Does Attic Insulation Affect Shingle Blistering

When attic areas are poorly ventilated excessive heat can cause blisters to form especially on newer roofs.

Does attic insulation affect shingle blistering.

Well the answer to that is yes and no depending on what shingle you have on your roof you may or may not have warranty on your shingles. Does spray foam attic insulation void your shingle warranty from your manufacturer. Second air temperature and wind movement over and under the roof affect the temperature. Roof slope pitch or angle has the least influence on roof deck temperatures.

This is not significant enough to cause any damage to shingles. If your home has an attic or overhead crawl space heat rising up from below can cause blisters and cracks in asphalt roofing shingles. The company has said that rash blistering will not affect the intended performance or life of the shingles and that the shingle warranty will not be affected. The roof absorbs radiant heat from the sun but air flow either wind or attic ventilation has a cooling effect on the roof and helps bring down the overall temperature.

A discrepancy between attic and roof temperatures caused by lack of insulation on the attic floor creates the conditions that yield blisters. Moisture that gets underneath shingles also has the tendency to create blisters on your roof. Roofs with radiant barrier have the potential to lower the temp at night because the radiant barrier prevented the heat loss that would typically occur from the traditional mass insulation on the attic floor rising to heat the roof. Attic ventilation has less effect on shingle temperature than shingle color or orientation.

An overheated attic combined with moisture can cause a number of problems including damage to roof decking and roofing shingles which can become distorted and deteriorate prematurely. See martin s comment below as well as the paper i wrote the article about attic ventilation does help mitigate ice dams in cold climates but doesn t help much in hot climates. Heat that s absorbed in the attic can also radiate into the living space causing air conditioners fans refrigerators and other appliances to work harder. See attic condensation cause cure and roof ice dam leaks.

Attic ventilation reduces the average temperature of a roof deck shingle by only 0 5 degrees celsius 0 9 degrees fahrenheit. Spray foam insulation effect on a shingle roof.