What type of roofing is best for a flat roof

December 6, 2021
"Replacing or installing a flat roof isn’t a decision you want to make without doing some research. As with all building projects, a roof is an investment and as such, questions need to be asked."

Whether you are looking for a replacement or new build installation, you will be wondering: what type of roofing is best for a flat roof?

Replacing or installing a flat roof isn’t a decision you want to make without doing some research. As with all building projects, a roof is an investment and as such, questions need to be asked. Arguably the most important is: what type of roofing is best for a flat roof?

With a myriad of options available, deciding on the best option can be difficult. This is why it is essential that you work out what will suit your needs and budget. 

What type of roofing is best for a flat roof? The options

There are four major material types when it comes to flat roofing: metal roofing, TPO, modified bitumen roofing and uPVC. 

 

Metal roofing

Metal is often used in commercial projects on roofs with a pitch greater than two inches. It is the most expensive option due to the material itself and the expert installation process required. Metal is extremely durable and has a long lifespan of approximately 20-30 years. A metal flat roof will not crack over time.

However, metal is not always impervious to leaks around the seams and roof edges. 

TPO roofing

When considering what type of roofing is best for a flat roof, the term ‘TPO’ will almost certainly come up.

TPO (Thermoplastic Polyolefin) membranes have been used extensively in the roofing industry since the early 1990s. It was thought that TPO would eventually replace PVC membranes; however, this has not happened. They have a decent lifespan – typically around 10-20 years – and have the same energy saving properties you would expect from their PVC counterparts. In addition, as TPO flat roofing seams are heat welded in order to prevent leaks, they tend to need less maintenance. 

However, TPO membranes can be far stiffer, which can lead to issues when installing. TPO roofing’s UV stabiliser is only added to the top surface, so the membranes can only be installed one way up – a problem when it comes to field sheets and upstanding flashings. Plus TPO can produce static when being rolled out and positioned on the roof, attracting dust and potentially compromising the welding process. 

Modified bitumen roofing 

If you were to research into what type of roofing is best for a flat roof, the traditional choice would be bitumen roofing. Bitumen flat roofing was the standard when flat roofs first became popular and it is certainly the most budget-friendly. 

Sadly, this cost saving comes with a price. The typical lifespan of a modified bitumen roof is just 10-15 years. This is because the surface is susceptible to blistering and cracking. Black in colour, they absorb rather than reflect heat, which can lead to UV damage and an overheated room below. 

In addition, standing water can place weight and stress to a flat roof – unless your bitumen roof is 2 or 3-ply (which will significantly increase the cost – you are running the risk of a prematurely aged and damaged roof.

 

uPVC flat roofing 

Flat roofers essex High Tech Membrane Roofing installation

 

uPVC flat roofing membranes are our preferred option every time. Durable, 100% waterproof, reinforced, impervious to UV rays, moss and algae, virtually maintenance-free – it may not be the cheapest option but with our rock solid lifetime guarantee, you will enjoy the ultimate in protection and excellent value for money. 

If you would like to know more about our range of market-leading uPVC flat roofing membranes, please do not hesitate to contact High-Tech Membrane Roofing today. Our team will happily talk you through any questions you may have and arrange a free, no-obligation site visit. 

We hope you found our article, ‘What type of roofing is best for a flat roof?’ of interest. 

Steve Thornton – Author

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