Building Control Guidance on Retro-fitting Solar Panels

[Guest123]

Found this on the LABC website and thought it would be relevant here.

 

[bigbob1]

Here's a bit of guidance for anyone that has used the Klickfit (pull over tile and batton roof anchors) mounting system.

Once the local building authority knows you have used this system they will make you take it down at your expense!! as it goes against bre guidance and dti guidance and building control guidance (part A)

"you cannot fix a roof anchor to a batton in any way shape or form, you must fix to a rafter which is capable of taking estimated loads"

Spread 4 rows of rails across diffrent rafters to spread out load balance.

I think Klickfit have sold alot of this stuff in the UK and alot of companies thought it would save them time and money ooops!

 

[Worcester]

@Bigbob1

Before you make a post like this please get your facts correct. In fact your post is actually potentially libellous.

Most people here know my background and qualifications, if you don't, then I suggest you do your research and dig through some of my posts BEFORE you respond.

1) I presume that you are actually referring to the ClickFit system.
2) If you are then it has been fully tested at BRE - I have a copy of the full and comprehensive test reports.
3) You need to understand how uplift pressures and dead load forces work on roofs, most of the Building Regs people don't.
4) The document referred to above has been well discussed on this forum and has already been changed due to pressure from folks here.
5) The document is guidance only from a non-authorative body.

 

[bigbob1]

I'm only relaying what Graham Evans Inspections Manager South has said to us and what Building Control for Essex County Council have said to us so no need to get your knickers all twisted up.

 

[bigbob1]

143 mph and all the click fit clamps bend totally out of shape, and the bottom corner comes off a panel, and that was just testing the up lift on the panels with clamps at 400mm centers!! with suckers attached that can't re-create the back and forth blow of the wind!! lets hope we don't have many big storms for your sake, luckily i can read that report and understand it. Maybe thats why in the guide's for all this they say you must not attach to a batton but the rafter that is geared up for load baring wieghts. Good job i have a guy with a 7 year carpentry and joinery apprentaship his hnd's and hnc's and advanced skills certificates in building roofs and he can say weather the roof will blow off!! beacause the click fit system will blow off if the roof isn't battoned properly. 2 panels where tested imagine if it was 16, 2 x 8 rows, 600mm rafters so there are 3m long battons all nailed once every 600mm??? thats not many nails!! JUST A CHEAP AND TACKY WAY TO SAVE £300 AND CUT DOWN ON 1 MINUTE A BRACKET!! Get Cleaner Air Solutions to do that rig in the BRE tunnel and see what happens when they stick it up to force 7 winds. Worcester you do whatever you want with your work mate but i will carry on doing it properly thank you.

 

[Worcester]

Not getting my knickers in a twist, as you are obviusly knowledgable in this area, and with an experienced team.

Perhaps you would care to share what you do that ensures that you comply with Eurocode 5?

Appreciate your advice, so that we can all learn.

 

[bigbob1]

No Probs

Forget about Eurocode 5 untill you've looked at Eurocode 1 EN1994-1-4: 2005 http://www.thomastelford.com/books/...ide to EN1991-1-4 Eurocode 1 wind actions.pdf

Also look at this program it can help greatly WOODexpress - Design of Timber structures according to eurocode 5 this is Eurocode 5 software.

I have talked to alot of people about this as saving a bit of money on mounting systems is a no brainer but........

If you can imagine how easy it is to pull a nail with a hammer and you have roof anchors attached to a batton that can twist backwards slightly then you attach a wing to the anchors, when the right gust of wind occurs it will act like a hammer pulling the nail.
over a period of time constant moving on the anchors will loosen nails, so not 1 gust but repeated gusts can loosen and make that 1 gust take the batton off, on modern houses using a plas gun to put battons on can increase the risk even more as these nails somtimes go right into the batton. Particularly on properties in open areas surronded by fields for instance and the more you go above sea level.

It's just been expressed to me to avoid this mounting system like the plague, after looking into it i will.

Bob

 

[Worcester]

@bigbob1 We all have our feelings on this, so I'll respect yours on this.

So that stillleaves the question: How are you / what are you doing to comply with Eurocode 5 Table 8.6?
This is a major problem on 35 mm trusses.

What's your magic answer?

I'd appreciate your help on it.

 

[bigbob1]

hi!!

My magic answer is........... fixing to the top of a rafter has nothing to do with axially loaded screws!! so table 8.6 of eurocode 5 has absolutely nothing to do with mounting a roof anchor!!. As your not loading the screw in tension, or creating a shear force on a structural joint.

Don't just take my word for it as i'm sure you won't. Phone up a chartered structural engineer like i have!

If you where placing the roof anchor inside the roof underneath the rafter then this would be axiall loading!

Once the engineer has e-mailed me the information you will need, i'll link it here.

Untill then you have a really good weekend proffessor.

 

[bigbob1]

Refer to BS 5268 part 2:2002 Appendix G for your screw type's and lengths.



Cheers

 

[Worcester]

If you where placing the roof anchor inside the roof underneath the rafter then this would be axiall loading!

Once the engineer has e-mailed me the information you will need, i'll link it here.

Thanks BigBob1, I'd really like to see that email.

 

[bigbob1]

What you have linked there is what was said on the phone.
this is the information he sent me >>Refer to BS 5268 part 2:2002 Appendix G for your screw type's and lengths.

and this is the email he sent saying the thickness of an acceptable screw>> to be put in to a pre drilled hole.

Hi Robert.

As long as the diameter doesn’texceed (3.8mm) say 4mm that will be fine.

Chris

Ken RushAssociates
Bowman House
191 South Street
Braintree
Essex
CM7 3QB
tel: 01376 326789
fax: 01376 342711
Technical email: [email protected]
Adminemail: [email protected]


for fitting to the top of a 38mm rafter as everyone i've spoken to says it's 38mm not 35mm, no more than shaft thickness of 4mm for the screw. So 3mm pilot hole 4mm screw shaft.

Hope this resolves issue, contact him if you want he's a nice guy, and will explain axiall loading to you if you really want to know, as i think you where a bit confused as to what it was/is.

 

[SRE]

Hope this resolves issue, contact him if you want he's a nice guy, and will explain axiall loading to you if you really want to know, as i think you where a bit confused as to what it was/is.

I think you'll find you've underestimated Worcester, I suggest you review his posts

 

[Worcester]

That's the exact problem Bigbob!, can you show us a picture of one that you've fitted with 4mm screws then please.

 

[bigbob1]

SRE he wouldn't be on here if he had done 7 years at college to become a structural engineer would he?

I suggest you check out SIG fixings, you can get a 4mm shafted hex head zinc coated wood screw.

cheers

 

[bigbob1]

i'll take a load of pictures for you to show you how to fix an anchor with a 4mm bolt to a rafter not a problem.

I suggest you use a person that is competent at being able to evaluate a structure and give you proffesional advice on how to go about doing your work on that structure. It seems you don't.

I can't see what the problem is with finding the correct fixing to do the job i don't struggle with that??

If a chartered structural engineer, that you can contact and talk to about this (please do!) says that a 4mm screw is okay for a 38mm rafter then what is the problem??

I think your just a bit annoyed that you've been pulled for even thinking about using the crap clickfit system and are obviously trying to move away from that fact, by quoting stuff from charts (EC5 table 8.6) that has absolutely nothing to do with this etc etc axially loaded screws etc etc.

I have never claimed to know everything about this but some people appear to think they do. I have not got a problem asking the right people the right questions to get the correct answer.

So it brings me to this, "How do you fix to a 38mm rafter???" OH YEAH you use clickfit!!!!

Some people eh!!

 

[SRE]

SRE he wouldn't be on here if he had done 7 years at college to become a structural engineer would he?

I suggest you check out SIG fixings, you can get a 4mm shafted hex head zinc coated wood screw.

cheers

I'm not sure I get your point about going to college for 7 years meaning he shouldn't be here??? I've been to college for a similar length of time does that mean I shouldn't be here either? I'm not keen on Clickfit but don't feel the need to critical of either perspectives, it's a personal choice that you each have to be happy in your own mind is suitable for your installs. No need to attempt to bludgeon anyone into submission with superior knowledge or be disrespectful of other points of view.

I'm guessing that it's been a long week for everyone

 

[Worcester]

I'll take a load of pictures for you to show you how to fix an anchor with a 4mm bolt to a rafter not a problem.

Many thanks Bigbob1 would really appreciate that, it's always good to learn from experienced people, - What anchor / fixing system are you using with those screws?

 

[bigbob1]

Schletter mounting system

You'll have to talk to SIG fixings and ask them to get hold of those bolts, i just get 500 a time bout £25. They do a sealing washer as well that will fill any gap up in the roof anchor hole when a washer comes down on top so there is no movement in the bracket once fixed, and these are designed for roofing applications so have a long life and don't perish. they do a fixing that you use a ratchet on and also one that can be done up with a battery drill.

They also do a self drilling fixing for wood application but i think this is a no no.

One i'm starting on the 5th September has 38mm rafters.

 

[Worcester]

Schletter mounting system
One i'm starting on the 5th September has 38mm rafters.

Would be great to see the photo's on that, thanks

 

[Fitstart]

So should I be worried that a company is coming to fit panels to my roof next week and they are going to use ClickFit?

 

[SRE]

It wouldn't be my choice, but I think you can be reassured that if Worcester is using it - it meets all necessary requirements. He's a chartered engineer and will have reviewed all relevant issues in microscopic detail. Building Control officers rarely have an engineering background and tend to get the wrong end of the stick regularly. They have just had to repay numerous Building Control fees to customers as a result of a mistake made (in good faith) by BC officers.

 

[Fitstart]

Thanks for the reply, that has eased my concerns a little. I am in a fairly exposed rural spot in Scotland however. The installer assures me that it will be fine. House is mid eighties timber frame bungalow.

 

[SRE]

As long as you've had a structural survey and the surveyor has said it's fine you'll be ok. Make sure the information from the structural engineer is included in your handover pack when you get it and if you haven't had a structural survey - get another installer

 

[Fitstart]

No structural survey. Again the installer said it was not required.
Starting to get worried.

 

[SRE]

No structural survey. Again the installer said it was not required.
Starting to get worried.

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!!

 

[Fitstart]

I'll contact a structural surveyor tomorrow! - Install is supposed to be on Tuesday.

 

[SRE]

I'll contact a structural surveyor tomorrow! - Install is supposed to be on Tuesday.

Should be the installer that does it and pays for it. They will get it much cheaper than you will - if you're in a particularly windy area make sure they fit extra hooks on the top and bottom rows. We only ever have top and bottom row hooks @ 800mm and 1200mm in the middle.

 

[Fitstart]

Thanks I will also contact the installer and inform him that I want this survey done and we can negotiate how the fee is paid. I presume the VAT can be reduced to 5% if he organises it.

 

[SRE]

Yes it should be all part of your install costs.

 

[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.

 

[SRE]

Thanks for insulting my integrity - I'll try not to take offence and assume that it's because you've got your knickers in a knot about something that you haven't done yourself. How on earth do you know what I believe? Most intelligent people take a range of views and opinions and make a decision themselves.

Have you read the instructions and consulted a structural engineer about the roof kits? I have and my guy is working through it but he's busy and I haven't time to chase it at the minute - if someone else is contributing to the legwork then I appreciate it, it diesn't mean that I will take as gospel what it says. I once took a Strathclyde University study to pieces in a very short period of time - not particularly Strathclyde's problem but they had been given a poor remit for their work and the result reflected that not the efficacy of the product they were evaluating.

Correct me if I'm wrong but pv installers, wholesalers, manufacturers are all private sector - if some of them chose to get together as a result of some structural concerns and come up with something that will make installations safer - what's the problem - that you haven't done it or thought about it? My point about Apple is that if they had consulted with others while developing it how would they have protected their IP - surely that's all Worcester et al are doing? Who's to say that you can't do a better job - will you consult with others and let them into your little secret? I think not. It's business, plain and simple.

I have shared information many times for it appear as someone else's brain wave - it's infuriating - I don't blame Worcester for keeping it quiet, I'd suggest that it's pretty good commercial acumen.

 

[solarsavings]

SRE, firstly I don't see that I've insulted you in anyway whatsoever. Perhaps my saying you are ready to accept what worcester says has left you feeling insulted but as I don't recall you ever challenging what he says I have to conclude you accept it. As for what you believe, I based that on your many responses to his various posts. If I'm wrong it waasn't an insult.

I have read the installation instructions on all of the mounting systems we use including the K2 ;-) and strangely always read the manufacturers instructions for the other equipment as well. I don't believe I need to use an SE to check the roof structure or clacs as I'm reasonably certain that I have the ability and experience to do both myself.

I have no problem with anyone "getting together" as you put it, providing it's in the open and or it doesn't effect me. But as this getting together was put to us as being "secret" and that it involves those that can impose their ideas on us as installers and suppliers I do have a problem. I want to know how that can be right and proper. If there is to be a new design standard do you think it right only a chosen few should be aware of it? do you think it right that those few should have the jump on others because they're in the know. If true, it stinks.

As for sharing your knowledge and experience, I thought you were both happy to do so.................or least that's how it seems to me.

 

[Worcester]

@solarsavings

The information I posted about is available to anyone in the industry if they care to put the time and effort into building and establishing the relationships that I have. This is not 'secret' however people aren't shouting about it, and like any industry some companies will develop an advantage because of the time they invest in the right places.

The report we paid for ourselves, it's independant. It's confidential, because some of it is highly contentious. You could do the same yourself.

What we are doing is not 'secret', it's what is going on in any industry as new standards are developed.

It's our own time and money that's going in to develop new mounting system - I'm not stopping you doing that.

As for sharing information, I'd have thought that after seeing this : see photos : you'ld be glad that some standards for mounting systems that everyone has to comply with are being developed

From a visit to a site today, from someone who was proud of their work, and wanted to show it off to see if he could join one of my teams, apparently they've done at least 20 houses this way. - So should I tell the house owner or not:


So should I give any advice to the guy as he is MCS certified, and believes he's doing a good job?

Or just say, "it's not to my method or standard sorry mate."

 

[solarsavings]

Worcester thank you for now clarifying your previous post. If you take the time to re-read your earlier post you may see it the way I did.

I have no problem with any company designing a better (or worse) mounting system as it's difficult finding one that has 'everything' my problem is if, as your post led me to believe, it's being done in secret with our lords and masters. The fact that you have doing it with your own time and with your own money is to be commended and maybe it might be the 'one' we're all looking for.



As for changing standards, again I have no problem with it and think perhaps one system that may suffer is the click system
( I wont cry about that). But changing standards should be done in consultation with the industry not without it.

Our short lived experienced roofers did this on their first job for us and said it was due to the mounting system. They were finished and on their way home by 11am.



We found this pile of broken tile under the modules.

 

[SolarCity]

Good God.... that is truly horrific. And this is the one they showed you?

Hopefully they haven't done many slate ones....