MCS NC - roofing advice please

[BruceB]

I would be grateful for some roofing advice. Just had my third MCS assessment after an 18 month gap and having got zero non-conformities on 3 technologies on previous assessments with two different inspectors have scored six NCs on this one with the third inspector. I showed him a PV installation I did days before the Dec 11 deadline, on my own property. Two arrays of 6x3 sanyo 240W in landscape format on a Schüco cruciform framework.

The issue is what to do about antique clay double roman tiles, common on old buildings around here. The assessors view was that I had left them standing too proud and that they must be lowered flush with the ones below. I have inserted some photos showing how much they stand up, having removed all the panels. Hope not compressed too much.





Unlike modern concrete double roman tiles there is not enough thickness in the tile to grind anything away without weakening it significantly. As it is on a curtilage listed building and the planning and listed building consents require that "the historic fabric shall be made good as soon as no longer required for microgeneration purposes", then it seem almost wanton vandalism to cut slots in the tiles like the ones in the single lap slate picture on page 74 of the latest MCS Guide and then use lead. It would be x48 tiles cut. My judgement at the time was that as the building was in a very sheltered location the slight lifting of the tiles was acceptable and the best compromise.

My options appear to be:
- argue the ----
- cut slots in the tiles and use some lead or equiv to flash the hooks in
- replace the upper tile completely with a piece of lead (that would be large and saggy)
- leave the tiles raised but put additional lead flashing in place to seal the gaps.

If I have done wrong, I will fix it, but I thought I made a reasonable decision at the time in Dec 11. Has anyone had this issue before and got a good answer?

 

[SolarCity]

It is difficult to see from the photos you have posted but they certainly don't seem to be raised very much.

I would agree with you that cutting the tiles would leave them too brittle and the listed building rules pretty much make the argument for you.

Perhaps another option would be some sealant squeezed into the gaps that have been left? A little rough, but it would solve the problem I would imagine.

I'm not keen on the idea of removing the tile completely and substituting it for lead to be honest.

 

[SibertSolar]

Dammit...the one time Bruce actually needs advice rather than providing it and I can't help! ;-)

I agree with Solarcity though - they don't look too proud of the adjacent tiles. Are they particularly thick hooks?

 

[BruceB]

Standard schuco hooks set with 5mm clearance from tile below

 

[telectrix]

this inspector... is this him?

 

[BruceB]

another couple of photos from a lower angle and with more pixels

 

[solarsavings]

Inspector never done the job at his best.

 

[taffbutc]

Hi Bruce

What if you slide the Upper tile to take it away from the bracket and then add lead (not so much lead that way). Where the cables come through the roof you can get proper lead flashing now as well. I one fit one of these and take a picture showing him how you have redone it.

 

[Gavin A]

I'd maybe flash the tiles at the edges where it's possible for wind to drive rain into the gaps, the rest of them should be fine IMO as the panels will protect them.

Send in the listed building officer agreement, and explain that a one size fits all policy can never apply to listed buildings, and to refer to english heritage if the inspector has any further queries on that point.

The roof is water tight as it stands, and the inspector obviously hasn't got a clue what he's doing - just a jobsworth IMO. Could try asking him how many installations he's carried out and what exactly qualifies him to voice opinions on roof work, chances are he's a spark who's done half a dozen installs at most (NIC thought they were doing really well to be making sure each of their inspectors had experience of at least 5 installs, which to me would put them in the trainee role at best).

 

[Gavin A]

ps you can't cut slots in those tiles, it would void the listed building consent.