Ice Dams On Roof Without Attic

Ask this old house general contractor tom silva explains the best ways to keep your roof and gutters free from those dreaded ice dams.

Ice dams on roof without attic.

If replacing your home s roof have a self sealing membrane installed under the shingles to help prevent water damage from ice dams. An ice dam can damage both your roof and the inside of your home. On metal roofs install snow guards above entrances. Severe ice dams can weigh many hundreds of pounds compromising the structure of the roof eaves.

Ice dams and icicles form when the snow melts runs down your roof and refreezes near the edge. First heat collects in the attic and warms the roof except at the eaves. This scenario is often the result of a warm attic. They occur in climates with cold winter temperatures and regular snowfall.

Here s a breakdown of the conditions that lead to the formation of ice dams. Nonuniform roof surface temperatures lead to ice dams. For ice dams to form there must be snow on the roof and at the same time higher portions of the roof s outside surface must be above 32 degrees f freezing while lower surfaces are below 32f. Meltwater from the warm roof backs up behind it flows under the shingles and into the house.

Add insulation to your attic to help prevent your home s warm air from escaping into unheated attic spaces. An ice dam is a mass of ice that gathers along the lower edge of rooflines. Keeping your roof and attic cold will prevent ice dams because the snow on the roof eventually dissipates without producing a large amount of meltwater. Ice dams are a common sight in northern new england winters and home partners has dealt with quite a few.

Never heat your roof. Without a properly insulated attics however homeowners could find themselves with an ice. Life of an ice dam. Life of an ice dam.

If heat doesn t build up in your attic you probably won t have any ice dams. Finally ice accumulates along the eaves forming a dam. An ice dam is a hump of ice that forms at the edge of a roof under certain wintertime conditions. The underside of the roof deck should not exceed 30 degrees f.

One way to help prevent heat build up and therefore ice dams is to have a well insulated well ventilated attic. The cold season brings snow packed roofs across the country and with snow melt can come damaging ice dams. This only occurs when part of your roof warms to above 32 degrees f warm enough to melt the snow while the roof edge remains below freezing. See below for a shopp.

More critically ice dams can cause meltwater to back up under the shingles where it can flow down and ruin ceiling and wall surfaces.