FAQ

Our approved roofing products can all be used to overlay an existing roof, saving time, money and avoiding unnecessarily exposing the roof to the elements during the installation process. When using one of our approved EPDM systems, this can be achieved through cleaning and priming the existing roof surface, before installation. In some cases the existing roof may need (or you may want) to first be overlaid with insulation (minimum 25mm), or ply boarding (4mm or 8mm), on top of which we can directly lay the EPDM membrane. Another point to note is that our choice of EPDM has a permeable membrane which allows any existing moisture to escape, while remaining 100% waterproof stopping water and moisture from getting in. When using our approved silicone roof coating, we can overlay the existing roof after cleaning the roof and applying special tapes to the existing roof joints. However, when overlaying a silicone coating onto  ply boarding, an extra coat will be required as the first coat is partly absorbed by the board.

In most cases when using one of our approved EPDM roof membranes or silicone roof coatings, we can overlay on to existing materials and roof surfaces. This means apart from any existing leaks, your roof remains watertight throughout the installation process.

Yes! The flat roofing products on our approved list all offer 20 Year Guarantees directly from their manufacturers. However, in terms of how long your roof should realistically last would lie somewhere in excess of 50 Years. Why is this? Well, take EPDMs for example. The first buildings to be covered with EPDM systems were over 50 Years ago, and still they show no signs of deterioration.

The products we choose to use are either made to measure in the factory (so if your roof is less than 30m by 15m it can usually be installed in one piece), or are liquid applied. This means there is little to no joining carried out on site when using EPDM roof membranes, and no joining whatsoever when using silicone roof coatings. Considering joins are the most susceptible area to problems and leaking, you can be rest assured your roof is built to last.

Obviously as with any outdoor work, weather plays a big part in the time frame, as does the size of your roof, complexity (number of penetrations) and the nature of the works you require (i.e. overlaying vs replacement, insulation, rain water goods etc). Due to this we cannot give you an exact answer! However, we have a stringent list of criteria we use to choose our flat roofing products, and one important criterion is speed of installation. Along with using the right quality products, professional workmanship is what gives us an advantage. This allows us to use our knowledge and experience in the industry to install roofs very quickly. As an idea, when using one of our approved EPDMs, we can install a flat roof approximately 60-70% quicker, compared to using most other roofing materials, due to both its manufacture and installation process.

The short answer is NO! The long answer is that unless another product is already specified, S&K Contractors will always provide a quote using one of the flat roofing products on our approved list. These include EPDM roofing systems and silicone roof coatings, which don’t require any naked flames or heat during their installation process. Should another product be specified where heat is required, we can discuss any concerns with you.

Stay calm and don’t panic! With an EPDM rubber system it is usually a quick process to repair and is as simple as putting a patch on a bike tyre. Due to its characteristics, EPDM rubber can withstand environmental conditions such as temperatures ranging from -40 to +110°C and is UV stable. This means it will not deteriorate or degrade, so this process can be done 1 day after installation or 50 years later.

Compared with felts, EPDM rubber roofing systems will last 5 to 6 times longer, without using naked flames or heat to install the product. Also our selected EPDM product, nor its seams will fail after exposure to the elements, and there will be no weaknesses around corners or other protrusions on the roof. EPDM rubber is permeable, stretches to accommodate any building movements and is not as reliant on the quality of workmanship for joining on site. On top of this, EPDM rubber systems come with a 20 Year Guarantee and have a proven life expectancy in excess of 50 years!

We have also noticed an increasing trend. People that choose to go for other options on their roof (in particular felts and traditional systems) as they were slightly cheaper at the time, end up returning to us after a few years when it has failed to keep the building dry. Don’t be one of these people. Make sure you use the right system in the first place.

Cold bonding is the process we use to join EPDMs on site using our extensive selection of adhesives. It is safer than hot bonding as there is no heat required and is just as strong when completed. This also allows our fitters to carry out detailing works using pre-formed sections.

Some EPDMs offer already made pre-formed external corner pieces & pipe sleeves in a range of sizes, which can then be bonded to the sheet allowing the obstacle to be protected and water to flow freely, without compromising the integrity of the EPDM sheet. In all cases EPDMs are extremely flexible, and custom shapes and angles can easily be accommodated for on site, if and when required.

With silicone coatings, as they are liquid applied, they will be able to mold to any shape and around any difficult or awkward roof penetrations.

Yes. EPDM rubber roofing systems are very green. They use no plasticisers or PVC’s, and are completely natural with a low use of global resources. They also have a low use of energy compared to bitumen products during their manufacture, and are completely recyclable.

No. Despite EPDMs' green characteristics and the many technical advantages it has over other roofing products, it is still competitively priced on smaller roofs and much cheaper on larger flat roofs (primarily due to its manufacturing and installation process). Not only is it competitively priced in the shorter term, but due to its hug life span, it is considerably cheaper in the longer term.

Ethylene Propylene Diene Monomer. For a better description of EPDM see the EPDM rubber roofing systems page.

When a silicone roof coating is installed by a competent flat roofing contractor, it offers a low invasive and minimal noise installation process. This is because a quality silicone system can be used to overlay the existing roof structure in most cases, and ultimately avoid the need to rip up the existing waterproofing material which would expose the building to the elements and cause sections of the building to become unsafe, or noise polluted. Along with this, the product is liquid applied and therefore naturally offers a less disruptive installation process.

While it is true that silicone roof coatings are indeed slippery when wet, there is no need to count them out just yet for high traffic flat roofs. The preferred system we use offers a silicone based, solvent free, yellow sealant product which we can use as an alternative to conventional walk way roofing mats. In our experience we have found this to be a great solution towards solving this problem. This provides a great amount of traction, allowing maintenance staff or pedestrians access to the roof. Should you still be unsure, why not consider using an EPDM rubber roofing material, or Contact Us for free help and advice.

This is achieved through the bright white colour of silicone roof coatings reflecting away up to 85% of the sun’s heat rays. This reduces the internal temperature of the building allowing it to remain cool, which is especially important during the summer months. This effectively reduces the need to run the buildings air conditioning. The amount of reward in terms of efficiency will depend on some factors such as temperature, the insulation and the previous roofing product used. For example metal buildings and buildings with dark coloured roofs such as felts and asphalts can have a significant difference when a silicone coating is applied, and thus make them more comfortable for their occupants.

When using a silicone roof coating system, roofs can require up to 50% less installation time when compared with most other flat roofing and low pitched roof waterproofing products and systems.

Yes! While under permanent ponding of water, silicone roof coatings can remain flexible, and able to deal with building movement without cracking or splitting.

Yes, the silicone roof coating can be installed within a wide temperature range, with application being possible between 0°C and 46°C, thus meaning installation is possible throughout most of the winter season too.

That’s correct. Silicone roof coatings requires no primer and can be applied directly to most surfaces ultimately reducing on site installation time and associated costs. As well as this, they require no mesh or fleece, while roof tapes are available to fix cracks, corners and upstands before application.

Silicone roof coatings can be directly applied to the follow flat roofing surfaces:
  • Felt (weathered & aged too)
  • EPDM
  • WPB Plywood
  • Fibreglass
  • Asphalt
  • TPO
  • Steel
  • Concrete
  • Lead
  • Polyurethane
As well as the surfaces listed above, these coatings are suitable to be applied on top of most single ply waterproofing systems, as well as gutters, channels and valleys.