All Around Roofing: Trusted Roofing Denver
Attic ventilation and insulation are an essential aspect of a roof. When these components are in good condition and functioning well, a roof can achieve and even surpass its service life. When ventilation and insulation are inadequate, the resulting symptoms can shorten the roof’s lifespan.
Homeowners should be aware of two important facts about attic ventilation. Firstly, the science of ventilation has evolved greatly in recent years. A house that’s older than a decade may have an outdated ventilation system and is likely due for an inspection by a Denver roofing professional. Secondly, attics are not meant to be cool during the summer or warm the during winter. Effective ventilation achieves a balance with outside weather conditions so that the roof topside and underside are at similar temperatures.
Consider what can happen to a roof in winter after snow or ice accumulates and the attic is warmed with the rest of the house. The top of the snow remains frozen due ambient temperatures, but the underside begins to melt due to the warmth of the roof. This results in pooling water that becomes trapped between the snow and the roof.
This creates pressure, and that pressure forces that water out through the path of least resistance, which is often the thin gap between shingles.
On the other hand, if an attic is too cool during the summer, then that can result in condensation. Even a small amount of condensation can result in mildew, which often creates a smell that’s distributed throughout the home by the central air conditioning system. If this additional moisture persists, it will permeate throughout the roof structure, leading to more mildew and even rot.
A potentially even bigger problem than an attic being too cool during summer is the potential for overheating. Although asphalt shingles are designed to withstand high temperatures, the total heat created by external temperatures and direct sunlight coupled with the superheated temperatures in the attic can exceed that limit. In these conditions, the shingles will break down at a faster rate.
In the worst case, shingle blistering occurs. What happens is that the asphalt gets so hot that it begins to bubble. Bubbling and then resetting, which is common during the set in period for asphalt shingles, is all right. However, if the attic is hot enough to cause blistering, then those blisters are prone to opening up, and the liquefied asphalt can run. Popped blisters can expose a shingle’s middle layers, and liquefied asphalt can cause a shingle to lose all of its granules.