Flat Roof Renewals

Flat Roof Renewals

Here at Top Rank Roofing and Building Ltd we offer two types of flat roof systems: the three layer mineral felt system and the cure-it fibreglass system. Both of these roofs come with a guarantee however the fibreglass roof guarantee is substantially bigger. There are two types of roof that can be installed using both these finishes and they are a warm deck roof and a cold deck roof. This is a step by step guide on how we will replace your flat roof.

Strip your existing roof

Firstly your existing roof will be stripped back to the rafters. All old materials will be put into bags and taken away in one of our vans however if your roof is too big then a skip may be required. This step only applies if you are replacing a roof.

Changing the rafters

This step only applies if you need your rafters changed or you are having a roof put on a new building where there wasn't any before. We will secure rafters to your roof, size 6x2 at a gap of 18 inches apart (this is standard). On top of these rafters we will install timber furrings which will be from a thickness of 2 inches down to nothing to make sure the roof is running towards the gutters or drain.

The next step will depend on which type of roof you are having

Pick a roof type

Warm deck roof

A warm deck roof will consist of three layers, not including your top finish. The first layer is a layer of 11mm OSB board which is attatched to the rafters. Then a layer of 100mm extratherm insulation is added on top to insulate the roof and keep the heat it. The final layer is a layer of 18mm OSB board which goes on top ready for your top finish.

Cold deck roof

If you are having a cold deck roof then the first step is to install plasterboard from the inside if there isn't any already. After a layer of 270mm rockwool insulation sits inbetween the rafters. The final layer is a layer of 18mm OSB board ready for your top finish.

Pick a Finish

Three layer mineral felt system

After your timber and insulation has been installed it is time for your waterproof covering. The three layer mineral system consist of two layers of underlay and a layer of mineral felt. The first layer of underlay is burned of using a roofing gas torch powered by propane gas. The second layer of underlay is burned on rolling in the opposite direction to the first layer. The final layer of mineral felt is then burned on.

The cure-it fibreglass system

The more modern way of covering a flat roof is using a fibreglass system so here at Top Rank we use the trusted cure-it system. Firstly the fibreglass trims are put on which come in different shapes for different jobs, then a layer of resn is rolled over all the seems and joins followed by a fibreglass bandage, an additional layer of resn is layed on top of this then the air is taken out using an air paddle. After a layer of resn is rolled onto the main roof followed by a fibreglass mesh, this is also followed by an additional layer of resn then the air is taken out using an air paddle. After this has been left 24 hours to dry a waterproof top coat in the colour of your choice is applied.

About us

At Top Rank Roofing, our priority is you. Our market-leading service means that we focus on every aspect, whether we are listening to your ideas, manufacturing products according to your requirements, or offering solutions to any problems along the way. We aim to help you successfully achieve a result that you can be proud of for many years to come!


Partnering closely with each individual to ensure that the most effective, cost efficient and environmently friendly engineering solutions are delivered every time.

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