H&V News recently reported that British Gas is investigating solar installations at more than 100 schools and businesses following a series of “mystery fires”.
In the same article, British Photovoltaic Association chairman Reza Shaybani suggested that it was possibly poor installation or use of wrongly specified, incorrect or faulty equipment that could be the cause, and this is a view that I strongly support.
As the managing director of a company that specialises in manufacturing and supplying specialist flashings to the roofing and solar industry, I take an interest in looking at how installations have been flashed as I travel around the country.
While I see many jobs that follow best practice, I also see more than I would like where the method used to carry pipes and cables through the roof is, quite frankly, poor. Cables are not adequately protected when they are simply pushed under tiles or slates, or placed in a groove cut out of the tile.
Not only are these installations more likely to afford poor waterproofing, the risk of electrical danger is high if cables are allowed to become frayed or compressed.
Responsibility for fixing solar panels often falls between several trades: roofers, electricians and plumbers. Plumbers and electricians have little experience of fixing things to roofs and roofers have little experience of working with pipes, cables and penetrations.
The best way around this confusion is to use specialist flashings that have been designed for use with solar panels.
Well worth the cost
Specially designed flashings are easy and quick to fit, and take away all the hassle involved in fashioning DIY solutions specific to each job. Of course, keeping job costs to a minimum is important, but failing to properly weatherproof roof penetrations and adequately protect PV cables from damage could prove to be a false economy.
Should the MCS inspection fail the certificate holder is liable to carry the additional costs of re-inspection, which at current daily rates would be an eye-watering minimum of £600 plus VAT – not to mention the word of mouth damage a customer complaint could do to a business.
A typical domestic solar thermal installation requires two pipe flashings at a total cost of no more than £60. A single multi-cable flashing at £30 or less will protect and weatherproof all the cables on a typical PV installation.
Flashing products are seldom included in the manufacturers’ installation kits, but it is a crucial part of the process that is often overlooked.
It would be logical to assume that you have bought everything you need to the site, but in the majority of cases flashings are omitted on cost grounds.
Make flashing a part of each job
All manufacturers want to see their products fitted correctly to deliver optimum performance to the end user. But while the use of flashings is included in training seminars, most of the installation guidelines contained in manufacturers’ kits do not cover their recommended ways to seal the penetrations.
In an ideal world, flashing products would always be included as part of installation kits or merchandised alongside.
Companies are working closely with merchants and suppliers to try to achieve this in order to drive up consumer confidence around solar and to improve installation standards.
But in the meantime, if in doubt consult with the technical department of your merchant or a quality flashing manufacturer should you need advice on flashing solar installations.
David Jones is managing director at DEKS Europe