Getting Your Roof Ready for a Colorado Winter

Why Front Range Winters Are Hard on Roofs

Snow on a Denver metro roof rarely sits still. A sunny afternoon melts it, the water runs into every seam and gap, and it freezes again overnight. Water expands when it freezes, so a small opening at a flashing or a cracked pipe boot gets a little bigger each cycle. By spring, a gap you could not see in October can be a leak.

Wind is the other half. Strong downslope winds come off the foothills in winter, and they lift shingles whose seal strips have weakened with age. A shingle that has been lifted once no longer seals, and the next storm takes it.

A Fall Checklist

• Flashing at chimneys, walls and skylights: look for gaps, lifted edges or rust. This is where most winter leaks start.
• Pipe boots around plumbing vents: the rubber collar cracks in the sun after some years, and it is a cheap part that causes expensive water damage.
• Missing, lifted or creased shingles, especially along ridges, edges and the side of the roof facing the prevailing wind.
• Gutters and downspouts: clear the leaves so melt water has somewhere to go. A packed gutter holds water right at the roof edge, where it freezes.
• Branches over the roof: trim anything that rubs the shingles or could drop under a load of wet snow.
• The attic: on a cold day, look for frost on the underside of the roof deck, damp insulation or stains. All three point to warm, moist air getting where it should not.

Ice Dams, and Why They Start in the Attic

An ice dam is a ridge of ice along the roof edge that holds back melt water behind it. The water pools, backs up under the shingles, and comes through the ceiling or down the inside of an exterior wall.

The cause is usually heat, not the weather. Warm air from the house leaks into the attic, warms the roof deck, and melts the snow from underneath. The water runs down to the cold eave and freezes there. Better attic insulation, sealing the gaps where house air leaks into the attic, and proper roof ventilation keep the deck cold and stop the cycle at its source.

On a new roof, ice and water shield at the eaves is the backstop: a waterproof membrane under the shingles where ice dams form. We install it on every roof replacement. On an existing roof, if you have had ice dams before, have the attic and ventilation looked at before winter rather than chipping ice in January.

What Can Wait Until Spring, and What Cannot

Worn but intact shingles on an otherwise sound roof can usually wait for spring. Winter is a poor time for a full replacement anyway: shingles need warmth to seal properly, and short cold days leave little working time.

What should not wait is anything that already lets water in: a lifted flashing, a cracked pipe boot, missing shingles, or stains that have appeared since last winter. Those are small repairs in October and a ceiling, insulation and drywall job in March.

Stay Off an Icy Roof

Please do not climb onto the roof to clear snow or chip ice. It is the most dangerous job around a house in winter, and chipping at ice breaks shingles. If you see water coming in, call; we would much rather come out than have you on a ladder.

If you are not sure what shape your roof is in, a free inspection before the first real storm is the simplest way to find out. We will photograph what we find and tell you what needs doing now, what can wait, and what is fine.

From Our Own Jobs

See More of Our Completed Roofs