Building Flat Roofs

Building Flat Roofs

But a lot of devil is in the detail that makes all the difference when it comes to the quality and lifespan of the roof that is built.

Essentially, you have the roofing timbers, joists or steels that support the roof and then the actual flat roof on top.

This can be something very basic, with a limited life span that might keep a shed dry for a few years, or a roof that is suitable for a large commercial building such as blocks of flats or offices. They might both be flat roofs, they might both have a roof laid across the support structure, but beyond that there are few similarities.

At Topseal, when building flat roofs we only deal with quality GRP (fibreglass) flat roofs that are designed to last a lifetime and have guarantees that last for decades (40 years on materials and workmanship for some roofs). It is this quality of roof that we will focus on for the rest of this page looking at flat roof construction.

Building a Flat Roof – Plenty of Layers


For standard requirements, typically the roof for most commercial or residential needs, multiple layers are required.

Using our standard Topseal roof as an example, this has a 12mm ply subdeck, then insulation, and then an 18mm deck. On top of this, there are then the waterproofing elements, roofing resin, a 450g/m2 reinforcement mat, another layer of roofing resin to saturate the mat and then the topcoat layer.

To this, detail and trim can be applied, this including a range of colours that ensures the roof fits in with any property.

This quality of roof – fitted across millions of square metres in the UK – is suitable for the majority of projects, common examples shown in our Case Studies. There is a 25-year guarantee, with the roof expected to last a lifetime.

For projects where the roof to be built needs to cope with more extreme conditions, or cope with heavier footfall, the Topseal HD is an example of flat roof construction designed to cope with severe demands. The basic building remains the same, but the Topseal roofing grade reinforcement mat is 600g/m2.

Even for the Topseal Double Top, the building follows the same basics, this roof though has two layers of roofing mat, and creates a roof that is suitable for balconies and walkways. It is also a roof with a 40-year guarantee – so one that is designed for the heaviest footfall yet also has a guarantee that lasts for many decades.

Flat Roof Building  – The Devil is in the Detail


Others, though, follow similar basics. What makes the flat roof construction of some stand out against the competition?

The difference is in the quality of the manufacture, installation and materials.

While we cannot talk for the quality of others, for Topseal we can say that:

  • Our roofs have been fitted since 1992 and have been installed across millions of square metres of UK roofing,
  • All built flat roofs have lengthy guarantees – from 20 years up to 40 for materials and workmanship
  • All our roofs are cold applied, so there is no danger of damage being caused to the structure
  • Topseal has full BBA Approval
  • Topseal is both ISO 9001 and 14001 accredited
  • The roofs are only ever installed by approved, trained, verified installers (given the length of our guarantees, it is essential the fitting is always to the highest standard)
  • The versatility of the range makes Topseal suitable for everything from garages, extensions and porches through to simulated lead replacement for heritage and listed buildings and large-scale commercial projects
  • Topseal has a replacement roof product – Direct Lay can be applied over failed roof making it completely watertight, this saving both expense and upheaval.

Which type of flat roof construction is suitable?


In the majority of cases, a flat roof such as Topseal’s standard product would be suitable, this used across domestic and commercial properties.

However, when there is a requirement to cope either with heavier footfall or more extreme conditions, it might be that a roof with additional layers or thicker roofing grade reinforcement mat can be more suitable.

Please take the time to look around this site to get more of a feel for Toposeal, the UK’s leading flat roofing solution.

If you would like to arrange an obligation free site visit from an approved Topseal installer to assess the requirements for your flat roofing needs, and to provide a quote for consideration, please get in touch by calling on 01423 886495 or use our Contact Form.

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