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Russell griffiths

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Thinking out side the box,like I do

instead of using one of the in roof kits to fit your panels in, how about having a full GRP tray under the panels

our roof build up will end up with a full osb sheet under our roof covering, so I was thinking about having a complete fibreglass tray resin bonded onto the osb with any brackets bonded in 

an upstand all the way around covered with a flashing to match the metal roof covering 

 

any thoughts. 

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3 minutes ago, Russell griffiths said:

Thinking out side the box,like I do

instead of using one of the in roof kits to fit your panels in, how about having a full GRP tray under the panels

our roof build up will end up with a full osb sheet under our roof covering, so I was thinking about having a complete fibreglass tray resin bonded onto the osb with any brackets bonded in 

an upstand all the way around covered with a flashing to match the metal roof covering 

 

any thoughts. 

 

I've considered similar myself. 

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28 minutes ago, Ferdinand said:

It would be interesting to see a cost comparison vs EDPM.

 

I considered it for ST panels and EDPM was my first thought but thinking under the panels might get too hot?

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One thing to watch would be how to ventilate under the GRP in order to maintain vapour permeability.  The GSE/EasyRoof mounts have large ventilation holes in them, with raised edges, behind the panels, so that ventilation is maintained.

 

Not hard to make up a second skin fitted to counter battens, with a ventilated space underneath, and then cover that with GRP.  I think I'd prefer GRP to EPDM, as I suspect it may well last longer.

 

Come to that, why not make up a mould to make your own GRP panel mounts.  Probably only a day's work to make a mould up, and less than an hour to lay up each panel mount.

 

Or, easier still, make a simple wooden mould and vacuum form the panel mounts from a suitable sheet plastic.  There's lots of instructions on the web for DIY vacuum forming - it's not hard to do.

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If you were to get a few sheets of OSB, cut out the big holes needed for ventilation under the place where each panel is to fit (these also allow the cables to connect up), add some small battens to form up stands around the big holes that you've cut out, add panel mounting ridges with battens in the same way (the panel frames just slot over the raised lips and are held down with alloy clamps and screws) then lay up GRP over the whole thing, finish with gel coat and wax to give a good weather resistant finish, you should be able to make a mount that will work OK.  Whether it's cheaper than just buying the GSE/EasyRoof mounts I'm not sure.  There would be quite a bit of work in cutting all the big ventilation holes out and adding up stand frames around them all to deflect water out and around to the edges.

 

As mentioned above, it might be worth looking at making a mould up to get some mounts vacuum formed.  There used to be a place somewhere near Thruxton that did custom vacuum forming, and a timber mould is fine and would be pretty easy to make.  Not sure what custom formed ABS mounts would cost, but might be worth looking at.  The GSE mounts just slot together, with the U channel on one side being wider than that on the other, so they fit over each other.  They do have water deflection barriers underneath, above the big ventilation/cabling cut out that are designed to deflect water out to the sides and keep the bit of plastic at the top a bit stiffer.

 

 

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Two years ago I GRP our kitchen roof, the materials came to around £700 and the area is a fair size bigger than I would think a fairly standard array of panels would take up. 

Thats sort of why I asked recently how much room does a fairly standard set of panels take up. 

 

What meterage does yours take up @JSHarris

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2 minutes ago, Russell griffiths said:

Two years ago I GRP our kitchen roof, the materials came to around £700 and the area is a fair size bigger than I would think a fairly standard array of panels would take up. 

Thats sort of why I asked recently how much room does a fairly standard set of panels take up. 

 

What meterage does yours take up @JSHarris

 

Roughly 36m2 , but you definitely need the big ventilation cut outs, as without them I reckon the panels will seriously over heat.  As it is, in-roof panels tend to run pretty hot (it's not uncommon for our panels to hit 50 deg C), so there needs to be plenty of space underneath the panels to allow air to flow up and under them on a hot day, plus keep the rain out when it runs down behind the panels.

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49 minutes ago, JSHarris said:

 

Roughly 36m2 , but you definitely need the big ventilation cut outs, as without them I reckon the panels will seriously over heat.  As it is, in-roof panels tend to run pretty hot (it's not uncommon for our panels to hit 50 deg C), so there needs to be plenty of space underneath the panels to allow air to flow up and under them on a hot day, plus keep the rain out when it runs down behind the panels.

Maybe wriggle tin would help dissipate heat and the castilations in the tin help air flow.

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Possibly, but equally it may reflect back up a fair bit of heat to the underside of the panels. making them even hotter.

 

I think I'd want to have as deep a ventilation space under the panels as possible, as they do get pretty damned hot.  It'd be a shame to save a load of money on the mounts, just to bugger up a set of panels, or degrade their performance.

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This study examines the effect of air flow on a building integrated PV-panel. It is shown that in summer, the maximum temperature of a PV-panel of 3 m in height is experienced for an east facing surface and reaches 77°C early in the morning. The maximum temperature for a south facing panel is 51°C and that for a west facing surface is 58°C. The air velocity in the air-gap between the PV-panel and the building wall is an important factor. It is shown that for an air-gap width of 0.02 m, an air velocity of 0.5 m s–1 can lower the mean temperature of the panel from 77°C to 39°C, allowing for a significant increase in its efficiency. Finally the air-gap width is varied for a steady velocity of 0.2 m s–1, and it is shown that the temperature of the building wall varies from 23.7°C for a width of 0.01 m to 20°C for a width of 0.05 m.

 

https://ac.els-cdn.com/S2210983814000522/1-s2.0-S2210983814000522-main.pdf?_tid=060e3c00-f496-4490-a44a-f3aae7f4ff70&acdnat=1535403109_8406ce8e92e25da307d1c86f8e115edf

 

 

 

 

Edited by Triassic
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I wonder if it's worth investigating a group buy from a French retailer?

 

It seems that the GSE Integration frames are £35 each here (plus the cost of the flashing and panel mount clamps - although the flashing is nothing fancy and could easily be made up from standard alloy stuff).  If things are as they often seem to be here, and there's a big markup for stuff sold in the UK, then I wonder if it'd be worth trying to buy them from France?  In many areas of France there are laws/regulations that mandate the use of in-roof panels (presumably why the two main manufacturers are French).  Might be worth finding out if they can be bought more cheaply over there.  I (and @PeterStarck) saved a great deal of money by buying our MVHR units from Denmark, rather then the UK - they were thousands of pounds cheaper when bought from there.  Maybe the same applies to the in-roof panel mounts.  Using a purpose made mount gets around the SE fees for the structural integrity stuff as well.

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1 hour ago, Alexphd1 said:

I did spend a bit of time trawling the internet for GSE kit in Europe with no luck.

I would also be interested in a group buy aswell.

 

Wow they are a lot cheaper from France.

 

 I’d definitely  be interested in a bulk buy deal.

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Looking at the installation videos, it’s clear that there are a series of ‘other’ bits you need to carry out a full installation. So the price of €39 is misleading, as this is for the tray only. A quick look at a French web site suggests the flashing kit Extras add up to around €50 per panel. Mind you, that’s still cheaper than any UK supplier I’ve looked at !

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