Greenwich Roofing: Article About Underlay
During the construction of a roofing system, several layers of materials come together to create a waterproof, moisture proof and weather proof barrier against the elements. Between the exterior tiles or shingles and the wooden decking is a layer called the underlay. This material, sometimes referred to as roofing felt, helps to extend the lifespan of the roof while protecting the substructure below. Although the underlay is hidden, it plays an essential role in the durability and lifespan of the rooftop. A local Greenwich roofing expert can help any homeowner sort through the different types and features of underlay materials.
One of the most important traits of the underlay is its ability to stop or resist moisture. A moisture resisting rating of less than 1 means that the material resists the penetration of water. A rating of above 1 suggests that the material can stop rain and humidity from passing through it. Homes located in areas with high humidity and frequent rains or snows would benefit from a material rated greater than 1.
Homeowners should also consider the fire resistance rating of different underlays. This is a measurement of how well the material is able to suppress the spread of fire. Concrete mesh has the highest level of protection against fires but is rarely used in houses due to its bulk and cost.
The roofing experts at Sound Renovation of Greenwich CT can assist you with any questions regarding asphalt roofing or metal roofing.
Gypsum, which is used in most residential roofing systems, has a fire rating of A. This means that it offers a strong resistance to fire. Asphalt based underlays have the lowest fire ratings but tend to have good waterproofing abilities.
The climatic attributes are also an important factor in choosing an underlay. In the Midwest and Northeast, most homes should use a hot, cold wet rated underlay. This material can withstand the frequent and extreme temperature change and rapid rises and drops in humidity levels. If the installation of the roofing system takes longer than expected, this kind of underlay can protect the sheathing for an extended period of time.
Finally, homeowners will need to consider the type of exterior roofing material they plan to use. Some synthetic underlays are rated best for use with specific materials like concrete tile or cedar shakes and are incompatible with anything else. These sorts of details will be explained by the manufacturer on the product's packaging. Using an underlay that is not recommended for the shingles or tiles could result in excessive ultraviolet light damage, blistering shingles, telegraphing, curling and even premature failure of the roof.