Geekzone: technology news, blogs, forums
Guest
Welcome Guest.
You haven't logged in yet. If you don't have an account you can register now.


timmmay

20575 posts

Uber Geek

Trusted
Lifetime subscriber

#208082 26-Jan-2017 07:35
Send private message

I have a single 40W solar panel that I'd like to mount to my shed's corrugated iron roof without drilling holes in the roof. Reason is I don't want to create a leak and I'm only ok at DIY. I could pay someone, but that's not the kiwi way. 

 

The place I bought my solar panel said I could bolt the panel onto some 2cm thick wood rails, then silicone the wood to the roof. The wood is to create a small air gap, to keep the panel cool. I think he suggested attaching the wood down the long side of the panel, leaving only the shorter top and bottom open, to reduce wind going through but still giving enough cooling. This is in Wellington, which you may be aware gets some wind.

 

An alternate approach is these brackets, made for caravans, which do appear to regularly be attached with silicone. Caravans aren't corrugated though.

 

Does this sound reasonable to anyone? Is silicone strong enough to hold a solar panel to a roof in Wellington reliably? If it comes off it in a storm could really hurt someone, probably me.

 

 

 

Panel Dimensions: 670 mm × 420 mm × 30 mm

 

Panel Weight: Weight: 3.1 kg 

 

Use: running small greenhouse ventilation fan, keeping emergency batteries charged


Create new topic
wellygary
8312 posts

Uber Geek


  #1709738 26-Jan-2017 07:59
Send private message

NO!, do not use silicon to hold a 3Kg panel to a corrugated roof in Wellington, the corrugations will mean tha actual contact area with the roof is very small...

 

Just screw it on, if you screw into the "high" parts of the corrugated iron and through to the purlin below and then apply silicon to the holes you will be fine, rain goes down the "low" parts of the corrugations

 

If you are wanting to use a price of wood to increase airflow, thats fine, but again screw right through it and the panel to the roof below....

 

 

 

 

 

 

 

 




Cody64
28 posts

Geek


  #1709739 26-Jan-2017 08:02
Send private message

Can you use brackets that can be screwed down by removing some of the existing nails then use sealer and long tek screws in their place? As the screws are on top of the corrugations there is less chance of leakage.


timmmay

20575 posts

Uber Geek

Trusted
Lifetime subscriber

  #1709743 26-Jan-2017 08:18
Send private message

Ok, sounds like I'll have to actually screw it on if I want it outside. Right now it sits inside the shed in the window, gathering only a little bit of sun. I might have to get mounts and have someone else mount it to roof for me - I think I know a guy who can do that.




MikeAqua
7773 posts

Uber Geek


  #1709753 26-Jan-2017 08:43
Send private message

Regular silicon is more of a sealant than an adhesive.  Modified silicon is a bit more adhesive.

 

3M make a product called 5200.  It will hold just about anything to just about anything.  It's also often used as a gasket between two materials that are screwed together to avoid point loading.

 

I would be slightly concerned about only using screws for your solar panel.

 

Roofing steel is quite thin, so generally you only have 1 - 2 threads gripping it.  It's easy for a screw to gradually rock out over time.  At the very least you would want screws with wide threads and plenty of them.

 

Ideally you would use roofing 'tek' screws and fix into the purloins underneath the roofing steel. They have excellent holding power.  That's how the professionals installed the brackets for our solar water.





Mike


timmmay

20575 posts

Uber Geek

Trusted
Lifetime subscriber

  #1709755 26-Jan-2017 08:50
Send private message

That kind of product is more what I'm talking about I think, a silicone based adhesive. But it could put a lot of load onto the paint that's on top of the roofing iron.

 

Sounds like the best option might be to use some spare roofing screws to screw some metal rails or feet to the roof, then use some kind of bolt system to attach those to the panel. Like these.


tieke
674 posts

Ultimate Geek

ID Verified

  #1709805 26-Jan-2017 09:32
Send private message

I attached a small panel to a corrugated roof by attaching some pieces of wood onto the roof for the top and bottom of the panel. I also didn't want to make any new holes, so just unscrewed two existing roof screws for the end of each bit of wood and then rescrewed these through the top of the wood with rubber washers underneath. I countersunk the holes so that the screws wouldn't poke out, and also drilled holes through the wood so that it could sit flush over the in-between roof screws.


timmmay

20575 posts

Uber Geek

Trusted
Lifetime subscriber

  #1709809 26-Jan-2017 09:37
Send private message

Would I need longer / wider screws if I take existing screws out and want them to go through 1-2cm of wood? Otherwise the screws won't go down as far as they did before and may not bite into good solid wood.

 

Sounds like a pretty good compromise solution. I could also use some of those metal brackets in the current holes, if they line up properly, which seems unlikely.


 
 
 

Cloud spending continues to surge globally, but most organisations haven’t made the changes necessary to maximise the value and cost-efficiency benefits of their cloud investments. Download the whitepaper From Overspend to Advantage now.
richms
28168 posts

Uber Geek

Trusted
Lifetime subscriber

  #1709812 26-Jan-2017 09:43
Send private message

The normal way to install panels is to put rails across the outside over where the wood is, and then the panels are held onto those with holddown clamps. Looks expensive for just 1 panel to go to all that effort. I would see if some L brackets would line up with the roof screws and the side of the panel at all.





Richard rich.ms

timmmay

20575 posts

Uber Geek

Trusted
Lifetime subscriber

  #1709818 26-Jan-2017 09:45
Send private message

I guess I could attach the Z brackets to the roof wherever suits, then screw into the panel frame wherever I like. Should be easy enough actually.


SCUBADOO
192 posts

Master Geek


  #1709844 26-Jan-2017 10:08
Send private message

Don't use silicon!

FWIW

No screw or rivets involved. (-;

I have 2 x 300W 23kg solar panels mounted on the fibreglass roof of our motorhome on 6 aluminium right angle 250mm brackets made from 50x50x3mm extrusion.
They are attached with Sikaflex 11FC sealant/adhesive.
Allow an air gap between your roof and the panels to improve output in hot weather.

2 years later, 40000km and frequent 100km/h speeds. They are still there and operating perfectly.

blakamin
4431 posts

Uber Geek
Inactive user


  #1711303 29-Jan-2017 13:09
Send private message

We used an industrial version of this from bunnings for holding ACM to sign frames and trailers. Your panel would go nowhere.

 

 

 

Edit: What the post above mine said, basically, but with a link.

 

 

 

Besides the rivets holding the checker-plate on, those big panels are held on with the same type of stuff... this is a racing car trailer.

 


timmmay

20575 posts

Uber Geek

Trusted
Lifetime subscriber

  #1711306 29-Jan-2017 13:15
Send private message

I might use the Z brackets with the existing roofing screws anyway, with the panels bolted on. Seems like the easiest way. If I'm feeling paranoid I might put some of that onto each side of the Z bracket, but then getting it off could be next to impossible.


blakamin
4431 posts

Uber Geek
Inactive user


  #1711308 29-Jan-2017 13:27
Send private message

You can cut it with a razor blade.


SCUBADOO
192 posts

Master Geek


  #1711328 29-Jan-2017 14:29
Send private message

Piano wire works well also.

Create new topic





News and reviews »

Air New Zealand Starts AI adoption with OpenAI
Posted 24-Jul-2025 16:00


eero Pro 7 Review
Posted 23-Jul-2025 12:07


BeeStation Plus Review
Posted 21-Jul-2025 14:21


eero Unveils New Wi-Fi 7 Products in New Zealand
Posted 21-Jul-2025 00:01


WiZ Introduces HDMI Sync Box and other Light Devices
Posted 20-Jul-2025 17:32


RedShield Enhances DDoS and Bot Attack Protection
Posted 20-Jul-2025 17:26


Seagate Ships 30TB Drives
Posted 17-Jul-2025 11:24


Oclean AirPump A10 Water Flosser Review
Posted 13-Jul-2025 11:05


Samsung Galaxy Z Fold7: Raising the Bar for Smartphones
Posted 10-Jul-2025 02:01


Samsung Galaxy Z Flip7 Brings New Edge-To-Edge FlexWindow
Posted 10-Jul-2025 02:01


Epson Launches New AM-C550Z WorkForce Enterprise printer
Posted 9-Jul-2025 18:22


Samsung Releases Smart Monitor M9
Posted 9-Jul-2025 17:46


Nearly Half of Older Kiwis Still Write their Passwords on Paper
Posted 9-Jul-2025 08:42


D-Link 4G+ Cat6 Wi-Fi 6 DWR-933M Mobile Hotspot Review
Posted 1-Jul-2025 11:34


Oppo A5 Series Launches With New Levels of Durability
Posted 30-Jun-2025 10:15









Geekzone Live »

Try automatic live updates from Geekzone directly in your browser, without refreshing the page, with Geekzone Live now.



Are you subscribed to our RSS feed? You can download the latest headlines and summaries from our stories directly to your computer or smartphone by using a feed reader.