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Specialist in all aspects of Concrete Waterproofing,  Basement Tanking and Roofing Repairs. 

Waterproofing a Flat Roof: Ensure Lasting Protection!

Updated: Jan 17

Applying protective coatings to a flat roof is the process of waterproofing it to stop leaks. For results that last, the right supplies and techniques are required.

Maintaining the integrity of your flat roof is essential since water damage puts buildings at risk. Unlike its sloped counterparts, flat roofs are more likely to experience water pooling, which poses special issues. You may protect your structure from moisture intrusion, which can result in structural damage, the growth of mold, and insulation issues, by waterproofing it.

It's a procedure that needs to be carried out expertly, with careful planning and the selection of premium materials. There are various choices for waterproofing, each with varying degrees of protection, lifespan, and expense, such as bituminous waterproofing, EPDM rubber membranes, and liquid-applied systems. It is important to remember that routine post-installation maintenance and inspections guarantee the durability of the waterproofing measures. An effective waterproofing plan increases the lifespan of your roof and enhances the general condition of your structure.

The Advantages Of Flat Roof Waterproofing

Waterproofing a flat roof can considerably extend its lifetime. A sealed roof avoids expensive repairs by fending off weather-related deterioration. Water buildup can be prevented by treating your flat roof with waterproof materials. Over time, this buildup may cause serious harm.

The structure of the building is maintained by preventing water penetration. Maintaining a secure and healthful living environment depends on this. Additionally, there is less chance of mold and mildew on a waterproofed roof. If left unchecked, these can negatively impact indoor air quality.

Energy conservation is also aided by waterproofing. An airtight roof saves money on both heating and cooling. By adding another layer of insulation, it does this. Lower utility costs and a cozier interior environment may result from this.

Types of Waterproofing for Flat Roofs

A durable coating is applied to flat rooftops via Liquid Applied Membrane. Experts apply paint to it. As the coating dries, a waterproof layer resembling rubber is created. Water is efficiently kept out by this barrier.

Large sheets are put as a single layer in the single-ply membrane. These sheets, which are usually composed of synthetic materials, are used to cover the roof.

They weld together to form a watertight seal where they overlap. Simple, yet strong.

A waterproof flat roof, ideal for rainy climates, providing reliable protection against water damage.

Bituminous Membrane is primarily composed of asphalt. A surface made of asphalt is tacky and water-resistant. This more conventional approach works well for structures that require a strong defense.

Synthetic rubber is the source of the EPDM Rubber Membrane. Roofers install this pliable covering. After that, they glue or connect it, creating a strong, waterproof cover. It is resilient to inclement weather and long-lasting.

The components of PVC membranes are unique plastics. Roofers apply these durable coatings to protect against water. The seams are heat-welded to guarantee leakage. The PVC weatherproofs itself nicely.

Things to Take Into Account Before Waterproofing

  1. Prior to waterproofing, a flat roof's condition must be evaluated. Inspect for surface deterioration, blisters, and cracks. These issues need repair first.

  1. The choice of waterproofing material is influenced by the local climate. UV-resistant goods are necessary because of the strong sun and frequent rain.

  1. Budget sensibly for waterproofing. Roof size and material quality have an impact on costs. Make sure your investment is in long-term efficacy.

  1. Consider how you use your roof. An extremely pedestrian-heavy roof will require a robust pedestrian surface.

How to Waterproof a Flat Roof in Steps

Waterproofing a flat roof requires careful work. A comprehensive roof check is essential first. Specialists look for wear or cracks. Early problem detection can save costs and time. The next crucial step is surface preparation. This stage entails preparing the roof for waterproofing materials by washing it. The next step is to apply waterproofing material carefully. Water is kept out by this layer. Ultimately, the roof's lifespan is increased by the sealing and protection stage. It entails covering the waterproofing substance with a protective layer.

Typical Issues With Waterproofing Flat Roofs

Because of its design, flat roofs have certain issues. Water ponding and leakage are two frequent problems. Usually, leaking happens when the roof membrane breaks. Further degradation is brought on by ponding or persistent water accumulation. One reason for this stagnant water situation is an incorrect slope.

Poor roof installation can result in both short-term and long-term issues. The efficiency of waterproofing is influenced by installation precision. It establishes how long the roof will last.

A flat roof needs to be maintained regularly for its health. Missing regular inspections might cause damage that goes undetected. This could lead to expensive repairs. Maintaining proper condition requires routine inspections and quick resolution of little problems.

Techniques That Work for Waterproofing Flat Roofs

Waterproof flat roofing system on a flat roof.

For a flat roof, it's very important to pick the right waterproofing method. GRP fiberglass, torch-on felt, and liquid membranes are some of the different materials that have their own benefits. A reliable system should last a long time and not get damaged by water. Knowing how the roof is used is important for figuring out the right thing to do.

Professional workers know how to finish a waterproofing job safely. They promise that the application will be correct, which will stop leaks and other problems in the future. Because they know what they're doing, they can also choose the best method for your roof and the weather where you live.

Things on the list: 

How often to clean up debris?

Check the sides and seams every two years.

Looking at flashings every year and looking for tears or holes every year after major weather events

Maintenance is the key to living a long life. Clean the roof and check it over often to keep it in good shape. Make sure the drain lines are clear so water doesn't build up. Regular checks help find problems early, which means they don't have to be fixed as often and cost more.

How Much It Costs To Keep A Level Roof Dry

How much it costs to waterproof a flat roof will depend on a number of things. Some of these are how hard the job is, how big the roof is, and what kind of materials are used. Prices may also change based on how bad the current roof is and how many fixes need to be done.

Labour costs are affected by how experienced the workers are and how prices change in different areas. The final cost will change based on whether liquid application or sheet

barriers are chosen. Getting several quotes is important to make sure that the prices are fair.

Roof Size (sq ft)

Low-End Cost (£)

High-End Cost (£)

500 - 1,000



1,000 - 2,000



2,000 - 3,000



Common Questions About Flat Roof Waterproofing

What is the best way to waterproof a flat roof?

Renewing waterproof flat roof with magic asphalt.

Using a waterproof membrane is the most effective method for waterproofing a flat roof. Polyvinyl chloride (PVC), asphalt (or coal tar), ethylene propylene diene monomer (EPDM), and thermoplastic olefin (TPO) are among the many membrane options. To prevent water from getting into the roof, these materials are coated to the surface and then sealed around any penetrations and edges.

What are the waterproofing solutions in flat roof?

Flat roofs can be waterproofed in many ways. Used roofing membranes, such as EPDM, TPO, or PVC, are among the most prevalent ways. In addition to being long-lasting and pliable, these materials are also resistant to heat and ultraviolet light. The typical installation method involves heat welding or adhering huge sheets together to create a continuous waterproof barrier.

What is the best DIY flat roof covering?

Consider your needs, your budget, and the local environment when deciding on the finest flat roof covering for a do-it-yourself project. Nonetheless, modified bitumen roofing and EPDM rubber roofing are two favourite choices.

Do you need a membrane on a flat roof?

A flat roof absolutely requires a membrane. Water pooling and leakage are more common on flat roofs than on sloped ones, thus an additional layer of protection is necessary. The membrane's waterproofing properties keep water outside of the building and away from its structural components.

Is acrylic good for roof?

The versatility and long lifetime of acrylic make it an excellent roofing material. Extreme weather, including snow, intense rain, and solar rays, has no effect on it. Because of this, it is a great option for places that experience really severe weather. Acrylic roofs are also easier to install and won't put as much stress on your home's framework because of how light they are.

How do I protect my roof from rain?

Protecting your roof from rain involves regular maintenance and preventative measures. Firstly, ensure your gutters are clean and free of debris. Clogged gutters can cause water to overflow and seep into the roof structure, leading to potential damage. Regularly inspect your roof for any signs of damage such as broken or missing tiles which need immediate replacement to prevent water infiltration.

In summary

You must protect your flat roof from water damage if you want it to last. You can safeguard your investment by using high-quality materials and professional procedures. Consistent upkeep guarantees long-term effects. Get a long-lasting, leak-proof roof by starting the waterproofing process today. reach out to us at or 07921 517860. Our helpful, knowledgeable team is always happy to lend a hand.

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