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Flat Roof Terrace

Flat Roof Terrace | Southern Liquid Systems

Are you thinking of converting your flat roof into a terrace? If so, Southern Liquid Systems can help. A roof terrace is a great way to create extra outdoor living space when space is at a premium. Flat roofs in densely populated cities such as London are often used to create an additional living area or a roof garden.

The first step in building a roof terrace is to ensure it is a feasible project for your property. You need to make sure the flat roof of your property is capable of withstanding a roof terrace. This means all the weight of the furnishing and fittings as well as the weight of people. Once you have a professional confirm your roof is capable of functioning as a roof terrace it is time to establish how much construction work is required.

Planning Permission For Flat Roof Terraces

If major construction work is needed you will need to obtain planning permission. Building a terrace on an existing flat roof is an easier project than on other types of roof. This means planning permission being required for the construction of a roof terrace is less likely. It is advisable to check with your neighbours’ feelings before applying for any planning permission and starting construction work. The reason for this is to gauge if they are likely to object to your project. If they do seem unhappy it is better to try and come to an agreement before putting things in process. Once you are sure your neighbours will not be an obstacle you will need to contact an architect to check whether you will need planning permission for your project. A local architect will be an expert in your local council’s processes and will be able to advise you on how you can construct your roof terrace without having any problems with the council. Remember if you build without planning permission you can be ordered to remove your roof terrace so it is imperative to get the correct professional advice.

The Best Waterproofing System for Flat Roof Terraces

At Southern Liquid Systems, we believe a liquid roofing system is the best choice for of waterproofing system for flat roof terraces. It is cold applied meaning no open flames will be used during the installation process. A liquid system also leaves a beautiful seamless finish which can mould effortlessly around complex detailing such as soil vent pipes. This ability to mould effortlessly around details like soil vent pipes and rainwater outlets is extremely important as it makes sure there are no gaps between the point where the roof joins with the pipe. This is not the case if you use a system such as felt. And of course, if there are gaps there is the potential for water ingress and leaks. A liquid roofing system can also provide you with a guarantee of up to 25 years.

The installation of a liquid roofing system on your flat roof terrace will involve the application of primer to the substrate. Any joints in your substrate will be covered with self-adhesive tape before liquid waterproofing commences.

On all corners of your  terrace a liquid waterproofing coat will be applied. Then a reinforced fleece membrane will be cut and place in each corner. Once this is done it will be covered with another layer of liquid waterproofing. Now another piece of fleece membrane of 175mm in width will be cut. This is to be placed so it fits to a height of 75mm on the height of the upstand. Next this fleece membrane is embedded into the coating. It is important here to make sure a layer of liquid waterproofing is applied over all of the fabric including the folds.

On any rainwater outlets, we will cut a length of reinforce fleece membrane which is 50mm longer than the circumference of the outlet. Along this length of reinforced fleece membrane, we will make a series of cuts 20-30mm apart.

Around the diameter of the rainwater outlet we will apply a base coat of waterproofing liquid. Then the reinforced fleece we cut will be placed inside the rainwater outlet hole. And the small cuts will be spread around the diameter. Now we apply more liquid waterproofing around the diameter over all of the fabric and inside the rainwater outlet. We need to make sure the fabric is embedded into the liquid waterproofing coat.

Next, we cut a square of fleece membrane to go over the rainwater outlet. This includes a circle in the centre with a star cut for the rainwater outlet hole. This is place over the rainwater outlet with the star cuts pushed out down into the rainwater outlet.

The same process is conducted for pipe penetrations. We cut a piece of fleece membrane 50mm wider than the circumference of the pipe. We make cuts 20-30mm apart like before. The solid section of fabric without the cuts should be 150mm. This is so it ends up being 150mm above roof level.

The next thing to do is to apply a base coat around the protruding pipe. Then we add the prepared fleece membrane. We put the solid section of the fleece membrane on the pipe itself then spread the finger cuts around the point where the pipe meets the flat roof. Just like last time we now apply the liquid waterproofing coating upon the fleece membrane. Making sure it is all embedded into the liquid coating.

A second piece of fabric is now cut into a square, placed over the pipe and a circle drawn around the circumference. We cut out this circle so the fleece will fit nicely around the pipe. A base coat is applied over the first piece of fabric then we drop the second piece of fabric over the pipe and embed it into the coating. Finally, we apply a top coat over the whole area around the pipe.

We now will apply the first layer of liquid waterproofing to the remainder of the roof. Then roll out the polyester fleece membrane and finally add the top coat to complete the system.

In some situations, you may want an anti-skid layer to be applied upon the completed liquid roofing system. If this is the case it must be done once the liquid roofing system has cured. To do this we tape the area we want to apply the anti-skid layer too. This is normally the perimeter of the roof. We then apply a layer of liquid coating to the area. And then we scatter a generous layer of coloured quartz to the wet coating. This is done until the area is fully covered and no wet patched are visible through the quartz. Now we leave it to dry for two to three hours and then use a brush to sweet away the remaining quartz. Finally, we apply a coat of resin on top of the quartz. This resin is a milky white when applied but is transparent when dry.

Now your roof terrace will be waterproofed. You can start to enjoy your terrace immediately or carry out additional decoration such as decking or patio slabs.

Thinking Of Converting Your Flat Roof Into A Terrace?

If you would like a quotation or to ask any questions about waterproofing flat roofs for terracing please get in touch or call us on 0207 7818153. One of our expert surveyors will be happy to help you.