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R-Value: Important Information about Roof Insulation

Roofing terminology can be challenging. But not knowing enough about your roofing system can cost you, both in your electrical bills and when it’s time to work with a roofing company. There are even some roofers who will take advantage of your lack of knowledge to upcharge or cut corners with items like insulation!

A term you will hear a lot when discussing your roof’s insulation is R-value, which is a key part of assessing your roofing system. R-value is the measurement of how well insulation materials resist heat through conduction. The higher the R-value, the better the insulation performance will be. Understanding what affects R-value will make you a more informed homeowner when it’s time for a roof repair or replacement.

The Department of Energy recommends Maryland homes have an attic insulation R-value between R38-R60. When you need to increase your attic’s R-value, first understand that the type of insulation, thickness, density, temperature, and moisture accumulation can all affect this value.

Accurately calculating exactly how much insulation your home needs is something a professional roofer should do. Guessing how much insulation you need will only cause problems in the long run. Your roofer should both get on the roof to assess its condition and look in your attic to see if you need additional or new insulation.

If it is time for new insulation, you will need to choose between batts, blown-in, and spray foam insulation. The insulation’s packaging will indicate the R-value that the insulation will provide per square inch. However, this is just the nominal R-value; real-world factors will impact how well the insulation performs. Batts can create a strong barrier but leave gaps in coverage. Foam spray gives you more storage space, but it doesn’t allow for proper ventilation. So, Brothers’ roofing experts recommend blown-in insulation.

Blown-in insulation is best for filling in every crevice of the attic, increasing your attic’s R-value, with more efficient heating and cooling. However, blown-in insulation does settle over time. It will appear less thick after a few years, but the density will increase. That means the R-value does not change proportionally with the thickness to a certain level. But, after about ten years, your insulation will settle to the point that it does affect the insulating properties and will need to be added to or replaced. Additionally, no matter how old your insulation is, if it has gotten wet from a roof leak, it will no longer be effective and will need to be replaced.

But remember, insulation is just one part of your roofing system. Layers like the decking, underlayment, and shingles will impact your home’s energy efficiency too. Additionally, proper ventilation is vital to ensure that your attic keeps a stable temperature. So, even if insulation boasts a high R-value, it could be meaningless if the rest of your roofing system is not correctly calculated and properly installed.

If you are considering a roof replacement, or simply need to add insulation, the roofing experts at Brothers can help. We will inspect your roof inside and out and take exact measurements to give you the best options for your home. Schedule a free, no-pressure consultation today!