Attic Rain
What is Attic Rain?
During periods of extended cold weather, moisture from the living space or outside sources carried by air movement can accumulate as frost on your attic’s roof sheathing or roof trusses’ underside. You may see ice inside your attic, in or on the roof vents and on or around the soffits. The degree of frost accumulation is related to the relative humidity of the house air, air movement rate into the attic and the length of the cold spell. When the temperature rises above freezing, or the temperature rises and combined with an intensely sunny day, the frost or ice begins to melt faster than the attic’s ventilation system can exhaust the accumulated moisture — this is called attic rain.
Whether or not this results in water leakage into the living space varies with circumstances. Attics are designed to manage small amounts of moisture accumulation. Typically, when the frost or ice changes to liquid water and then to water vapour, it is absorbed into the air and is exhausted harmlessly by attic ventilation to the outside. It may be absorbed by the insulation or the framing and released slowly. It may pool on the polyethylene at the ceiling and evaporate harmlessly.
If factors are present which lead to large amounts of frost or ice in the attic, it can result in leaking into and damaging the home’s interior.
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What does attic rain look like?
The water sometimes leaves a brown stain in the ceiling from the chemicals picked up in the attic's building materials. You may initially think it is a leaky roof, but attic rain builds up due to increased moisture from various sources. The average household puts 50 litres of moisture into the home weekly.
Is attic rain normal?
It is most common in newer homes as they are built to be more air-tight and energy efficient. The side effect of these advancements is reduced air flow and trapping of moisture within the home and/or attic.
Does attic rain cause mould?
In severe cases of attic rain which result in moisture leaking into the home’s interior, mold may be an issue to be concerned with. The conditions which can cause attic rain, are the same conditions required to allow mould growth.
How long does it take for mould to grow in wet attic?
Mould growths, or colonies, can start to grow on a damp surface within 24 to 48 hours. They reproduce by spores - tiny, lightweight “seeds”- that travel through the air. Molds digest organic material, eventually destroying the material they grow on, and then spread to destroy adjacent organic material.
We can help resolve the issue
Many contractors will offer expensive solutions that may only provide a band aid remedy, but not resolve the problem. Shaw Roof Consulting can provide a nonbiased inspection of the attic and roof system to discover the cause and sources of the problem. We can then design a specific strategy to make the required corrective actions. These specifications could be followed, and work performed by an independent contractor of your choosing. We are not here to sell materials and labour, we are here to find the issue and develop an effective corrective plan of action.
Attic rain can cause costly damage your home or commercial building’s interior and structure. Contact us today for a free quote and the peace of mind that comes with a professional resolution to your attic rain problem.