Bespoke Applications

Why roof sealants perish over time – and how to prevent this happening...

Whether a gulley or duct is sealed with a preformed membrane, torch-on felt, or an applied liquid membrane it is presented with one major challenge: the effects of weather, not only on the coating but on the substrate to which it is applied; the roof itself.

Regardless of the composition of the roof it will react to extremes in temperatures: expanding in heat and contracting in cold. There is nothing the applied membrane can do to prevent this.

Where a membrane or felt has been cut into pre-ordained sizes and shapes and then “welded” together to form one discrete seal it is then subject to the climate-caused movement in the very structure to which it has been applied. All pre-formed sheeting which comprises the gulley or duct will begin to “stretch” or “squeeze” the sealant applied to it, eventually causing “welded” seams to burst and crack, and fissures to appear in cured rigid liquid membranes.

FlexiStop, on the other hand, never goes rigid, but remains completely supple and flexible in temperatures as high as +2000 Celsius and as low as -600 Celsius.

(The most extreme temperatures experienced in Western Europe would never reach these values: in Athens, temperatures of +480 Celsius were recorded on July 10th, 1977; in Kittala, Lapland, temperatures of -51.50 Celsius were recorded on January 28th, 1999.

The highest temperature ever recorded in Ireland was 33.30 Celsius, in Kilkenny Castle, in 1887; the lowest was -19.10 Celsius in Markree Castle, Sligo, in 1881.)

FlexiStop will move and “flow” with the building and substrate it has been applied to, regardless of weather conditions, and the manufacturer guarantees that it will do so for a minimum of 35 years.

Consequently, once applied correctly to a gulley, duct, or any kind of roofing situation it will cure in approximately four hours, remaining leak proof and fully vapour permeable (10 times more so than most hi-tech preformed membranes and 100 times more so than bitumen based sealants). None of the problems associated with temperature enforced movements will affect is performance.

In the photographs shown, the “bellows” connecting two railway carriages, made of a very heavy fabric, has been torn. Rather than replacing it, a time-consuming difficult process that often takes the carriage out of commission for some time, the material has been repaired using a coat of FlexiStop applied below and on top of a non-woven polyester fleece. The entire job takes about four hours and the carriage is back in service.

This repair will now allow the bellows to expand and contract, like an enormous accordion, many thousands of times on each and every train journey. FlexiStop remains supple and flexible throughout!

There are many advantages of liquid coating systems over traditional solutions for roof refurbishment because it forms a permanent, seamless membrane which is ideal for long term waterproofing of awkward roof details such as pipe penetrations and gutters.

FlexiStop is ideal for use in complicated roof profiles; it can be applied to flat, sloped or vertical surfaces and, when cured, forms a single seamless membrane, and is suitable for tanking, roofing and tank bunding. This is particularly useful when coating a roof surface that may have rooflights, airvents, parapets or other vertical upstands. Instead of a preformed membrane being cut and "tailored" to fit these upstands, and then being heat-welded or mechanically fixed into place, FlexiStop is simply brushed or rolled onto the surface like a thick oil paint

In addition, because it will bond to a great many substrates it is suitable for use in numerous applications without having to remove and dispose of the existing roof covering.

As well as the reduction in the maintenance which is required, it also reduces the refurbishment costs and the environmental issues associated with waste disposal.

  If you have any questions, just call our team on 0800 949 9019.