Many homes in the UK have a roof which is either completely flat and partially flat, and although this form of roofing has been popular over the last decades, it’s not without its drawbacks.
Flat roofs are made in a completely different way from traditional pitched roofs with tiles or slates, and are more prone to leaking.
That’s why you’ll find a question about the percentage of your roofing area which is flat when you renew your buildings insurance.
In fact, people who live a house where the flat roof area is more than 40% of the total might struggle to find standard insurance cover.
It looks like insurance companies are going to have to completely change their way of quoting though, as new technology is completely revolutionising the flat roof market.
What exactly is EPDM and why is it different?
Traditionally, flat roofs have been covered in felt and the joints sealed with bitumen.
Although at first the surface is waterproof and solid, over time the felt starts to break down.
Eventually even the most professionally applied felt flat roof will start to leak.
It’s estimated that the average lifespan of a felt flat roof is about 20 years.
EPDM, or ethylene propylene diene monomer to give it the proper name, is a synthetic rubber product.
EPDM has in recent years become the default choice for flat roofs.
If you’re a parent you’ll be familiar with the other common use of EPDM, which in its granular form is used to provide soft surfaces in outdoor play areas.
On the roof, EPDM is a softer, more flexible product than felt.
EPDM also doesn’t need bitumen to seal it either.
Manufacturers will guarantee an EPDM roof for around 25 years.
Most experts estimate EPDM roofs will last longer than that.
Benefits of EPDM Roofs
One of the major advantages of EPDM as an alternative to felt or bitumen is its increased lifespan.
There are several other advantages to using EPDM roofing.
As the material is more flexible, it is easier to use on roof spaces which are uneven or which have skylights or other windows.
It doesn’t break down in sunlight, and is resistant to the most extreme weather conditions.
EPDM does not need to be applied to the roof with heat as felt does, so it is safer to install.
Manufacturers make EPDM sheets big enough to cover an area of up to 50 square metres in a single sheet.
This cuts out the need for joining sheets completely and lessens the chances of leaks.
It can also be a more cost-effective choice than felt for your flat roof.
Costs of EPDM Roofs
One criticism levelled at EPDM roofs is that they are more expensive than felt flat roofs, and if you look at the price of the material on a per metre squared basis, that is probably true.
When you are talking to roofers about the cost for replacing your roof they will calculate their costs depending on the size of the roofing area, taking into account their labour, materials and other costs such as scaffolding.
You can expect to pay around £80 per square metre for an EPDM roof, compared with £50 for a felt roof.
This may seem like a big difference in price, but it’s also important to factor in how long you expect the roof to last.
Spending more initially on an EPDM roof might mean you get a product which lasts twice as long as felt, and doesn’t need repairing when it starts to degrade.
In the long run, investing in a new EPDM roof rather than simply replacing a felt one with more of the same is well worth the money.
Can all roofers use EPDM?
EPDM has become very popular in recent years and it’s therefore unlikely that you’ll come across a roofing firm which does not know how to use this product.
Some may refer to it as a brand name like RubberCover or RubberGuard, which are brands used by the manufacturer of EPDM, Firestone.
When you are asking local firms to quote for replacing an existing flat roof with a new EPDM covering, always check that they have completed similar projects in the past.
A good roofing firm will not hesitate to give you references and be happy to talk about similar jobs they have done in the past.
Use this information beside other variables such as price and reputation to help you compare the quotes and decide which one offers the best value for money.
Remember – always get at least three quotes from roofers in writing, and never agree to pay anyone the full amount for the job up front.
Ask friends or family to recommend roofers who they have worked with successfully in the past.
You can also check out the local listings on Top Tradespeople to help you draw up a shortlist of companies to approach for a quote.
How Long Will it take to Fit My New Roof?
The length of the job will depend on how much preparation work the roofing firm has to do first before they can get started.
If your roof is difficult to access, they might have to put up scaffolding first.
If the battens and beams supporting your roof also need to be replaced this work will have to be done first, and it will also add considerably to the cost.
Ask your roofer for a breakdown of the project when quoting so that you have realistic expectations about how long things are likely to take.
It’s also usually better to try to plan roof replacement work for the summer months when the hours of daylight are longer and the roofers can work longer hours each day.
If you only have a small section of flat roof, such as on a single storey extension, the job can be done in a day.
Replacing the roof on an entire three bedroom house will take about a week, and if your job means replacing roofing beams and joists, it could take as long as three weeks.