navitron
 
Renewable Energy and Sustainability Forum
Welcome, Guest. Please login or register.

Login with username, password and session length
News: Anyone wishing to register as a new member on the forum is strongly recommended to use a "proper" email address. Following continuous spam/hack attempts on the forum, "disposable" email addresses like Gmail, Yahoo and Hotmail tend to be viewed with suspicion, and the application rejected if there is any doubt whatsoever
 
Recent Articles: Navitron Partners With Solax to Help Create A More Sustainable Future | Navitron Calls for Increased Carbon Footprint Reduction In Light of Earth Overshoot Day | A plea from The David School - Issue 18
   Home   Help Search Login Register  
Pages: [1]   Go Down
  Print  
Author Topic: Solar In Roof  (Read 846 times)
alwhitworth
Newbie
*
Offline Offline

Posts: 26


« on: March 15, 2020, 10:12:08 AM »

Last year I helped install an in-roof system on a house (at a silly price). Now thinking of solar at our place and wondering if anyone's managed to install solar as the roof itself? I have to rebuild my workshop so considering using the panels as the roof covering on the south side. I'm too stingy to pay for proper flashing kits for the panels so wondering about DIY, sizing the roof exactly for the panels.

Basically my idea would be rafters, ply, heavy duty breather membrane, then panels, using adhesive flashing to seal in-between and around the panels. I've used adhesive flashings before (not flashband, better ones) and they seem to be very strong. Any flaws in my plan?!

Alternatively I'll install them free-standing, but my concern is wind uplift (in N. Scotland). Plus, I don't have anywhere flat to install them, and all slopes face SW.
Logged
Countrypaul
Hero Member
*****
Offline Offline

Posts: 1671


« Reply #1 on: March 15, 2020, 11:32:12 AM »

I have an in-roof system that is effectively the roof itself for a large portion. I am not clear on what you expect the difference between an in-roof sytem and your proposed one to be. Our in-roof system uses plastic trays beneath the PV panels to ensure all water is discharged properly. Ours is over a SIPS roof, so a continuous OSB facing if you like, which is counter battened before the membrane and trays were affixed iirc.

How would you be fixing the panels to the rafters or are you planning on relying on the plywood? BC might want to see the calculations for roof loading if you are doing something non conventional.
You would probably still need to have the panels lifted off the ply/membrane but you don't mention how, otherwise any water that gets in (and it will one way or another even if just condensation) won't get out easily and could lead to  problems.
Logged
brackwell
Hero Member
*****
Offline Offline

Posts: 3266


« Reply #2 on: March 15, 2020, 12:19:04 PM »

I think you would only install a in roof system if you were interested in the cosmetics. Its probably not the cheapest nor the most efficient.  I would be looking at a factory type tin roof coloured and insulated sandwich constuction for warmth and condensation.  Fit PV on top.   Roof could possibly be picked up on E bay.
Logged
todthedog
Global Moderator
Hero Member
*****
Offline Offline

Posts: 4390



« Reply #3 on: March 15, 2020, 12:37:15 PM »

Lots of in roof systems in France when we lived there. Heard several reports of leaks. Could be installation rather than system.
Logged

Kidwelly South Wales
alwhitworth
Newbie
*
Offline Offline

Posts: 26


« Reply #4 on: March 15, 2020, 12:51:42 PM »

How would you be fixing the panels to the rafters or are you planning on relying on the plywood? BC might want to see the calculations for roof loading if you are doing something non conventional.

Yes panels would need to be fixed to rafters. The one I installed before wasn't battened, panels straight onto sarking with membrane over. The brackets held the panels up slightly so there was an air gap. Interestingly there wasn't any way of water getting out, should it get in somehow, but that is something to consider, thanks. They were very similar to Velux flashings. I don't think BC will be an issue as the shed should be exempt but I'll look into that first.
« Last Edit: March 15, 2020, 12:55:14 PM by alwhitworth » Logged
Countrypaul
Hero Member
*****
Offline Offline

Posts: 1671


« Reply #5 on: March 15, 2020, 01:01:31 PM »

How would you be fixing the panels to the rafters or are you planning on relying on the plywood? BC might want to see the calculations for roof loading if you are doing something non conventional.

Yes panels would need to be fixed to rafters. The one I installed before wasn't battened, panels straight onto sarking with membrane over. The brackets held the panels up slightly so there was an air gap. Interestingly there wasn't any way of water getting out, should it get in somehow, but that is something to consider, thanks. They were very similar to Velux flashings. I don't think BC will be an issue as the shed should be exempt but I'll look into that first.

Sorry I missed the fact you initially said it was a workshop, somehow I assumed that was part of the house. If on a shed then I would be surprised if BC were involved, but you might want to make sure that the wnd wouldn't lift things anyway.

Logged
olly12383
Newbie
*
Offline Offline

Posts: 5


« Reply #6 on: April 09, 2020, 08:33:16 PM »

I fitted an in roof system to a workshop here using the GSE trays - they are quite cheap and I needed no flashings because it fits the whole roof.  Lead ridge (which was second hand, on site, could have used something cheaper if I didn't have it).  Fascias lap onto the edges of the GSE trays (this is a custom made aluminium trim piece to match others on site, but if you didn't have a need to match things, then could be done cheaper.)
 Discharge straight into standard gutter.
It makes a little bit more than predicted over the year so far so does not seem to be any derating due to trapped hot air etc.
Good luck
Logged
Pages: [1]   Go Up
  Print  
 
Jump to:  

Powered by MySQL Powered by PHP Powered by SMF 1.1.20 | SMF © 2013, Simple Machines
SMFAds for Free Forums
Simple Audio Video Embedder
Valid XHTML 1.0! Valid CSS!