Residential Roofing Materials Guide for Homeowners

Modern roofing industry offers an abundant variety of roofing materials that homeowners can pick for their new roof, or a re-roofing project. Roofing materials differ in visual appearance, cost, durability, maintenance requirements and ease of installation. Anther variable – the roof slope limits the choice of materials suitable for a particular roof.

Gentle and Steep Slopes:

The more level the pitch of the roof, the slower the runoff of water; and a slow runoff calls for an especially waterproof covering. A flat roof surface can be covered with flat roofing membranes such as TPO, EPDM rubber, modified bitumen roofing, built up roof, or a cool flat roofing membrane by IB Roofs. Because of the special skills and tools involved, these materials are best installed by professional roofing contractors; however, they can sometimes be repaired fairly easily. A gentle roof slope can in theory be covered with roll roofing; however despite its inexpensive cost, rolled roofing will only last 5-7 years. Therefore, if you want to avoid having to replace your roof in five years, it makes sense to invest into more durable roofing system such as that offered by IB roofs.

If the roof rises more than 3 inches per foot, then it is considered to be steep, and is suited for a wider range of roofing materials such as asphalt shingles, slate, tile, woof shingles and shakes, and metal roofing systems.

Estimating and Ordering:

Most roofing materials are sold in units called squares, each capable of covering 100 square feet of roofing surface. (The only exception is rolled roofing, and flat roofing membranes that come in rolls of varying lengths, widths and weights). In order to estimate the amount of material needed, determine the area of the roof surface, add 10 percent to allow for double layers of covering along ridges, eaves, and hips, and round the total up to the next highest square. (the next 100 square feet)

Roofing Materials:

Asphalt Shingle – Inexpensive – lasts – 15 -20 years -Minimum Slope 4 in 12. Asphalt shingle roofing is easy to install. It is available in wide variety of weights, styles, and colors; requires little maintenance and is easy to repair. Darker asphalt shingle may not last as long as lighter colored shingles. Goes into landfill at the end of its service life.

Roll roofing - Inexpensive – lasts – 5 – 7 years -Minimum Slope 1 in 12. Rolled roofing is easy to install and repair. Limitations: Poor fire resistance for some types, gets hot in the summer and transfers a lot of thermal solar heat inside the building, requires frequent replacements.

Built-up or Modified Bitumen – Moderate in price – lasts 10-20 years – minimum slope 1/4 in 12. Modified Bitumen is more waterproof than rolled roofing, but it has poor fire resistance for some types; must be installed professionally; leaks are difficult to locate.

EPDM Rubber – Moderate in price – lasts 15-20 years – minimum slope 1/4 in 12. Must be installed professionally. Leaks usually occur in the seams; can be easily repaired.

IB Roof (Modern PVC membrane) – Lasts 30-50 years – No minimum Slope – can withstand ponding water and ice, can further be outfitted with solar roofing panels. Considered to be a cool roof and accredited by green building council, IB flat roofing membrane reflects much of solar radiant heat, which helps keep building cooler and saves money on energy costs over the summer months. Can be properly recycled at the end of its service life.

Wood Shingles and Shakes – Moderate to expensive – lasts 15-30 years – minimum slope 3 in 12 for shingles; 4 in 12 for shakes. Offers attractive rustic appearance and acts as natural insulator. Limitations: Highly flammable unless specially treated; shingles must be laid over open planks or spaced battens.

Slate – Expensive -lasts 50-100 years – minimum slope 4 in 12. Offers attractive traditional appearance; fire resistant. Limitations: Heavy; brittle; requires sturdy roof support; tricky installation that requires special tools; needs regular replacement of damaged pieces; difficult to repair.

Tile – Moderate (concrete) to expensive (clay) – lasts 50-100 years – minimum slope 4-12. Offers attractive and unique appearance; fire resistant. Heavy; brittle;; requires sturdy roof support; time consuming installation; availability of replacement pieces unreliable; difficult to repair.

Metal Roofing – moderate on higher side for galvanized steel and aluminum shingles; expensive for copper lasts 30 – 100 years depending on the system; fire resistant; Offers beautiful modern appearance and a great variety of styles, and finishes. Metal shingle roofing features 4 way interlocking design, which provides reliable wind uplift protection, as each shingle is interlocked with metal shingles next to it. Roof you see below is made with G-90 steel coated with Kynar 500 cool roof rated solar reflective coating. This roof was installed in Rhode Island.

Below you can see standing seam roof, made from aluminum sheet metal roofing panels. This this roof was installed near Boston, Massachusetts. You can also see that standing seam roof has a rail snow guard system, to stop the snow from sliding down the roof. Standing seam roof is coated with special coating that sheds snow and ice, which is especially useful in northern Massachusetts, and New Hampshire where there is significant accumulation of snow. Standing seam roof can last a lift time of the building and help prevent ice dams on your roof.

While standing seam is a premium roof that comes with a price tag, there is a less expensive alternative that has been in use for many years on agricultural and industrial buildings, barns and farm houses. Corrugated metal roofing material is usually made out of thin gauge steel in comes in U shaped form. Although, it was primarily an agricultural type of roofing material, modern day corrugated steel metal roofing can be used to roof over a residential house. For instance, a galvalume steel or aluminum v 5 crimp panel coated with kynar paint finish could be used in residential roofing.

color coated corrugated steel roofing panel

Comparing Roofing Materials

In this post, “Cost” refers to the relative cost of roofing materials alone, does not include the cost of labor. In most cases, the cost of professional installation is higher for roofing materials like slate, tile, wood shingles, cedar shakes, and metal roofing than it is for asphalt shingles, or rolled roofing.

The minimum roof slope is the roofing pitch at which a specific material begins to provide adequate protection against water. All the materials listed can be applied to roofing surfaces steeper than the minimum, but as slopes increase such considerations as appearance durability become more important.

“Durability” provides a rough measure of the length of time a roof will last with proper maintenance in temperate climate.

Resources:

Guide to Re-roofing a house – Homeowners are you ready for a new roof? Here is what you need to know.

Green Roofing – Covers sustainable roofing materials and green roofs.

Metal Roofing Materials Covers modern metal roofing systems and explains metal roofing material properties and options.

Roofing Material Guide Compare and contrast asphalt shingle roofing and metal roofing materials.