Over recent months we have been highlighting the fact that fibreglass or GRP (FRP) can be a realistic cost effective alternative to lead, particularly where metal is subject to the increasing risk of theft. Unfortunately, as we know from the news reports, theft for some buildings can be a regular event and expensive to deter.

In the case of our GRP Valley Trough range, we have been making the point for almost thirty years that GRP has no value to a would be thief;  in fact since the very first time when we started manufacturing these products specifically to simulate lead and other metals such as zinc.

However, we have never argued that there is not a place for the use of lead within a roof construction and indeed our Valley Trough range  can be used in conjunction with lead where required.

Let’s take as an example our Dry Fix Valley range. This product, which is patented by us and therefore unique to us, was developed to replace the need for the use of mortar during the roofing process,  but it was also designed to  utilise a  traditional lead saddle to provide the weathering protection at the head of a valley.

Why?  Because lead is ideal, it’s standard practice for the roofer, it is easily formed to meet the profile of the Dry Valley and it will provide a very long service life without the need for maintenance – a well proven material and is this application with little risk of theft due to the discreet use and therefore minimum visibility!

There are alternatives of course, some being typically based around a preformed “plastic” moulding but there are inherent disadvantages with that type of material. Expansion and contractions rates, exposure to sunlight and temperature extremes may well weaken the material over time; this type of product has been tried in the past but they tend not to succeed in practice, and are also unlikely to have the same long service life expectancy as GRP or lead. Being pre-formed, they often do not have the versatility to accommodate a wide range of roof pitches or differences in roof pitch and may not be best suited to the detailing required.

We recommend using lead in conjunction with GRP valleys as none of these disadvantages apply!

Hambleside Danelaw, the UK market leader for GRP mortarless flashing products, is urging builders to follow a new NHBC recommendation that they should seriously consider opting for dry systems on pitched roofs to reduce their risk of incurring remedial works due to mortar failure.

The NHBC has just reported that 60% of claims handled in 2010 related to pitch roofs and half of these claims were due to mortar issues. The Council‟s latest Technical Extraguidelines ask, “When was the last time you considered the latest dry systems available?”

Availability is easily found within one of the most comprehensive dry roof ranges offered by a British manufacturer. The range includes Dry Fix valley troughs, ridge and hip systems, soakers, verges and bonding gutters. Some of these Danelaw products are listed in the WRAP procurement guide because they contain up to 50% recyclable content.

Scotland leads the way

The NHBC says that almost all of its insured sites in Scotland are now being built with dry systems for ridges, verges and hips. Claims figures appear to support this move to dry systems, with Scotland experiencing a smaller proportion of pitched roof claims per property covered.

Since the start of 2011, Project Managers for three local authorities in Scotland and the Glasgow Housing Association have specified Hambleside Danelaw‟s Dry Fix Bonding Gutters and HD TV15 Tile Vents.

Dry verges reduce claims

Verges are also reported by the NHBC to be a common feature of pitched roof claims and can require complicated and expensive scaffold access to facilitate repairs. Hambleside Danelaw supplies dry verges in either a continuous verge or interlocking dry verge option, providing permanent protection to the roof edge.

Chris Avery, Hambleside Danelaw’s managing director, comments:

 “Repairs directly undertaken by builders add to the £11m bill which the NHBC faces for pitch roof claims, so it really makes sense for specifiers and contractors to look at the Dry Fix option. And if you choose Hambleside Danelaw, you are buying products designed and made in Britain.”