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