PVC Flat Roofs


Just a Quote: Expert advice without the hard sell

PVC Flat Roofs

As with all home improvement products, roofing systems on both flat and pitched roofs will eventually come to the end of their functional life and will require either repair or replacement. The cause of the failure of flat roofs should be properly investigated so that the design of the new flat roof installation prevents similar problems from re-occurring and the appropriate remedial or replacement work can be specified.

In addition and where applicable, compliance with Building Regulations is necessary, especially the Approved Document Part L which deals with conservation of fuel and power, hence the requirement for the correct level of insulation in flat roofs, whether they are for repair and refurbishment, a planned installation or in a new build situation.

Sika Sarnafil™ PVC Flat Roofs

It is virtually impossible to refer to PVC flat roofs without mentioning Sika Sarnafil™ single ply PVC roofing systems, the installation of which is offered to the domestic home improvement market and the commercial market under the Roof Assured™ banner. Sika Sarnafil™ is part of the international construction company, Sika AG and since its inception in 1980 Sarnafil™ claims to be the UK’s market leader in single ply flat roofing systems in respect of new and refurbishment projects for both domestic and commercial markets. Sarnafil™ single ply PVC roofing systems provide a complete roofing solution with a BBA (British Board of Agrément) certified life expectancy of over 40 years.

Sarnafil™ single ply PVC roofing membranes are available in a range of colours including light grey, lead grey, copper patina, azure blue (RAL 5009), window grey (RAL 7040), copper brown (RAL 8004), traffic white (RAL 9016) and solar reflective (RAL 9016).

PVC Flat Roofs – Sika Sarnafil Roof Assured™

Sika Roof Assured™ specialises in the installation of Sika Sarnafil™ single ply PVC roofing systems for the domestic market and although the product is extensively used for commercial roofing, most of the information in this website is tailored for the homeowner. Sika Sarnafil™ single ply PVC roofing systems can be used to replace an existing roof which is leaking, one which has reached the end of its functional life, or for new build projects. It is easy to assume that this type of roofing product is only suitable for flat roofs but Sika Sarnafil™ single ply PVC roofing systems can be used on roofs with a pitch of up to 35 degrees.

Approved installers of PVC flat roofs

The real advantage of using this roofing system is that it combines the excellent characteristics of being virtually maintenance free and aesthetically pleasing, with the fact that it can only be installed by approved, registered installers who have undertaken the Sika Roof Assured™ training course at the Sarnafil Training Academy. Sarnafil roofing membranes can be used on garages, conservatories, balconies, dormers & bay windows and they have been featured on television programmes such as Grand Designs & the Property Ladder.

All Roof Assured installations come with a 15 year guarantee covering the membrane and any other associated Sarnafil products used, backed by independent insurance cover. In addition, Roof Assured’s own Five Point Pledge includes a quality installation, aesthetic appearance, environmental friendly products, the guarantee and value for money. It is no wonder then, that (according to Sika™) Sika Sarnafil™ single ply PVC roofing systems are the single most specified flat roofing material by the UK’s leading architects.

PVC flat roofs – Refurbishment Options

Sika Sarnafil™ offers two types of roof refurbishment depending on the condition of the existing roof – Overlay or Strip.

PVC flat roofs – Overlay

Subject to the condition and the materials which have been used in its construction, it is occasionally possible to install the Sarnafil roofing membrane over the existing roof. This is only possible where the timber deck and insulation have not deteriorated due to water ingress and by allowing the existing roof structure to remain in place it is the least expensive option.

PVC flat roofs – Strip back

Stripping back the original roof to its supporting structure is by far the most common method of installing Sarnafil roofing systems due to damage which will normally have occurred to the timber decking and insulation. The old roof is removed back to the joists and a new structural deck is installed, followed by a vapour control layer, the necessary insulation to comply with current Building Regulations and the Sarnafil roofing membrane.

PVC flat roofs – Commercial Projects

From a commercial point of view, Sarnafil™ roofing membranes have been specified for a wide range of high profile commercial projects including St. Pancras Railway Station, Heathrow, Gatwick & Stansted airport passenger terminals, the Bluewater and Arndale retail centres and Arsenal Football Club‘s Emirate Stadium.

Advantages of Sika Sarnafil™ single ply PVC flat roofs

PVC flat roofs – Quality

Sarnafil PVC roofing membranes are manufactured in Switzerland under a strict quality control programme to ISO 9001 and are manufactured to the standards of ISO 14001.

PVC flat roofs are dimensionally stable

Sarnafil PVC roofing membranes have a reinforcement carrier sheet which means that they do not shrink, stretch or otherwise lose their shape.

PVC flat roofs are solar reflective

The international standard for testing of waterproofing membranes requires exposure tests to 5,000 hours of UV exposure – Sarnafil membranes are tested to withstand 10,000 hours of UV exposure. Sarnafil membranes are UV resistant and require no additional protection from the sun’s rays in the way that bitumen felt utilises aggregate chippings.

PVC flat roofs have a lacquered top coat

Sarnafil membranes have a lacquered coating which helps to provide protection against industrial & biological waste and air pollution.

PVC flat roofs are resistant to root growth

Sarnafil membranes are resistant to plant root growth which makes them suitable for use in green roofs where grass and shrubs can be planted on a ballasted roof.

PVC flat roofs are fire retardant

All Sarnafil roof membranes are self-extinguishing, having been treated with a fire retardant which satisfies relevant Building Regulations.

PVC flat roofs are vapour permeable

Being vapour permeable, all Sarnafil roof membranes ‘can breathe’ which allows trapped moisture and condensation to escape. This prevents blistering and slumping which is common in flat roofs and results in degradation of the surface.

PVC flat roofs have a flame free installation

Sarnafil roof membranes are welded with hot air to form joints which are even stronger than the membrane itself which means that they can be installed without using naked flames.

PVC flat roofs have a low environmental impact

Sarnafil roofing membranes have a low environmental impact and when used in conjunction with effective insulation materials can improve the energy efficiency of your home.

PVC flat roofs have a long life expectancy

Sarnafil roofing membranes have been installed on buildings since the 1960’s and many of the roofs are still functioning today. The membranes have been independently assessed by the BBA (British Board of Agrément) to have a life expectancy of over 40 years.

Photovoltaic (PV) Solar Roofing Systems and Green Living Roofs

Photovoltaic (PV) PVC flat roofs

Sarnafil™ roofing systems can be adapted to take both Solar PV and Solar Thermal installations which can be used to provide a renewable energy source, read more…

Rigid solar PV panels can be installed on a Sarnafil™ roof though consideration should be given to the weight of the installations and also the fixing method to ensure there is no water ingress through the roof.

Solar thermal collectors can also be installed on a Sarnafil™ roof in order to heat water in a storage tank via connecting pipes. The heated water can be used for domestic and industrial purposes including under-floor heating, space heating or swimming pools.

PVC flat roofs can be green living roofs

Sarnafil™ offers three types of green roof, all of which are built on a ballasted roof: –

1. SarnaVert™ Extensive

SarnaVert™ Extensive green roofing systems provide lightweight planting on a thin layer of ballast (65 mm – 150 mm) for extensive plant cover with little maintenance. They can support grasses and mosses which can establish self-sustaining plant communities on roofs with slopes up to 35 degrees.

2. SarnaVert™ Biodiverse

SarnaVert™ Biodiverse Green Roofing Systems are designed to enhance the local requirements of flora and fauna, taking into account any environmental objectives and planning constraints. They require little modification to the roof, are generally self-sustaining and, planted on a thin layer of ballast (65 mm – 150 mm) can be used on roofs with slopes up to 35 degrees.

3. SarnaVert™ Intensive

SarnaVert™ Intensive Green Roofing Systems can support turf, perennials, shrubs and trees to create a traditional garden at roof level. Normally they are laid out in sections with footpaths and seating areas catered for but will require intensive care and maintenance in addition to irrigation.

Just a Quote 

A survey of a flat roof in need of refurbishment will include measuring and assessing the condition of the roof, providing information on the four main types of flat roof replacement products and advising which ones are suitable for your particular circumstances. The vast majority of installation companies which offer flat roof refurbishment only offer one of the options and they will be naturally biased in favour of their own product. We offer an independent, unbiased assessment of the work required on your flat roof and provide guide prices for each of the appropriate methods of repair. At worst you may save a few pounds but at best you could avoid having the wrong product fitted.