What Is A Flat Roof And What Is It Made Of?

The flat roof has been around for centuries. What is a flat roof and what is it made of are two things you should know. Today, the flat roof is contemporary due to its shape.

But what is a flat roof and why it becoming more popular?

What Is A Flat Roof?

Flat roofView in gallery
Image from Guy Ayers

A roof needs a drainage system. Homes in rainy climates require drainage, so flat roofs aren’t popular. Most “flat roofs” have slopes and aren’t flat. 

Most flat roofs are set at ten-degree angles or less. They look flat while and water a place to run. Drainage should be your number one concern when building a flat roof.

Flat Roof Materials

Flat Roof MaterialsView in gallery
EdgeWork Design Build

How are flat roofs made? They are made with the same materials as heavily-inclined roofs. The difference is flat roofs require water resistance. 

BUR – Built-Up Roof

Built-Up Roof is one of the most common flat roofs. It has felt and adhesive layers. It starts with the deck board, followed by insulation. After that, layers of asphalt and felt are changed, with gravel being put on the top layer of the asphalt. 

The top layer reflects the sun, keeping the inside insulated. It also protects the lower layers from weathering. Gravel is easy to replace, so you can pour more on it when needed. 

GRP – Glass Reinforced Polyester 

Also known as fiberglass, GRP roofing is a good choice. The tongue in groove roofing is laminate, which has a special resin for roofing. GRP is easy to install on flat roofs.

GRP lays like tin. You may need to take a training course, but this roofing is easier to lay than BUR, which requires a certified team. 

Bitumen

BUR uses tar, but bitumen is a substitute. Tar smells bad and is messy.  Bitumen uses layers of asphalt with a protective topcoat of sealant or other protective material. 

The best part about bitumen is it comes in peel-and-stick pieces, so it’s easy to apply. You can get peel-and-stick asphalt that works just as well as poured asphalt and is more affordable than other roofing options. 

EPDM – Ethylene Propylene Diene M-Class Rubber

EPDM is a single-ply membrane roofing type made with synthetic materials. Most EPDM is a rubber adhesive that is one of the cheapest ways to cover a flat roof. There are other single-ply membrane options, but this is the cheapest.

EPDM absorbs heat. You’ll need to add a top layer to reflect the heat or else you’ll have a house much warmer than you intended. In the end, it may cost as much as other options this way. 

Vegetation 

Vegetation roofing is one of the oldest roofing types. Clay and thatch roofs became the standard. Vegetation roofs are making a comeback. 

This type of roof has vegetation that grows over a waterproof system. Sod is for home garden use.  You can grow plants on your roof.

Flat Roof Repair

Repairing flat roofs is easier than fixing sloped roofs. Because there are no angles or curves, you can use flat materials to repair a flat roof. It also helps that most flat roofs are made with felt or asphalt.

It’s easy to repair both materials. You can keep extra asphalt to make quick repairs. However, calling a professional is recommended if you had a professional install the roof. 

Flat Roof Shed

Flat roof sheds are popular. They can have a flat roof if you’re not sure you want one. Since sheds are small, around 10 to 16 ft wide, they are easier to roof.

Most flat roof sheds use bitumen over tin or plywood. If you’re buying from a manufacturer, it’s a good idea to add 5-degrees to the pitch to prevent water buildup in sheds. 

Pros And Cons Of A Flat Roof

Pros And Cons Of A Flat RoofView in gallery
Kelly And Stone Architects

Roofing types have pros and cons. Here’s what you need to know about the dangers and benefits of flat roof homes. 

Pros Of Flat Roofs

  • Roof Space – if roof space is important, then a flat roof is your best option. You can use it as an outdoor area, which is perfect when you don’t have your own yard. In some cases, swimming pools are even added to flat roofs. 
  • Easy Repairs – flat roofs are easy to repair. Sloped roofs come with safety concerns when repairing and need special materials to wrap around the curves of the roof’s pitch. 
  • Fewer Materials Needed – flat roofs can require as much as half the materials as pitched roofs This comes with downsides, but it also means that it is much cheaper. 
  • Easier To Heat And Cool – if your roof is well-insulated, flat roofs are easier to keep cool and warm. Especially cool! Air and heat won’t get trapped in the pitch and you can buy smaller HVAC units. 
  • Easy To Clean – flat roofs are easier to clean because you can stand on top of them. For this reason, cleaning them is like cleaning a really dirty floor! You can use a broom or Shopvac. 

Cons Of Flat Roofs

  • No Attic Space – flat roofs don’t have a pitch, you won’t have the storage space that an attic does. This can be overcome by buying an outdoor storage building, but that cost can add up and it’s hard to find room for one. 
  • Hard To Drain – flat roofs offer little to no drainage. This requires a special drainage system or a lightly sloped roof, making true flat roofs nearly non-existent. 
  • Snow And Ice Can Settle – flat roofs allow snow and ice to pack on. This can weigh down on the roof, and in extreme cases, cause it to collapse. This is why flat roofs aren’t recommended in cold climates. 
  • Don’t Last As Long As Sloped – flat roofs don’t last as long as sloped roofs. They need to be replaced and repaired about twice as often as sloped roofs. Since they are cheaper, it’s hard to decide if it’s worth it or not. 

Gorgeous Flat Roof HouseProjects

Here are a few flat roof projects for you to enjoy: 

Cantilevered Flat Roof House By Paulo Martins

Cantilevered Flat Roof House By Paulo MartinsView in gallery

If you’ve never heard of the world “cantilevered,” nows the time to learn it. It means “fixed or supported at only one end,” and refers to structures. This cantilevered flat roof house by Paulo Martins is eclectic and inspiring.

Flat roofs are perfect fit for this home.   

Floating Australian Flat Roof House By FGR Architects 

Floating Australian Flat Roof House By FGR Architects View in gallery

Here we have another gem that appears to be floating. The home is a FGR Architects design in Portsea, Australia. The house is very modern and simple, offering a strong geometric design.

In geometric houses like this, a flat roof can work wonders. Imagine a house like this with a pitched or sloped roof. It doesn’t have the same effect, changing the aesthetics entirely. That’s what a flat roof can do for any home.

The Ursa House By Pearson Design Group

The Ursa House By Pearson Design GroupView in gallery

Not all flat roof homes have to be modern and stark. This design by Pearson Design Groupe and On-Site Management proves that to be true. This house portrays the perfect marriage between modern and rustic.

The home has a modern shape with a flat roof but offers rustic textures. It features rough shiplap and earth tones. 

Raised Argentinian Flat Roof House By Guaresti/Altieri Arquitectura 

Flat roof house in portugal with garageView in gallery

The goal was to build this house on the beach with multiple views. The house sits on stilts that protect it from water and offer a better view.

The homeowners wanted a low-maintenance house with a flat roof. The builders went with a concrete design. Though not as popular due to its high price tag, concrete roofs work well in flat roof homes. 

Brazilian Pool House By Schuchovski Arquitetura

Brazilian Pool House with flat roof By Schuchovski ArquiteturaView in gallery

The Brazilian home sits on a hilltop. The view is part of the property. Each layer of the home has different flat roof designs. 

The house is modern. It has a spiral staircase, huge rooms, and contemporary furniture. There’s a commercial feel to this house which adds to its charm and separates it from others. 

Primitive Portuguese Home By Artspazios 

Flat roof Primitive Portuguese Home By Artspazios View in gallery

This house project in Viseu, Portugal is nice. The project covers over 7,300 square feet, making it the largest one on the list. The tones and vintage design make it special. 

The house has a flat roof and deck on the upper levels. The style is like a hotel or apartment that allows roof access. 

Frequently Asked Questions (FAQ)FAQ

Can I Put A 3D Printable Flat Roof On A Mobile Home?

Yes, you can install a 3D printable flat roof on a mobile. It’s easier than you think. Mobile home roofs are rectangular. They do not have a variety of designs. 

Most flat roof designs are under 10 feet. 

Can A Tiny Home Have A Flat Roof?

Flat roofs are perfect for tiny homeowners looking for an easy and inexpensive, yet durable roof for their property. While tiny house flat roofs have lots of benefits, there are also many things to be aware of.

Should I Install Drain Scuppers On A Flat Roof?

This would be a great idea. The good news is that it’s easy to do. Installing drain scuppers is a fun DIY home project. 

Scuppers function as a draining system for your roof. They carry the water to the edge of your roof where it falls to the ground. The wider the scupper the better because it won’t become clogged with leaves and other debris. 

Can You Put A Flat Roof On A Pergola?

Yes, you can. Installing a flat roof on a pergola is a fun backyard DIY project. You want to use clear corrugated polycarbonate roofing panels. Lay the panels on top of the pergola roof. One nice feature about the panels is they’re cheap.

The panel direction on your pergola will be the same as your home if it’s attached or has a slope. During installation, point the grooves downward and away from your home.

With free-standing pergolas, make sure you pitch the middle of the roof, so you won’t have a puddle problem after it rains or snows.

Can I Install A Parapet On A Flat Roof?

A flat roof by design will have a parapet. They protect your home from wind, rain, and hurricanes. Parapets also prevent your home from collapsing. 

If your flat roof doesn’t have a parapet, you can install Canales, otherwise known as roof scuppers. Canales are drain spouts that protect your roof from water build-up.

What Is A Flat Roof And What Is It Made Of Conclusion

The flat roof is back. The roof style is cheaper and durable than earlier designs. Before you choose a style that fits your home, do some research.

Installing a new roof is not a DIY home project. You’ll need a professional contractor. They’re easy to find. All. Need to do is search for a “general contractor near me” and you’ll find one.

Your environment is the most important thing. Flat roofs are best in calm weather climates. If you live somewhere that has heavy rainfall or snow, you might want to consider a different roof style.