Flat Roof Mounting systems

[ian81]

Can anyone pass on any advice for mounting to a flat roof??? Ive tried solion kits, however the customer is requesting that the panels are laid completly flat on thier back (Any advice on the pros and cons of this would also be good!!!!). The roof covering is a soft material and they would prefer if it wasnt punctured ion any way shape or form!! Any help would be much appreciated.

 

[Worcester]

ian81,

PM me, it's a standard 'membrane roof' (feels like a soft plasticky rubbery thing) we install on these without making any penetrations whatsoever - it's easy when you know how, got another two to do over the next 4 - 8 weeks.

 

[Ramjam]

We would use Ubbink consoles from Alternergy, bloody marvellous, 4no 25kg bags of sand in the console, panel bolted, job done 4kWp on a flat roof in a day no problem.

I appreciate that they aren't flat like your customer wants but the panels are only self cleaning when inclined over 20degrees so flat on their back is bad from productivity and cleaning point of view as well as being a mounting nightmare.

Consoles are not structural and as such don't require planning permission....ground mounted no planning, flat roof, protruding over 200mm no planning... brilliant things!

 

[SolarCity]

Consoles are not structural and as such don't require planning permission....ground mounted no planning, flat roof, protruding over 200mm no planning... brilliant things!

I've always gone through the planning process with the ConSoles. Are you sure it is PD?

 

[BruceB]

We would use Ubbink consoles from Alternergy, bloody marvellous, 4no 25kg bags of sand in the console, panel bolted, job done 4kWp on a flat roof in a day no problem.

Consoles are not structural and as such don't require planning permission....ground mounted no planning,flat roof, protruding over 200mm no planning... brilliant things!

Ground mounted as PD only allows upto 9m2, which is not much.
Surely consoles are >200mm high?

 

[SpitfireW'sale]

It is my understanding that Consoles will require planning since they will sit more than 200mm from the roof structure. We always recommend people seek permission before installing these. I have however not heard of a case where they have not been allowed. (assuming the array is not in an area of natural beauty, listed building etc.)

In terms of laying panels flat, as Ramjam suggested they won't self clean. There will also be a considerable drop in yield from mounting them at the correct angle for the array location. The slight benefit is that you can fit a larger PV array in the same area, which whilst inefficient, may yield more power (in total) than a mounted system. I would not recommend installing a system in this way however.

 

[Worcester]

We would use Ubbink consoles from Alternergy, bloody marvellous, 4no 25kg bags of sand in the console, panel bolted, job done 4kWp on a flat roof in a day no problem.

I appreciate that they aren't flat like your customer wants but the panels are only self cleaning when inclined over 20degrees so flat on their back is bad from productivity and cleaning point of view as well as being a mounting nightmare.

Consoles are not structural and as such don't require planning permission....ground mounted no planning, flat roof, protruding over 200mm no planning... brilliant things!

Holy smoke that's heavy! That works out wth the console at about 120kg / module, I sure hope you've got the structural calcs for that.

We install fully structural non-penetrating roof mount systems that weigh less than 20kg / m2 and are fully wind lift and overturning resistant.

Also becasue you are > 200mm what legislation have you used to class it as permitted development?

I can't see any way that you can get away without planning permission when putting those on a roof, - though I may be wrong ( I frequently am!)

 

[Ramjam]

If it's not fastened to anything then it's doesn't require permission. No different to you putting your handbag on the roof or leaving 16 bales of silage in the field.

 

[BruceB]

If it's not fastened to anything then it's doesn't require permission. No different to you putting your handbag on the roof or leaving 16 bales of silage in the field.
.

I doubt you will find that phrase in the permitted development rules!
The difference is that the intention is to leave the PV there for 25 years.

I would be delighted to be shown ConSoles do not require permission...

Regards
Bruce

 

[solarcat]

Solarcentury have a system called Fast Sun: 10 degrees tilt and not much ballast required. But they only supply with panels within their range.

 

[craignmick]

Flat Fix is always an option, they can be ballasted by concrete slabs at the back. Carbomat offer them.

 

[Antscran]

We offer a system that uses a 12.5 deg tilt it consists of an Aluminium frame and ballast, we have used this on membrane roofs so no penetration of the roof skin is required. This system also uses minimum ballast as it incorporates a wind shield, if the calculations are made regarding wind zones on the roof and the panels placed accordingly, minimal ballast is required which further limits the stress on the roof skin. A recent system I designed on an industrial roof approximately 10m in height we have kept the loading down to 38kg/m2 (panels, under construction and ballast), this is also dependent on your geographical location however!

 

[Greenman Solar]

ian81,

PM me, it's a standard 'membrane roof' (feels like a soft plasticky rubbery thing) we install on these without making any penetrations whatsoever - it's easy when you know how, got another two to do over the next 4 - 8 weeks.

Good morning, first post on here, but have been following the fantastic discussions and advice for months, thanks to all.

We have a handful of flat roof installs coming up two of them are re-roofing so are incorporating our mounting brackets into the new roofing mambrane and structure. The other 3 need to be mounted flat at 0 degrees inclanation on an existing surface, we would prefer not to penetrate at all so any advice would be very welcome.

Thanks

n

 

[Worcester]

@Greenman, Panel warranty will almost certainly be invalidated at 0°

There are two solutions
1) From Schletter - They have a System FixZ-7 which kicks it up a few degrees without losing a lot of roof space, Systems for pitched roofs | | 1 | Schletter GmbH
2) We buy a low angle mount, reduced roof loading system from these guys : Mountings « Avontech Renewable Solutions

 

[calhalla]

Does anybody on here have experience fitting the Ubbink Console, and what amount of ballast have they put in?

We're putting 10kW of HJ Solar 250W mono's onto a flat roof (rubber membrane, no penetration possible). The building is two stories high, with a small (approx. 1m) parapet.

Looking at the ConSole installation guide it seems that the weight of the ballasted ConSoles vary from 83 kg in the middle of the array to 134 kg on the edge of the array due to the wind loading on the outer rows of consoles.

Does 134kg of ballast seem excessive?

 

[Ramjam]

Having gone though all the calcs etc we just use 4 bags of sand, each 25kg, easy, cheap and plenty of weight and they sit nicely in the bin.

 

[calhalla]

Thanks Ramjam.

Do you put more weight in the ones on the outer rows?

Can you recommend a good product to keep the cables protected and tidy on the roof?

 

[edexlab]

We're doing our first ground mounted console job, concrete is in place inverter will be a 4000TL in an enclosure and I'm wondering what to do regarding bonding the array as the individual panels although butted together are not in good contact so it seems that we'll be bonding each panel and taking to a spike ,can anyone who has done these advise whether they do this or is there a better method ?

 

[Antscran]

We have built larger ground mounted systems using a piled system and tables constructed of Aluminium, we joined each table together with an earth link to ensure all the tables and panels are at the same potential.

 

[Antscran]

Thanks Ramjam.

Do you put more weight in the ones on the outer rows?

Can you recommend a good product to keep the cables protected and tidy on the roof?

The roof will have wind zones which usually go from A to D on a flat roof or more depending on the roof type, A is usually a corner zone, B the edge zone nearest the gable, then C and D. The ballast requirements are usually greater in zones A and B, so by avoiding these zones you can reduce the overall load on the roof. Also by decreasing the angle of the system can aid in reducing the ballast, a good system for this is made by Schletter called Alu-Light which only inclines the panel at 12.5 deg, the system is also made in a box style shape so helps to funnel the wind away and reduce uplifting and sliding due to wind pressures.

 

[alexpau]

Hi

if you need ny help let me know i am a solar PV specialist for Hilti