Cleaning and Protecting RV Roofs in Alberta's Strong Sun

Calgary and much of southern Alberta sit at higher elevation under clear skies much of the year, so your roof gets more ultraviolet exposure than many owners expect. UV breaks roofing materials down slowly. Rubber membranes start to chalk and thin, and fibreglass gelcoat loses its shine and turns dull and powdery.

Our climate adds other stresses. Warm days followed by cold nights make roofing materials expand and contract, and that movement works at the sealant joints. Dust from gravel roads and fields settles on the roof and holds moisture against it. Tree sap and bird droppings can stain the surface and wear it down if you leave them sitting.

Most rubber roofs are EPDM or TPO membranes. Before you start, check your owner's manual or the roof manufacturer's guidance, because a cleaner that is fine on one material can damage another. When in doubt, start with plain water and a mild, non-abrasive soap.

Use a soft or medium bristle brush and work in small sections, rinsing as you go. Avoid petroleum-based solvents, harsh degreasers, citrus-based cleaners and anything abrasive unless the product says it is safe for your roof type. These can soften, swell or dry out the membrane. Rinse thoroughly, and try to keep the runoff from leaving streaks down the sidewalls.

Some light chalking on an EPDM roof is normal as it ages. The things to watch for are heavy buildup that washes down the sides in streaks, and a membrane that has worn thin enough to show the backing underneath.

Fibreglass roofs are more rigid and generally hold up well, but the gelcoat surface still oxidizes in strong sun. Wash with a mild soap made for RVs or boats, rinse well and let the surface dry completely.

Once the roof is clean, a wax or UV protectant made for fibreglass helps slow oxidation and makes the next wash easier. If the surface is already chalky, you may need a fibreglass cleaner or a light oxidation remover first. Go gently, because aggressive compounding can wear through thin gelcoat.

Look closely for hairline cracks, especially around vents, the air conditioner and anywhere the roof flexes. Even small cracks can let water reach the structure underneath.

Only walk on the roof if your manufacturer says it is built to carry weight, and never when it is wet, frosty or windy. A sturdy ladder, soft-soled shoes and a helper on the ground make the job much safer. If your roof is not walkable, clean what you can reach from a ladder and leave the rest.

While you are up there, check the sealant around vents, skylights, antennas, the air conditioner and the roof edges. Cracked, shrunken or lifting sealant is an easy fix now and a costly one after water gets in. Wash and inspect the roof a few times each season, and again after any hailstorm or a long stretch parked under trees.

Bring your RV to Horton RV Services in Calgary if you find soft or spongy spots, tears or bubbles in the membrane, cracks in fibreglass, lifted edges or water stains on the ceiling inside. These usually mean moisture has already reached the roof deck, and it is better to have it checked before the damage spreads.