System or battery garages have very nearly flat roofs, usually only about two degrees. They are naturals for allowing moss and vegetation to take hold as shown below. The original asbestos material and the replacement fibre cement sheets are a suitable growth base for such organic material and the sheets become porous, break up and leak. Plastic coated steel does not provide a surface for such vegetation to attempt to root and therefore does not become porous and remains waterproof.
Rain has to be allowed to drain away rapidly and without the obstruction of leaves and blown debris filling gutters and downpipes. Gutters often need cleaning out depending on the location, under trees for instance. The gutters in molded lintel/gutters are small and easily block causing water to rise over the gutter-to-post joint and into the garage. This water then runs over the spring/lever mechanism of the door causing it to rust and eventually fail.
With the System 8FX the moulded concrete lintel/gutters are replaced with powder coated aluminium extrusions which will never rot, spall, rust or crack. The concrete posts which contain the downpipes are replaced by square section aluminium extrusions which are also powder coated. The aluminium downpipe channel cross section has an area of 5250sqmm whereas the downpipe contained inside the concrete post is only 2043sqmm, or roughly two and a half times the capacity. So the aluminium post/downpipes are less likely to block and even if it did then frozen water in the downpipe will not cause the pipe to crack or split which happens with the original concrete versions.