Building Control Guidance on Retro-fitting Solar Panels

[solarsavings]

Every job without exception should have a structural survey - it doesn't cost much in comparison with your overall spend. Insist on it or change your installer .... very shoddy approach not to have one done - high winds ... who will you fall back on if the roof can't cope with the windload?

We've just recently done a job in eactly the same situation as you - our structural guy rejected the roof because it was showing signs of splaying. One beam installation later (about £350 and a lot of swearing) and the customer had a roof suitable for the installation of solar panels. If he's gone with the other installers he'd invited round - all nationals - not one of them did any structural calcs - could have been a solar sandwich!!

Splaying? not heard of that before in relation to a roof structure. What does it mean and how did a beam fix it, I'd be interested in the answer.

 

[SRE]

Well with the caveat that I'm not a structural engineer, from what I understand, houses built in the 50's and 60's have roofs that are at the edge of their tolerance and potentially the extra weight could essentially make the roof cave in. In this instance the roof was at the edge of it's tolerance and by putting the beam in the full length of the building it tied everything into the structure - but as I said - I'm no structural engineer, that's we bring the pro's and their professional liability insurance in.

 

[solarsavings]

I can't picture how a roof would splay so perhaps that's why I cant see how a beam would prevent/cure it. Are we talking timber beam? Where and how was the beam fixed in place.

 

[SRE]

Sorry not much help - it was a metal beam and I think it was anchored in the walls but tbh I could be talking a load of rubbish cos I didn't see it when it was done (I don't do the installs my partner does). Our structural engineer did the drawings and calcs and the customer followed what he's instructed and had it passed by BC.

 

[solarsavings]

OK thanks anyway.

 

[MorganPVI]

So what ratio of installs requires remedial action? 1 in 25?

 

[SRE]

Seems to depend on where you are in the country - about 10% of ours have needed work, but I've seen a structural engineer on this froum saying that 50% were failing. I think he was getting a bit carried away!!

 

[t4sltd]

I'm not a structural engineer but work with qualified roofers. The problems I would worry about are the roof collapsing under additional weight / down-force due to the roof slipping off the wall plates. I would never fix to a batten and I'm pretty sure all of my roofing friends would advise against it.

 

[Worcester]

Well I am a Chartered Civil and Structural Engineer, and it's not friends advice I take, it's professionals.

I have a 20 page confidential report that has been prepared on the problems associated with the current mounting systems, and I also know that there is a new MCS certification being drawn up that all mounting systems will have to comply to with and be certified before they can be used.

As a company we are developing mounting and fixing systems, that are fully compliant with the new standards, and are working with a number of the existing providers to help them develop compliant systems, you'd be quite amazed at what can actually be achieved, however until the spring, my lips are sealed!

 

[SRE]

So until Spring when your lips become unsprung - what's the best course of action for us mere mortals?????

 

[Worcester]

@SRE, You know me well enough

It's about doing the right thing, and following best practices.

One of the biggest problems we have is that very few of the mounting systems come with proper comprehensive installation instructions.

When did you last get installtion instructions with a mounting system that you bought?

In other sectors, even roof mounted solar thermal, comprehensive step by step instructions are provided.

Yet the mounting systems we import direct from Germany regularly come with such detailed instructions, and from those it's aboslutley clear that in some instances, they shouldn't be used!!.

So to answer your question. Do your best, follow what codes you know, and most importantly, check with your local building control department (sorry about that one ) that they are happy with what you're doing. Even better, get them to profer a solution, (they'll like the opportunity to do that it makes them feel good!) don't throw a wobbler at their initial completely unworkable sugestions, bring them round to thinking that your solution was their idea and then confirm the solution in writing, by email at least.

Sorry mate, back to talking to them's as took all your money off you!

 

[solarsavings]

We were recently emailed details of a roof hook that doesn't require screwing to the rafter or hanging off a tile and batten like the clik system. Hopefully the manufacturer is a member of the "chosen" few who claim/have influence over what we do.

 

[solarsavings]

I have a 20 page confidential report that has been prepared on the problems associated with the current mounting systems, and I also know that there is a new MCS certification being drawn up that all mounting systems will have to comply to with and be certified before they can be used.

As a company we are developing mounting and fixing systems, that are fully compliant with the new standards, and are working with a number of the existing providers to help them develop compliant systems, you'd be quite amazed at what can actually be achieved, however until the spring, my lips are sealed!

If what you say is true then the whole system is a bloody disgrace. Why should a chosen few have early access to the "new" standards that will allow them to develop a system that complies. It stinks of corruption, and I for one intend making noise about it as of today.

 

[SRE]

If what you say is true then the whole system is a bloody disgrace. Why should a chosen few have early access to the "new" standards that will allow them to develop a system that complies. It stinks of corruption, and I for one intend making noise about it as of today.

There's nothing to stop you doing what Worcester is doing - other than what stops most of us - time and money.

That's the way of the World, would you have expected Apple to have opened up consultation to their competitors before they launched the Ipad or Ipod. I could spend all of my time lobbying trade bodies and government but I wouldn't have a business I don't have the time and if I made the time I wouldn't have the money. I chose not to expand although we very easily could and accept that the result of that is that I'm not as active in the industry as I'd like to be. BUT I do know where to go for answers and Worcester, TedM etc are usually happy to oblige.

Personally I appreciate the feedback that Worcester provides - I used to do that in my previous work and the installers that we cascaded info to always appreciated it. Everyone is richer for the contributions on this Forum.

 

[solarsavings]

It's got nothing to do with worcester and everything to do with "secret collusion" to change the type of mounting system we "can" use or how we use it. How you're able to link Apple to this beyond me. Apple to best of my knowledge is a private company, it has no impact on the way I work in any way. Do you honestly believe something so significant as the mounting systems we use should be decided by those with a vested interest?

I know that you are always happy to accept what you are told by worcester and that's fine by me. But if worcester is doing something "secret" that can have an effect on me and my business, then I for one am extremely unhappy about it.

I have have spoken to the MD's of two major players in teh UK this morning and the employees of a couple of others asking them if they are aware of this secret consultation going on as they are suppliers of mounting systems in the UK. Not one of them has heard anything about it. I am waiting to hear back from my registration body if they have heard anything either.