There are many different types of roofing in Washington DC, from flat roofs to pitched roofs, but also many different materials. Here we are going to go over many of the most common roofing materials you’ll come across in residential applications in our nation’s capital. It’s useful to know what kind of roof you have and what materials it’s made of so that you can find the right roofer to repair or replace it when the time comes.
Whatever kind of roof you have, we can help you repair or replace it.
The majority of roofs in Washington DC fall into this category. Almost all row homes or row houses have a flat roof (also called a low slope roof). While the name implies something without a slope, it’s something of a misnomer because all roofs have some pitch for drainage, and flat roofs in DC actually have more pitch than the prominent designs in many other major cities. The defining characteristics of a flat roof is not that it’s completely flat, but that it has too low of a slope for roofing materials like shingles and slates. Those types of materials require a much steeper pitch to keep the rain water from getting under each previous layer while running down to the gutter, while on a flat roof the seams are sealed and don’t rely on gravity to move the water away.
- Modified Bitumen (rubber roofs)
Modified bitumen roofs are the most common roof materials in DC. With an average lifespan of around 20-25 years if properly maintained (Roof Coatings and Sealants). They originally came only in a smooth black material but now come in white granulated (much like an asphalt shingle). This is the standard roof we install and trades a lower life expectancy than some other materials for a lower upfront cost, while still being a high quality roof. For a new modified bitumen roof Click here
TPO roofs are a white polymer roof that is gaining ground on the traditional mod bit roofs. It’s benefits are a longer lifespan (25-30 years) and an all white membrane that doesn’t require coatings to remain white and give you the uv reflection benefits of a white roof. The downside is the higher upfront costs and a shorter track record than mod bit in residential applications.
Gravel roofs, or slag, rock, pea gravel, tar and gravel, are an older roof application and really haven’t been installed in dc for a while. The ones still around are usually more than 20 years old and should most likely be replaced. They were a cheaper roof to install and were a decent roof for the first decade after their install but often had problems after that and were very hard to almost impossible to stop a leak in permanently.
These roofs are also called gabled roofs, A-frame roofs, peaked roofs, and several other names. Essentially, if you can see the roof surface from the ground you have a pitched roof. There are many different materials that a pitched roof can be made of, and they all have varying life spans and repair costs.
One common type of roofing material in the District of Columbia is slate. Slate roofs are made of a natural quarried stone and have a very long life. It’s not unheard of to see 75 year old slate roofs still intact. The downside of slate is it’s weight and it’s very high upfront cost. In fact it’s one of the most expensive roofs you can put on your home.
Also available is a synthetic slate for the aesthetics of slate but with less weight and less upfront costs. They’re typically made of a polymer and have a much shorter lifespan than natural slate, but can cost considerably less to install. Here at CJ Roofing we repair both natural and artificial slate roofs. Click here for more on slate Roof Repairs
- Asphalt shingles
Another very common pitched roof in DC is an asphalt shingle roof. If your roof appears to have a colored granular surface it’s most likely an asphalt shingle roof. It’s also the majority of roofs on homes built after the 1960s. Shingles have a lifespan ranging from 20-40 years in real world conditions. They’re made of layers of asphalt and fiberglass with a mineral surface that gives them their color. While their life is half of the possible lifespan of slates, their cost is less than half too and many homeowners decide this trade off is worth it.
Shingle roofs can be easily repaired if damaged by wind or sometimes by falling branches or animal damage.
Metal roofs come in both pitched and flat varieties in DC. The pitched metal roofs can be made of aluminum, steel or copper. Aluminum and steel being the most common. Some newer metal roofs have a built in alloy to resist rust and corrosion, but some need to be maintained with a rustproofing to keep the roof in tip top shape.