Mounting solution for corrugated cement roof

[SolarCity]

We've just been to look at a large warehouse job (possibly 40-50kW)that we're very keen on winning. Unfortunately, the roof is made up of corrugated cement sheets and we haven't had to tackle this kind of thing before. We were thinking along the lines of using hangar bolts but weren't sure if these were designed to screw into timber rather than steel.

Does anyone have any experience of these kind of installs? Any advice would be gratefully received.

 

[telectrix]

are you sure of the roof material. it's not asbestos is it? never heard of corrugated cement.

 

[SolarCity]

The roof was installed in the late '80s as far as the owner is aware so I was hoping this would mean that there is no asbestos in it.

I wouldn't let the corrugated asbestos sheets prevent me from installing PV panels on it - with precaution, I'm pretty sure that its legal.

 

[Markc]

Hi BiggsSolar,

Nothing is saying you can't install on Asbestos roof......However......You have a duty of care over all the other occupants or personal on site under the HSE. You may find this a little more to the point of restricting an installation. Your risk assessment for one would be to get the material tested and certified by a registered company in case it Does contain asbestos. You can not take just anyone's word for it. Even though you will not be drilling it you are still as risk of breaking sheets etc. This would release the dust fibres into the working environment below. HSE would go mental if you haven't identified the risk. A system of that size and environment might attract the attention of a passing HSE man who has the power to place a prohibition notice and stop work instantly. On that size system Ican only imagine your financial outlay.

Not knocking you but may be need to check it out?

 

[goodwilld]

The owner of the commercial building has to by law have an ACM certificate as do all commercial premmises since may 2004, these reports will tell anyone doing intrusive works o mater how big or small where and what contains asbestos.
you will be suprised what contains asbestos.
the answer is straight forward--don't touch it untill you find out if asbestos is presant, or you won't know what has hit you if the HSE get involved. You both have a Duty of Care.

 

[SolarCity]

I think we will get it checked. As far as I am aware, if it is asbestos, it can be managed with PPE. Either way, we'll make sure that everything is in place before we sign contracts.

 

[goodwilld]

Biggsolar
You can not cover the danger with PPE, i do H&S training which includes asbestos, take it from me, even to get is assesd and a ACM type two certificate can cost a lot of dosh. Go on the HSE web site and check it out.

 

[grantr37]

dont touch it even with a barge pole, if you touch asbestos without a licence, they will come down on you like a ton of bricks and shut down/ heavily fine you....and if you start disturbing Asbestos anywhere near other Humans, they will put the lot of you in Jail!!! there will be a prohibition notice on this buildings roof just nobody will know that it was automatically designated as a health risk, it is not cement, it is Asbestos fortified Cement.
There are a lot of buildings in the town near me that are fully constructed from this stuff (old vehicle service Garages) and a lot of Farm sheds, there are construction companies desperate to get the land to build blocks of flats, but they cant afford to pay the money it would take to have them demolished and disposed of, you cant just drive a digger through them, its all plastic tents and big fans, specially suited and booted workers with Asbestos Handling certificates......a big money business.......and as usual the recruitment agencies are trying to get a slice of the action, but with next to no success
The general opinion with the Health and Safety is just leave it alone, dont touch the old buildings, dont use them even for storage, dont go inside them, keep out keep away and at some point when theres money available they will pull them down....they are just left standing...
Theres one vehicle Garage still going here, they tried to sell it for housing land, and a special order was put on it, they couldnt sell it and were told that they had to relocate, I dont know how they are still operating from the building as the get out or cease trading order was put on them 3 years ago now...

Asbestos Roofing is also too weak to support any weight and somebody could end up going through it and straight down, I imagine that would be 50ft onto concrete, just something to think about...

 

[SolarCity]

By HSE A9, I thought we were ok to work on it. We can have the area shut down while we fit the panels (the unit isn't occupied at the moment yet) and we'd use crawling boards anyway.

If we win the job, we'll take a sample from the roof to get checked out - before we sign contracts. Frankly, if it is asbestos, and it takes us a week longer to install because of this, we'll still go for it. And we'll be sure to keep on the right side of the HSE.

 

[ian.settle1]

By HSE A9, I thought we were ok to work on it. We can have the area shut down while we fit the panels (the unit isn't occupied at the moment yet) and we'd use crawling boards anyway.

If we win the job, we'll take a sample from the roof to get checked out - before we sign contracts. Frankly, if it is asbestos, and it takes us a week longer to install because of this, we'll still go for it. And we'll be sure to keep on the right side of the HSE.

If you have already given them a price you will be making a big, big loss on it with all the extra safe guards you will have to put in place if asbestos is found.

But some how I don't think you are listening to what peiople are trying to tell you.

 

[SolarCity]

But some how I don't think you are listening to what peiople are trying to tell you.

Exactly how have you come to that conclusion?????

I will write it into the quote that the price is based on a successful asbestos test and I think that should keep me protected.

Does anyone know how much an asbestos test generally costs? If it is expensive then I'd be reluctant to do it before a successful quotation.

 

[goodwilld]

BiggsSolar
Why bother joining these forums and asking questions, to which you don't listen to the answers from the experienced members in the know!!!!
Do what you want to do, probably the worst decision in your life.
Crack on

 

[SolarCity]

BiggsSolar
Why bother joining these forums and asking questions, to which you don't listen to the answers from the experienced members in the know!!!!
Do what you want to do, probably the worst decision in your life.
Crack on

the answer is straight forward--don't touch it untill you find out if asbestos is presant, or you won't know what has hit you if the HSE get involved. You both have a Duty of Care.

To which I replied:

"I will write it into the quote that the price is based on a successful asbestos test and I think that should keep me protected.

Does anyone know how much an asbestos test generally costs? If it is expensive then I'd be reluctant to do it before a successful quotation. "

I've re-read this thead and I am staggered at the last two responses.

 

[edexlab]

Re Asbestos tests. A firm i worked for used to send samples away and this cost between £25 and £55 this may have been a special price for volume
I've been on several asbestos courses and i think that most electricians will have had exposure to the fibres without realising it,as it can be present in a lot of items eg artex ,bituminous adhesives, old 3036 fuseholders /consumer units,switchgear ,(roofing) asbestos slate ,flues the list goes on and we've all worked on building sites where some demolition has been taking place .So you can't do anything about the past ,but as long as you're sensible and get proper advice on how to work when you do come across it and following guidelines ,then there's no reason why you can't.
As for these cement fibre roofs Asbestos was apparently used pre 1974 but taking into account for stockpiling I'd assume its in all of this type of roofing until post 2004 when it was banned
We're currently getting a few enquiries on these kind of roofs so been doing my research my main concern is the scaffolding/safety nets etc required
and method of work i can see these jobs being too expensive and awkward to do

As for fixing to wood purlins hanger bolts are used (same as in slate roof thread) as this would mean drilling through
the asbestos, so you should spray water as you drill, another method is to use shaving foam as this prevents particles becoming airborne .The way I'd do it is to spray water / pva mix as you'll be to and fro over several days kicking up the dust from the day before so this should be minimised by the glue
the above ideas are recommended by HSE but check for yourselves first!

 

[goodwilld]

Soz matey, i didn't see your post at the top, i just follwed my link from email which takes you to the relivant reply.
Just you go steady and cover all your basese.

 

[SolarCity]

As for these cement fibre roofs Asbestos was apparently used pre 1974 but taking into account for stockpiling I'd assume its in all of this type of roofing until post 2004 when it was banned
We're currently getting a few enquiries on these kind of roofs so been doing my research my main concern is the scaffolding/safety nets etc required
and method of work i can see these jobs being too expensive and awkward to do

I spoke to a friend yesterday evening who reckons that working off crawling boards with foam padding are the way to go. Working on them is definitely a concern, but to be honest with you, the size of the job is so large and the prospect of further work is so great that I am desperate not to let it slip through.

If it turns out that working on these roofs is simply no-go, then so be it. If it turns out that the jobs can be done, if correctly managed, then I've never shied away from that - especially not on a job this scale.

 

[jerriais]

Just a thought, could you get some wood profiled to the shape of the corrugations in the roof, then contact a professional adhesive supplier, glue the wood onto the roof, get a struc engineer to calculate the relevant loads that this could hold, then put your fixing screws down into the wood, sounds like a bit of a hassle but if you avoid even touching the asbestos then it might be a better option?

 

[goodwilld]

jerriais
Would that hold for 25 years????

 

[jerriais]

To confirm that is the struc engineer's job (based on advice from the adhesive suppier), not my field so I'm not sure myself but if I got it in writing that it would I'd be happy to go with it.

 

[SolarCity]

Just a thought, could you get some wood profiled to the shape of the corrugations in the roof, then contact a professional adhesive supplier, glue the wood onto the roof, get a struc engineer to calculate the relevant loads that this could hold, then put your fixing screws down into the wood, sounds like a bit of a hassle but if you avoid even touching the asbestos then it might be a better option?

Interesting idea but I'm not sure I like the idea of it. The corrugated board would be taking a lot of the weight, no matter how well you fitted the panels and I can just see panels ripping the corrugated board off the roof.

 

[jerriais]

You're probably right, the forces acting on the panels wouldn't be transferred back down through the structure so it probably would be too much for the corrugated board to handle. So the best solution if it is asbestos is to get it all removed by a specialist asbestos removal company and refit with something like the Solar Century Energy Roof, then the customer get's a new non-toxic roof and a solid PV system.

 

[grantr37]

forgedaboutit........its just a load of trouble waiting to happen, if they are using an old crappy building like that what are they doing paying out 100k or something for Solar panels? sounds just like one of those times when the customer gets you to shell out then goes belly up owing you loads-o-money....then you go belly up.....how on earth did they get planning permission for that, number 1 it would be an eyesore, number 2 there is not a chance that the council planning would allow a roof like that to be touched....

 

[SolarCity]

forgedaboutit........its just a load of trouble waiting to happen, if they are using an old crappy building like that what are they doing paying out 100k or something for Solar panels? sounds just like one of those times when the customer gets you to shell out then goes belly up owing you loads-o-money....then you go belly up.....how on earth did they get planning permission for that, number 1 it would be an eyesore, number 2 there is not a chance that the council planning would allow a roof like that to be touched....

The company has a load of property in Birmingham and London. They generally take on old industrial buildings and convert them into cheap rent office space. They've been going ages and we've done loads of work for them in the past. We couldn't be more confident that they won't go belly up on us. Their buildings generally receive a lick of paint and retain their industrial look. While it would be nice if they changed the roof, it's just not the way they work. With this in mind, we anticipate a lot of potential work from them in the future and are eager to deal with this problem rather than let is slip by.

As far as I was aware, none of this proposal comes under planning law.

 

[edexlab]

I don't think adhesive would work these roofs are usually covered with lichen, which would need removing first ,read today on a asbestos website that this was not a good idea as in the removal process ,this would release fibres to a greater extent than just working on roof .
Also these panels typically contain around 13% cryolite or white asbestos which is harmful.
Apparently this type does'nt require a specialist removal firm and you can dispose of it at most recycling/waste depots. Makes you think whats in the air at the local tip, at my local facility its put into a big covered skip which has a lid and fibres must come out everytime its opened and closed .In the main they say follow the safe methods of work ie disturb as little as possible ,but the bigger risk is falling through the fragile roofs

 

[edexlab]

heres alink to one of the pages i got some of this info from www.aic.org.uk/asbestos_cement.htm

 

[Morgan keith]

We just come across a similar obstacle so I called the HSE and this was the outcome. Because really the only way you are disturbing the abestos is by drilling it, it is classified as a non-licences task as stated here https://www.electriciansforums.net/attachments/a9-pdf.120194/ . They said you HAVE to go on an asbestos training course (which is usually about 1 day) to learn safe working practices and how to drill properly and wrk with asbestos safely etc and also this book is apparently essential Asbestos essentials - HSE Books .
What are peoples thoughts on me thinking this is sufficient to carry out the work? Cheers

 

[SRE]

Just about to install on a corrugated concrete roof that was erected last year. Using hanger bolts - if the wind drops I'll let you know how it goes by the end of next week.

 

[SolarCity]

We'd be interested to hear how you get on.

This job has been put on the back burner for the moment (due to other issues) but we're still keen to get it and work around the potential problems. To be frank, if these jobs come off like we anticipate then it will be the most lucrative lines of work I have done since I started in 1992.

 

[SRE]

We seem to be working on a number of 10kwp systems that are taking ages to work through - as you say if they come off it'll be great but we're a bit worried about the time it's taking to pull everything together. I suppose once one comes through, in theory the rest will follow on - ever the optimist!

Our latest problem is trying not to void a warranty on a new commercial building that's going up.

 

[JSS]

We have just installed a 10kW system on a corrugated cement roof into steel purlins. We used a fixing from Schletter.
See link showing video YouTube - FixE_Einfachbefestiger_auf_Stahl
Bit expensive as we had to buy through a distributor as Schletter had not got themselves set up to supply in the UK yet.
Worked very well!!!

 

[SolarCity]

They're just what I've been looking for. Did they seem secure enough when they were fixed to the purling? Any lateral movement? And did you break and boards while you were installing?

 

[JSS]

No Absolutely spot on!!!
I spent 3 days literally sat in front of the computer searching for them. Every company I had spoken to about mounting on this type of roof suggested hanger bolts.
All the stress is on the spacer rather than the board.
No movement at all. The only way they were going to move was if the whole building came with them!!!!!!

 

[SRE]

Thanks JSS - for your info, Schletter's available from Waxman Energy and that's the system we've been looking at as well as Schuco.

 

[SRE]

No Absolutely spot on!!!
I spent 3 days literally sat in front of the computer searching for them. Every company I had spoken to about mounting on this type of roof suggested hanger bolts.
All the stress is on the spacer rather than the board.
No movement at all. The only way they were going to move was if the whole building came with them!!!!!!

Did you come across problems with voiding the warranty by drilling into the z's? Our customer seems to think that it will void the 30 year warranty if the z's are breached.

 

[SRE]

I've been checking out the warranty issues with this type of install because we had a customer with a new commercial building that he wanted to install pv on. This is the response from the technical guy from the roof manufacturer after I'd sent through the video of the Schletter fixings:

I did have a look at the video, found it a bit scary. Not keen on cutting holes in the sheeting, metal spacers which will cause thermal bridging or the small sealing washers which didn’t really look up to the job although the video related to single skin sheeting and --- are proposing to use insulated panels so that should do away with the need for the metal spacers.
I have attached the terms and conditions for our AS35 panel warranty. Section 4.6 says that the warranty does not apply to damage or failure resulting from modifications or alterations to the panel after installation and I feel the fixing method you are proposing would be covered by this.
You will see from the panel terms and conditions that Steadmans warrant that the panel will perform to its original specification for its guaranteed period but the coating of the panel is covered by the coil manufacturers warranty. I am still waiting for a reply from the coil manufacturers with their comments on how fitting the solar panels may effect their warranty.

So in a nutshell the 30 year warranty is void once we've drilled through the roof. I know this is different to the original query about corrugated concrete but it's very relevant to a lot of commercial installs.

 

[GreggElectrical]

Not sure if you are ok to work on it but licensed contractors are. A company I used to work for often came into contact with asbestos in schools and hospitals. The general rule was get it checked if you are unsure. You would be surprised how many times a building was checked for asbestos and given the all clear only to be found later on by a plumber or electrician. Usually the asbestos stayed as long as it was stable but the work of fixing cables etc was given to a specialist contractor and we kept well away!

I would expect everyone on here has had contact with asbestos at some time but are probably unaware, it was in everything at one point! You know the old school plug in pot fuses? they have a white powdery fabric flash guard underneath them. Guess what, its asbestos! Now how many times have you pulled one of them fuses out and some of the powder has escaped? I tell all my lads not to touch them DB's. If you are employing people you are putting them at risk as well as the buildings occupants.

Having said all that there are many materials that look and feel like asbestos but are not asbestos. As said before, get it checked is my advice.

Interesting point is that asbestos deaths are increasing year on year even though it has not been in use for over 25 years.

 

[JSS]

Further to a few replies; firstly this was definitely a concrete fibre roof, so asbestos was was not an issue. Seccondly, in the application we used them there were no guarantees to void so they worked perfectly.

 

[SRE]

Great news - has anyone any solutions to newer roofs with the guarantees though?????? We've got 3 jobs that we've been snookered with because of the warranty issues...

 

[SRE]

BiggsSolar - roofing kit went on on Friday - 1 day for 9.8kwp's worth of roofing & first 6 panels - all went on like a dream. Rest of panels going on tomorrow.

Might be a stupid question but are roofing kits covered by MCS? I don't think they are but I've got a customer who is a fabrication welder and he thinks he can get round his 30 year warranty issue on a new install. I'm thinking that if a structural engineer reckons it's sound and we can fit the appropriate rails it might be ok. Any thoughts??

 

[SolarCity]

Nice work, SRE, that's good going.

Regarding the mounting kits, I think they need to be to a certain standard of steel that won't degrade in extreme conditions, rather than an actually have to be certified by MCS.