Does The Weight Of Your Roof Matter?

person carrying a large box

When you begin researching different roofing materials, you will discover that roofs can be very heavy or they can be very low weight. The difference can be like parking three fully loaded dump trucks on top of your home, or half of a Mini Cooper.

Depending upon the type of material you choose, the roof on a 2500 square foot home may be as little as 1750 pounds or as much as 50,000 pounds. It seems hard to believe, but it’s true!

So, does it make any difference what your roof weighs? Actually, yes it does.  Let’s take a look at some of the factors that need to be considered.

First of all, some roofs are heavy largely because it is weight and gravity that holds them securely to the roof. Many roofing materials have no interlocking features and few fasteners securing them to your home’s structure.

Those materials need to be heavy or else they will not hold securely in high winds! Other materials, though, which feature interlocks between the panels or shingles, and which are secured to the roof deck, can be very wind resistant while also being very low weight.

Next, as a home ages, its structural materials often weaken. This can be a factor with most engineered woods and even with dimensional lumber. It is often a huge factor with fire-treated woods. Lower strength means that the home is more likely to shift or move under the heavy weight of roofing materials.

Taking some of the weight off of the home can help preserve the home’s life as well as its structural integrity in the event of a catastrophic wind storm.

A lower weight roof can also protect the home from damage due to earthquakes and other seismic activity. After the catastrophic earthquake in Kobe, Japan in 1995, many folks began rebuilding with low weight roof materials rather than their traditional heavy tile roofs.

A low weight roof also lessens the risk of a roof collapse if there is a fire inside of the home which reaches the attic. In fact, with many heavy roofs, fire fighters will not go inside the home to fight the fire if it has avery heavy roof on top.

Here is a list of sample roofing material weights, per 100 square feet:

Aluminum Shingles 45 pounds

Aluminum Standing Seam 70 pounds

Steel Shingles 80 pounds

Steel Standing Seam 120 – 150 pounds

Stone-Coated Steel Shingles 125 – 150 pounds

Asphalt / Fiberglass Shingles 275 – 325 pounds

Dimensional Shingles 350 – 425 pounds

Composite Shingles 350 – 450 pounds

Wood Shingles 300 – 400 pounds

Wood Shakes 450 – 600 pounds

Concrete Tile 450 – 700 pounds

Slate 900 – 1200 pounds

Clay Tile 900 – 1500 pounds

At McCarthy Metal Roofing, we believe that a homeowner’s best option is a low weight roof which features secure fastening to the roof deck and interlocking panels with the strength of metal. Homeowners get the best of all worlds with these products!

Please contact us today if you’d like to discuss a metal roof for your home!