Solar Limpets

[dansk]

Im going to use these on upcoming job - they only sell in box's of 25, any one got a few spare they wanna sell? i need 34 in total.

 

[SolarCity]

Let us know what you make of them. They look pukka in my opinion.

 

[dansk]

agreed, its a rosemary job, and they no more expensive than the Renusol hooks i buy, plus the saving in lead.

 

[SolarCity]

Looks like a quicker install too.

 

[dansk]

yep, i dont see any downside ATM.

 

[Worcester]

We're going to use these on a 9.5kw Plain/Rosemary tile install next week, so we'll take a few photos, -

Carl from Solar Limpets came out and cheked the roof over as these tiles are 11 x 7 not the usual 10 x 6 and he wanted to be sure that they'd fit OK, actually they fitted very well. He also offers free training, so he's coming out to get my tile roofing team trained up on the job. Can't really ask for better support than that!

@Dansk we may have a few over - bought 125 of them as we'll space them at 800 not 1200, As always we'll double up in the corner (400 spacing) and then stagger the fxings so that with 2 rows of panels there will be be 2 fixings on every rafter. (Guess it's the engineer in me to spread the load as much as possible )

 

[dansk]

Thanks Worcester that would be useful - this job of mines on 400 centres - only wish i was doing a 9.5kw - this is a baby 2.75!

 

[Worcester]

@Dansk your welcome

 

[LightGEN]

Looks OK for Rosemary tiles but i don't like their approach to dealing with slates - drilling is a no-no.

 

[Worcester]

It's quite an intersting discussion on slate - it's currently going through MCS012 for slate - the point is how it fits, where the loads are transferred to, how any holes are sealed. It is a lot better than a hanger bolt which has a movement / bending action / stress points around the hole. I am reserving judgement on slate at the moment. However as an engineer having been involde in constructionm for >30 years, i can see all the arguments. hence judgement reserved..

 

[Gavin A]

It's quite an intersting discussion on slate - it's currently going through MCS012 for slate - the point is how it fits, where the loads are transferred to, how any holes are sealed. It is a lot better than a hanger bolt which has a movement / bending action / stress points around the hole. I am reserving judgement on slate at the moment. However as an engineer having been involde in constructionm for >30 years, i can see all the arguments. hence judgement reserved..

I'm not sure I really want to get involved in this, but what "movement / bending action / stress points around the hole" are you referring to with a hanger bolt, and why do you see this as problematic?*

We've tried all methods (other than these limpets) and firmly believe that hanger bolts are by far the best mounting method for slate when installed by a skilled, trained team who understands how to do it properly.

I really don't understand why everyone on here is so obsessed with a method that involves ripping out 1/4 of the roof slates, cutting big holes in them and then relying on flashing over the top to water proof the roof.


*eta - or more to the point, what problems that can't be resolved simply by drilling the slates with a slightly bigger hole than the bolt, and ensuring the flexible sealing gasket isn't over-compressed. IME the actual flex on these bolts is minimal anyway, certainly a lot less so than brackets.

 

[ktech]

I am starting to agree with you Gavin, although we have not used it hanger bolts do sound like a good solution for slate. If a hanger bolt works for sheet fibre cement sheets why would it be a problem for slate? Very interested in the limpets though.

 

[ktech]

Just to add to previous: If it's a cheap chinese slate then we don't touch it anyway as it falls to bits. But a good quality thick Welsh slate is a different story.

 

[Worcester]

@Gavin A, you should watch the video of a hanger bolt when doing the wind and snow loading tests on any roof material. I've witnessed many tests of materials, loadings and fixings in test labs that accurately represent real world conditions, and it's scary what happens to the whole lot (they test them to failure)

I also concurr that unless you use a professional slate roofer, rippingout a bunch of slates to put a hook in isn't a good idea, a good slate roofer should end up with minimal disruption to the roof structure, it takes a lot longer though than any other method, also therir are very few hooks that are properly designed for UK slate roofs, you've got to hunt out those ones that do work properly, then trial them, test them, and get experience BEFORE you start on a real roof.

Ends hijacked discussion on hanger bolts, this thread is about Limpets. For hanger bolts see the lengthy discussions and numerous threads on slate fixings.

 

[Gavin A]

I am starting to agree with you Gavin, although we have not used it hanger bolts do sound like a good solution for slate. If a hanger bolt works for sheet fibre cement sheets why would it be a problem for slate? Very interested in the limpets though.

I'd think we've installed in the region of 30 systems on slate, yorkshire stone, cotswold slate, and fake slate roofs, as well as metal, and fibre cement. That's probably getting on for 1000 bolts installed, with zero reports of any problems related to the bolts, and no evidence of any problems at the few we have had call backs for for other issues.

We did have one scare with a 10kW installation involving about 100 bolts, when the building owner reported a leak a few days later. We put a hose on it on full blast for about 2 hours and couldn't replicate a leak at all. We eventually tracked the leak to the ridge that had worked its way loose when we were working on the roof. We've also tested another installation on a rough cotswold slate roof with a hose for a fair length of time as well, which also didn't show any problems up.

IMO the only reason these aren't rated for this purpose by the manufacturer is that whether or not it's water proof is largely down to whether the installer is a knows what they're doing or not. You do need to be careful with it, flash any that are close to the gap between slates or that give any other cause for concern, and obviously pre drill pilot holes through the centre of the rafters, but done right and I really don't see why anyone would have a problem with it.