We're awaiting the replacement of a fallen roof tile, a problem that has exposed the wear and tear of the entire mortar verge at the edge of the gabled tiling. The roofer has suggested plastic dry verge roofing. Here is what the plastic proponents
have to say about it.
"If you have a gable roof and live in an older house, the chances are that you have ‘wet verge’ roofing. The ‘verge’ refers to the outer ends of your roof above the gable end (the wall above which two verges meet). Traditionally, these areas at the edge of your roof are fixed with mortar in order to prevent water ingress and pests such as birds nesting in your roof. Roofs rendered with mortar for these purposes are what we refer to as ‘wet verges’.
There’s no doubt that mortar does the job it’s built for; it stops pests getting into your roof and will stop water leaking through too. The real problem with mortar lies in its durability. Mortar naturally deteriorates over time due to weathering caused by facing the elements and the natural movement within a building structure, which can dislodge the mortar. This leads to cracks in the mortar which can lead to the problems it’s meant to prevent. It can also leave your roofline looking quite unsightly.
Mortar requires regular maintenance to keep functioning, such as repointing. Unfortunately, this isn’t the sort of task you’re able to carry out in an hour on a Sunday afternoon – it often requires scaffolding to be erected which can be costly. There is no way to stop the deterioration of mortar, which means the only guarantee you get from it is maintenance costs further down the line.
Thankfully, mortar isn't the only option for preventing water ingress and pests in your roofing. ‘Dry fixing’ is an increasingly popular roofing option which allows for the weather and pest-proofing of your roof without the need for mortar.
Dry verge roofing makes use of interlocking caps that fit over the edge of your roof tiles, and offers an effective and, more importantly, durable alternative to wet verges.
Dry verge caps are usually made of plastic, which in itself offers some distinct advantages. The most obvious advantage is plastic’s durability; plastic verge caps should last you at least 10 years and require a fraction (if any) of the maintenance associated with mortar. Essentially, you won’t need to worry about your roof leaking in or any pesky birds nesting in your roof!
Plastic’s durability also means that your roof will look better for longer. It’s a bit of a myth in the building trade that traditional materials such as mortar look better on older houses and that plastic can be a bit ‘impersonal’ and ‘cold’. This isn’t the case; plastic offers a clean finish that is guaranteed to last. With more and more homes adopting dry verge systems, your roofline won’t stick out like a sore thumb either.
It goes without saying that dry verge roofing offers all the roofline protection required just as, if not more, effectively than wet verges. Opting for dry verge caps also offers some distinct advantages regarding ventilation. They are fitted so that some air is allowed to enter, thus providing the natural ventilation a roofline requires to not get damaged by the elements.
If your mortar is starting to look a bit shabby, don’t waste your money on expensive repointing that will only last for a few years – look at investing in dry verges instead."
How durable is uPVC?
"Un-plasticized Polyvinyl Chloride is also the most durable of the materials available. Aluminium can pick up rust whereas uPVC is strong, tough and resilient. It is highly unlikely uPVC will need to be changed and some companies even offer up to 10 year guarantees on uPVC double glazing."
