Installing a mounting system on a Lead Roof?

[Ren-Age]

Hi everyone,

I am currently designing a PV system for a listed, gabled, Church roof which has a 'Lead' covering (never designed one for this type of roof before)

Has anyone done a similar job and if so did you use 300mm hanger bolts and were there any other issues I should know about?

Many thanks in advance

 

[telectrix]

careful when mentioning lead roofs on open forum. pikey might be watching.

 

[Ren-Age]

Well if I need help taking it off then I know where to post

 

[jupestar]

Be careful on a lead roof, we have done one and it is a nightmare. Ideally you want to go through the wooden rolls as this is where there is less movement, but this is normally impossible as they are not sat on the beams, and just nailed to the boards, and i guess it is low pitch so getting in to add rafters is going to be a tight squeeze if it is possible.

Hanger bolts are about the only solution but be warned lead is like a living thing it is always moving so just cause the rubber washer is closing the seal it doesn't mean it will be in 6 months time.

We took advice from some lead roofers, told them what we were trying to achieve, how we wanted to do it.. and eventually after lots of pursed lips they decided it could be done but the only way was slow and painful..

I really recommend getting advice from someone with experience, first time i mentioned it to our roofer he ran a mile.

 

[Cider]

What sort of lead roof is it? Flat with roll mops or standing welts? or is it sloped?
As said you need to find the timbers to join into but lead has a high coeficient of linear expansion so is always on the move. Restrict it and it cracks or buckles.
Worse case scenario is the lead would have to come off to have fixings built into the substructure and the lead re fitted around it. £££££
Of course the easiest way is to use ballast trays or similar it it is flat or construct a frame above the lead.
Think you will really need to involve an archietect which the diocese may insist on anyway.

 

[Ren-Age]

Thank you for your advice, I will now try and get more info on the substructure and lead type.

 

[JohnBoyZ]

Your a brave man! Not only a lead roof but listed! Have they got listed buildings consent yet? Don't forget listings officers can be a pain in the proverbial and they generally have the last word so make certain whatever design you come up with is agreed before starting.

 

[midsummerenergy]

I've just been looking back at these useful posts while researching a lead roof project. I also got in touch with the Lead Sheet Association and they have a useful publication (also from 2011) which covers their recommended way to secure panels to lead roofs. Posted here for the record: Rush for clean energy raises concerns for lead sheet - the article is on the second page.

 

[Gavin A]

I wonder, have they factored in that the panels will shade the lead so that the lead under the panels won't really suffer from thermal expansion?