Jimmy Hall
Everybody’s a Roofer…
During my forty plus years as a slater and tiler, I often smile at the fact that everybody in the building industry whatever their trade can “do a bit of roofing”. You see vans that have signs for ‘Joinery and Roofing’, ‘Bricklaying and Roofing’, ‘Plastering and Roofing’. I think the only trade I can say I have seen that does not combine their trade is an Electrician.
With the introduction of the solar industry it now seems that electricians can “do a bit of roofing”.
I became aware of the problem of fixing solar to roofs in March 2011 after demonstrating my slate repair solution at the Ecobuild show. The solar industry had never crossed my mind until I was informed by a number of installers, architects and homeowners at the show, about the problem of fixing solar to slate roofs. My immediate thought was that they must be using roofers to fix the panel brackets to the roof, however having seen some of the brackets on the market, I struggled to see, not just how they work, but more importantly how the integrity of the roof could possibly remain after they had been installed. This is with extensive roofing experience. How can a non-roofer be expected to do a proper job, involving complex roof repairs?
I must admit, I have really struggled with the integrity of this type of work. If I carried out electrical work for gain, I would be in trouble with the authorities.
All industry efforts to simplify fixing to slate or tiled roofs to keep costs down are not adequate methods. There is no simple way of doing a skilled job. Despite MCS stating that drilling through the slates is not considered a durable weathertight solution, many MCS accredited installation companies openly advocate drilling (type ‘solar panel slate roofs’ into Youtube). This year, the MCS012 standard, goes further to eradicate this practice, however MCS have confirmed that the policing of this is likely to rely on whistleblowers.
If I was a home owner I would be making sure this standard was enforced and at the very least I would use an installer who did the job in the correct way.
I speak to experienced roofers who have to make it up as they go along due to the unsuitability of brackets and the assumption that it’s an easy job. This is a real problem, confirmed by stories of leaking roofs, ruined roofs and even legal proceedings.
The article in the Solar Business focus magazine by Dr Kevin Ley, Technical Manager from Redland, highlights that the problems with tiles leads to broken tiles, in an attempt to get by without using any type of flashing for ‘economic’ reasons.
“We just notch the tile above the bracket”. I hear those words spoken with authority by people who in my opinion do not know what they are doing.
I recently, locally saw a new build installation on Cambrian tiles where I know the roofer. He happens to be a very good roofer. The installation looked very untidy and patchy; the brackets were sat on the tiles and the lead flashing looked like a “make do and mend”. If I had been given the same materials and brackets as this roofer I would have done exactly the same. My point being that the roofer/installer needs to be given the correct materials for the job so as not to have to make do.
Manufacturers have designed brackets to keep them low, believing this will make for easier flashing. This makes the roof material load bearing as the bracket/rails/panels are sitting on the slates or tiles.
With slates, by using a bracket with an elbow of at least 30mm and a hooded flashing, the slate flashing problem is completely eliminated. Ask any roofer and he will tell you how easy it is to break a slate, especially imported slates. No manufacturer I have asked can tell me how a ‘flat’ bracket designed for slates, works. I can only assume they are designed for drilling.
Despite MCS012 advocating notching, in my opinion it is bad practice as it weakens the roofing material. To use a bracket on a tiled roof of flat, profile or roll tiles, it is necessary to use a hooded flashing instead of notching the tile above. The brackets manufactured for tiles, even those manufactured for specific tiles rely on knowing the thickness of the batten, and the tile, which is not always exactly the same. A ‘standard’ bracket will not always work, because of these differences. It therefore makes sense for the bracket to be manufactured to clear the tiles, thereby avoiding making them load bearing. By using a hooded flashing and then cutting the tile to finish round the hood, this allows movement/flex inside the hood.
Brackets for plain tiles, even those purporting to be designed specifically for them, don’t take into account the fact that the distance from the top of the rafter to the face of the tiles is less at the top of the roof than at the bottom. Where it might be possible to fix at the top, the bracket will not clear the tiles at the bottom. Also they usually don’t fit between the battens which are gauged at 100mm centres, leaving a gap between of 50mm to 65mm.
By following the principle of using a bracket which stands off the tile/slate and using a hooded flashing, the installation of a solar panel bracket could be made faster and easier for the installer to understand, but most importantly for the homeowner there can then be no issue with the integrity of the roof after installation.
It surely makes sense to have the brackets above/proud of the roofing material and a purpose made hood type flashing to allow independent movement of the bracket, rather than trying to make a sturdier bracket to eliminate the movement (WIND). With tiles this is because when the tile above is “notched” (eating into the tile) a heavier piece of steel means more notching if the installer can be bothered. This is not possible with Redland Cambrian or Marley Edgemere and certain others, because of their thickness.
You have to have worked on as many roofs as I have in the last forty years to have seen every possible problem. This method as described above leaves no possibility of failure or ongoing issues with weather tightness.
So, if you see a van with “Solar bracket designer and Roofing”, don’t let them on your roof.
What started out as pottering for me has now turned into research; more than many large companies seem to have carried out.
It shows the lack of roofing knowledge of installers when they turn up at a job with no spare slates or tiles. This in turn becomes a problem, as not having the equipment on hand, leads to make do repairs, and in turn causes the installer to think that it is not worth the trouble. We have spoken to so many installers who won’t touch slate roofs.
So, in summary, if the standard method of install was to cut the roofing material around a hooded flashing, then even the non-experienced roofer/installer would know how to install a bracket and flash around it with confidence.
They can sleep at night knowing they had completed a failsafe install, and the customer whose property it was, could do likewise.
I designed the SolarFlash® system to enable all installers to do it right. The system is compliant with MCS012 requirements. See demonstrations at www.geniusroofsolutions.com