and spore counts on rooftops.
The Problem: Moss isn’t just an aesthetic issue. It acts like a sponge, holding water against the roofing membrane or shingles. In commercial flat roofs, this trapped moisture can cause the membrane to rot or delaminate. On sloped roofs, moss can actually lift shingles. If this happens, it allows wind-driven rain to reach the sensitive underlayment.
Ponding Water
Burnaby’s rainfall can be intense, especially during the atmospheric rivers we often see in late fall and winter. Many commercial buildings in our area utilize low-slope or flat roofing systems.
The Issue: Ponding occurs when water remains on a roof for more than 48 hours after a rain event.
Where we see it: Usually around HVAC units, near drains that have become clogged with debris, or in areas where the building has naturally settled over time, creating low spots.
The Risk: Standing water is incredibly heavy (roughly 62 lbs per cubic foot). This weight causes further sagging and creates a vicious cycle. More importantly, constant submersion accelerates the breakdown of UV-protective coatings and roof seams, leading to catastrophic leaks.
Wind-Driven Rain and Flashing Failures
Burnaby often faces high-velocity winds that don’t just push rain downwards, they push it sideways.
The Vulnerability: Most roof leaks don’t happen in the middle of a membrane; they happen at the flashing, the metal transitions around chimneys, vents, skylights, and parapet walls.
How this happens: High winds create pressure differentials. If a piece of flashing is even slightly loose or if the sealant has cracked due to UV exposure, wind-driven rain can be forced up and under the protective layers.
The Result: This often leads to phantom leaks that only appear during specific storm directions, making them difficult to track.
Clogged Drainage Systems
In a city as green as Burnaby, fall is a high-risk season. Leaves, pine needles, and twigs from nearby trees rapidly accumulate in commercial internal drains and scuppers.
Who is at risk: Buildings located near residential neighbourhoods or parks.
The Consequence: When a primary drain is blocked, the roof effectively becomes a swimming pool. If the overflow drains aren’t fully cleared, the water level can rise above the flashing heights of HVAC curbs, causing gallons of water to pour directly into the building’s interior.
How Professional Assessments Reduce Long-Term Costs
Many property managers view roofing as a reactive expense, rather than a proactive one. Usually, clients call us when something happens that you only pay for when water is dripping onto a tenant’s desk. However, data shows that a proactive maintenance plan can extend a roof’s lifespan from an average of 13 years to 21 years. That’s huge savings.
Canuck Roofing Assessments:
- Core Sampling & Infrared Scanning: We don’t just look at the surface. We use technology to detect moisture trapped under the membrane before it rots the structural decking.
- Seam Integrity Testing: We physically inspect every heat-welded or glued seam. Catching a $500 seam failure today prevents a $50,000 interior mold remediation tomorrow.
- Debris Clearance & Biocide Treatment: We schedule a roof cleaning to remove debris and algae. We apply eco-friendly treatments to prevent moss from returning.
- Budget Forecasting: A professional report provides 1-, 5-, and 10-year outlooks, helping you transition from emergency repairs to planned capital investments.
In Burnaby, your roof is your building’s first line of defense against our rainy climate. By understanding the specific local threats from moss growth to wind-driven rain and partnering with professionals for regular assessments, you aren’t just spending money on a roof; you’re protecting the assets and people beneath it.
Is your building ready for the next rainy season? Start this summer and get ahead to prepare for fall and winter. Contact Canuck Roofing today for a roof assessment.