warm and cold flat roof constructionCovering a flat roofing is a whole different animal than tiling a pitched one. On a flat roofing, normally speaking, you ideally want to prevent any kinds of joints if at all possible. The biggest threat is naturally going to be water, which WILL find any access though any hole or inadequately-sealed joints in the roof membrane. Your main goal when covering a flat roofing is to develop a barrier that will be impenetrable to water.

When it comes to covering up a flat roofing, your options are both restricted and extensive. What that implies in a nutshell is that your traditional roof materials such as asphalt shingles, concrete tiles, and corrugated metal are out of the window. That being said, flat roof systems such as PVC, TPO, EPDM rubber, and others, each provide their advantages and disadvantages.

So why can’t you put standard roof materials on a flat roofing system? Well, technically you can, but they are practically guaranteed to leak. Systems like asphalt shingles and concrete tiles are set up by overlapping one row on top of another. They work cohesively with the pitch of the roofing system to shed rainwater and snow as it falls from the sky. Since flat roofs have little to no pitch, the water would work itself below the shingles or tiles, ultimately decaying the substrate and triggering leakages on your interior.


How do you make a product (besides a roofing system) impenetrable to water? You can either use something physical such as a tarp, or coat it with a material to produce a barrier like you would through deck stain or lacquer. Roofing systems follow this same property– either physically cover it with something like a PVC membrane or use a finish such as tar or spray on silicon.

Why Do Flat Roofing systems Exist?

Developed Up Roofing (BUR)— better understood by their ‘street name’ of tar & gravel roofs, BUR is simply that. Developed up roofing can consist of up to four plies or more consisting of alternating layers of bitumen (asphalt, coal tar, or other adhesive) with a topping aggregate layer of gravel or other products. Developed roofings have been in use for over 100 years with their greatest benefit being the ability to hold up against heavy foot traffic. Membrane roofings are long lasting … in a sense, but a gravel coating can withstand heavy accidents. The downfall is obviously the included weight requiring support to the supporting structure.


PVC Single-Ply Membrane— perhaps the most popular of all flat roof products (some professionals even install ONLY PVC membranes.) PVC membranes are a single layer of thermoplastic product. PVC roofs are especially strong and durable, including a minimum snapping point of 300 pounds per inch compared with the industry-recommended 200 PPI. Seams are heat-welded (hot air welded) to form a watertight bond. The bonded joints are actually stronger than the material itself! Many PVC membranes, particularly white-colored ones are extremely energy effective, since they reflect the sun’s energy instead of absorbing it. The PVC membranes frequently come with life time service warranties.

PVC flat-roof.

Obviously, any roof’s primary job is to create a barrier of protection in between the structure below and the environment above. Therein lies the conundrum related to flat roofing. For all the looks and convenience, the design does not do a lot to prevent snow and water buildup.

PVC Membrane— perhaps the most resilient of the single-ply membranes with a lifetime warranty, however likewise very pricey.

EPDM— budget friendly, however not as long lasting as PVC.

TPO— an energy effective membrane, however a new technology requiring skilled professionals.

Modified Bitumen— multi-layers, however also heat soaking up and tough to set up.

BUR— compliant with heavy foot traffic however very heavy.

Silicon spray— smooth setup, but costly.

To find the best flat roof material you truly need to consider the most common issues your roof will deal with (great deals of traffic, unstable environment). You’ll, of course, also have to consider your budget plan.

To be reasonable, flat roofing systems aren’t completely ‘bubble-level’ flat. They work in similar way as a rain gutter system, angled slightly or pitched a couple of degrees, so that water streams into a downspout. Even so, flat roof products have to have the ability to take in the force of the weather condition and to endure ponding water or snow and ice until it melts.

The life period of your flat roofing system depends upon a great deal of various aspects starting with correct setup. If your climate has fast changes that see Spring, Summer, and Winter in the exact same week, the material will be put under more tension which will minimize its life period. A roof that is accessed a lot will also wear down much faster. Here is what you can get out of the popular materials in terms of longevity:.

Completion goal is to avoid leakages on a flat roof, thankfully you’ve got a great deal of various routes that can get you there!.

Labor costs will vary depending upon your area. You can get a great idea of the estimated expense to cover your flat roof based on the typical product prices.

PVC Membrane— aside from the membrane itself, an insulation board need to initially be installed to assist with energy costs. The membrane is installed in rows (6-18 ′), each which need to be hot-air bonded at the seams. Lots of professionals pick to mechanically fasten the edges to help avoid uplift, all of which add to labor expenses. 

EPDM Rubber— makers attempt to prevent joints with EPDM membrane sizes that can reach 50 ′ large by 200 ′ long. These big pieces are terrific for preventing possible leaks at the seams, however these wide rolls are likewise extremely challenging to deal with during the installation. The EPDM membranes set up like a giant sticker label but needs to be done gradually and with accuracy to prevent bubbles. 

TPO— insulation boards are first secured to the roof substrate. TPO also comes in rolls and can be mechanically attached to the insulation boards or set up with the self-adhesive. 

Customised Bitumen— customized bitumen is set up in multiple layers, each of which is torched to the surface below at every 1/4 turn of the roll. This is a very labor extensive procedure that definitely need to be carried out by an expert. This type of roofing system does have cold-rolled technologies offered now also however it involves a great deal of application of roofing tar.

Developed Roofing system— installation includes applying numerous layers of ply sheets that are bonded together using hot asphalt. The top layer can be a reflective finish for energy efficiency or gravel for included durability. 

Spray-On Roofing system— applying a spray to a roofing system sounds easy. The product can be used right over an existing roofing system so little to no preparation work is needed besides cleaning. It’s still important to apply the spray evenly and delicately however. The product itself will also figure out the cost as polyurethane foam can be applied for just £3 per square foot and acrylic $6 per square foot. Silicon is the agreed upon premier spray application, but the product expenses can drive setup prices up to £9-£ 10 per square foot or more.

Picking an appropriate flat roofing material is a two-part procedure. On one hand you dream of a compound that has good looks while fitting within your budget plan. You likewise need to know the product will last:.

Products Life-Span.

Whether you have an industrial or domestic building, some type of roof covering is 100% obligatory. There are 5-6 various paths to take concerning the materials needed for roofing a flat surface:.

PVC– 15 to Thirty Years.

EPDM– 10 to 15 years.

TPO– 7 to Twenty Years.

Bitumen– 10 to Twenty Years.

Developed Roof– 15 to 20 years.

Spray-On– as much as 20 years.

So, how will you select which roofing product is ideal for you? It’s advised to meet with numerous roofer so that they can examine your precise scenario and the specific surface area requiring a finishing. If an old roofing just requires replaced it will direct the choice as will if the roofing system is going on brand-new construction. The specialist will lay out your alternatives, then you’ll discover the finest choice based on your budget plan, location, and the capability of business in your location to properly set up each product.

Prior to we get into contrasts of various flat roofing products, it’s essential to understand why they exist in the first location given that they’re apparently such an inconvenience and an almost-immanent leakage danger. There are 2 main reasons behind why a contractor would require a flat roofing system– 1) aesthetics and 2) convenience. For instance, when you’re including on to a house (building an addition) with something like a three-seasons room, a flat roof merely looks better. Residences with unblended roofing system pitches can be an uncomfortable eyesore. In business buildings, flat roofings, outright, offer an easier place to set up outdoor COOLING AND HEATING units instead of putting them in high-traffic ground locations.

Here’s a fast suggestion of each material’s pros and cons:

So it appears that you have choices when it pertains to applying a material to your flat roof. How do you make the decision on which type to go with though? There are some important aspects to think about such as convenience of installation and how eco-friendly the manufacturing procedure is, however for most customers the 2 essential decision makers are cost and performance.

. Silicon Spray– an example of the protective finish set up on a roofing is a silicon spray. The most significant benefit of a spray on roofing system is foregoing any joints like you have with membranes. One would assume that spraying on a roof material would be much more economical than applying a physical material, however in truth the silicon covering is among the most expensive roof procedures.


EPDM– frequently understood in the industry as a rubber roofing system. Among the greatest benefits of EPDM over a PVC roofing membrane is a much lower price. PVC and EPDM usually go 1-2 in regards to popularity for flat roofing depending on what area you live in. The seams of EPDM are not as strong as the PVC, heat-welded joints either. EPDM also tends to soak up heat, which can drive up energy bills for the property owner.

TPO– another single-ply roof membrane that chemically bonds rubber, ethylene, and propylene as well as numerous filler materials. TPO roofs have actually been significantly growing in appeal since their intro in the early 1990s. Part of what is sustaining their recent rise is energy-efficiency, as they are quicker offered in white and light gray (in addition to black) compared with their closest rivals PVC and EPDM. TPO is stated to provide the very best of both EPDM and PVC in one plan. The material is better to a rubber roofing in expense, however also includes welded appears for durability like PVC membranes.


It’s easy to assume that a flat roofing system would be far less expensive to use material to than a pitched one. For gain access to reasons alone it would seem it’s a lot much easier to roofing a flat surface area then one that is steep and requires harnesses and braces to walk around. Lots of roofer will inform you though that dealing with flat surface areas is actually harder on the back. Take into consideration that flat roofs often require the application of adhesives and some types such as modified bitumen are installed with a torch that warms up the seal. Labor costs can be simply as high for a flat roofing system as they would be a 10/12 pitch.

For more information about Flat Roofs and how to avoid the potential perils of flat roofing, please click that link.