Ice Dam & Roof Snow Removal in Chelmsford, MA

Senco works out of 1150 Main St in Tewksbury, about 9 miles from Chelmsford by way of Route 38. We've put roofs and siding on Chelmsford homes, and each winter our crews take ice dams and heavy snow off roofs across the area using steam and roof-safe tools. This page covers what that looks like on a Chelmsford house. For the full picture across our service area, including what you can safely do yourself, see our ice dam & snow removal overview.

Why Chelmsford's 1950s And 60s Houses Ice Up

Chelmsford grew from 8,077 people in 1940 to 31,432 in 1970, and its houses show it. The median Chelmsford home was built in 1967, about one in four went up in the 1960s alone, and another 15% predate 1940. Attics in houses from those years were insulated and vented to the standards of their day, well short of what code asks for now. Warm air from the rooms below works into the attic and heats the roof deck, the snow on top melts, and the water runs down to the overhang, where there's no heated room underneath, and freezes again. A few nights of that builds a ridge of ice at the eave, and the next melt has nowhere to go but under the shingles. Our ice dam cutaway walks through it one layer at a time.

Where The Water Goes

A shingle roof is built to shed water running downhill, so the water pooled behind a dam finds its way backward under the shingle laps, through nail holes and underlayment seams, and into the sheathing and insulation. Inside, it shows up as a brown ring on a ceiling, a damp patch on a wall, or a drip at the top of a window, often a few feet from where the ice sits. If the water's already in, our Chelmsford roof repair page covers how we trace the leak and fix it.

Snow Load On A Chelmsford Roof

The Massachusetts building code sets Chelmsford's ground snow load at 50 psf, the same figure it uses for every town we serve, and a well-framed roof carries an ordinary winter without trouble. The big storms are the test. The January 2015 blizzard left 33.8 inches in Chelmsford by the National Weather Service's count, and wind piles snow like that into valleys and against the wall where a low roof meets a taller one. An ice dam at the eave puts the water and the heaviest snow on the same edge of the roof. If your roof is sagging or creaking under snow, call us. If it was near the end of its life anyway, our Chelmsford roof replacement page covers the next step. Our guide to how much snow a roof can hold covers the warning signs.

How We Take An Ice Dam Off

We use low-pressure steam. It cuts a channel through the dam down to the shingles so the trapped water can drain off the roof, and it leaves every shingle and its granules in place. A hatchet or hammer pulls shingle away with the ice, and rock salt eats at shingles, gutters, and the plantings below. Steam is slower, and on an asphalt shingle roof it's the only method we'll use.

Taking Snow Off The Roof

Where heavy snow is loading the roof or feeding the dam, we clear the eaves, the valleys, and the places it drifts, with tools made for roofs and never a shovel scraped across the shingles. The point is less weight on the framing and less snow left to melt into the next dam, and that doesn't take scraping the roof bare.

If The Ice Damaged The Roof

Sometimes a dam has done enough harm, or the roof is old enough, that patching it doesn't make sense. Chelmsford issues a re-roof with no structural change under its Residential Short building permit, from the Building Department at 50 Billerica Road (978-250-5225), which stays open until 7 PM on Tuesdays. We pull that permit on every Chelmsford roof we replace. Homes in the Chelmsford Center Historic District have one more step, since the Historic District Commission reviews construction changes there. Before any exterior work in the district, we check with the commission and plan around its meeting on the first Monday of the month.

Stopping Next Winter's Dam

Steam stops the leak you have. Keeping it from coming back is warm-weather work, and on a 1950s or 60s Chelmsford house it usually starts in the attic: insulation where it's thin, and ventilation that brings cold air in at the soffits and lets it out at the ridge, so the whole roof deck stays cold and the snow melts evenly or not at all. Massachusetts also requires an ice barrier at every eave, from the roof edge to at least 24 inches inside the exterior wall line, and 36 inches along the slope on roofs pitched 8:12 or steeper. On every Chelmsford roof we replace, that barrier goes down before the first shingle. Gutters matter too, because a gutter packed with leaves holds meltwater right at the eave, and our Chelmsford gutter page covers that side.