Ive been saying this for years on more than one forum, I didnt get much support either. john.
Solar Panel Blown off Roof
- Thread starter stewartwebr
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cant understand why anyone would rely on just adeasive, its only as good as the paint its stuck to, whats wrong with a screw through them as well
scotjimland
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Very scary experience.. 
reminds me of the time the awning on my RV unfurled doing 60 mph on the M6 .. still gives me the shivers just thinking about it..
Just for info..
when I purchased my Alden AS 4 Auto Sat dish it was supplied with
Sika 252 + Sika Akitvator
There is no mechanical fixings or screws to hold it to the roof.. it has been on for over 3 years ..
this is the procedure, instructions by Alden
Sika 252 for fixing sat dish or solar panels.
reminds me of the time the awning on my RV unfurled doing 60 mph on the M6 .. still gives me the shivers just thinking about it..
Just for info..
when I purchased my Alden AS 4 Auto Sat dish it was supplied with
Sika 252 + Sika Akitvator
There is no mechanical fixings or screws to hold it to the roof.. it has been on for over 3 years ..
this is the procedure, instructions by Alden
Sika 252 for fixing sat dish or solar panels.
- Use a pencil to mark the place of the unit on the roof.
- Sand the roof surface with sandpaper.
- Clean each surface with a thinner.
- Spread Sika-Aktivator on the sanded surface.
Leave to dry for 15 to 20 minutes. - Glue generously the base of the unit with SikaFlex 252 then press slightly on the unit. Layer of glue: ± 3 mm.
- To accelerate the polymerisation, spray a little water on the visible parts of the glue.
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34127
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I found this on another forum a while back. It is a photo of a Fiat roof where the adhesive didn't fail but the paint came off the vehicle. Another argument for using screws or other mechanical fixing.
Basildog
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Most are using the wrong products .
Modern adhesive should be more than capable of doing the job but as with everything it’s about doing everything by the manufacturers instructions and not guesswork or making do with some alcohol cleaner you think is ok .
Attention to detail with surface preparation and using the Aktivator and 252i
Modern adhesive should be more than capable of doing the job but as with everything it’s about doing everything by the manufacturers instructions and not guesswork or making do with some alcohol cleaner you think is ok .
Attention to detail with surface preparation and using the Aktivator and 252i
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6 aluminium brackets, sikaflex and stainless steel screws in each bracket. Why risk killing someone?
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34127
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Also, if there was an incident that caused serious damage or harm then there would be an investigation to the cause and try to find if anyone had been negligent. If the panels were simply glued on and the joint failed then how hard would it be to prove you were not negligent and hence not responsible for the incident. I wouldn't like to be in that situation.
Basildog
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I would rather not bother with solar than drill holes in the roof but as I find solar pretty useless from September to April and don’t need it the rest of the year then maybe I won’t bother fitting any on this van
scotjimland
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we don't know what adhesive was used.. and clearly a bodge job
but in any case, clearly the preparation was poor.. or non existent, you can't bond onto paint, should have been sanded down to remove the paint. as per SIKA INSTRUCTIONS
with correct preparation, (as posted) and using SIKA 252 + Akitvator, it will never come off
there is no need to pepper your roof with screws..
If the adhesive fails due to using the incorrect Sika and or poor preparation, it's doubtful if a few self tapping screws will hold a heavy solar panel onto the roof.. IMV they will simply rip out ..
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I would never rely on any adhesive alone without mechanical fixing in such a situation.
The consequences of this could have been fatal just for a few screws.
The consequences of this could have been fatal just for a few screws.
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This is why I prefer the SemiFlexible Panels ensure the roof is clean and wipe IPA to give correct base contact then the adhesive is applied to the solar in lines every 100/150mm with a break in the middle to allow any damp/condensation to breath.
Done correctly it’s impossible for wind to pass underneath,quality units can be stood on if really nessasary to get about on the roof if it’s really busy up there as many are,it’s a win win situation.
Done correctly it’s impossible for wind to pass underneath,quality units can be stood on if really nessasary to get about on the roof if it’s really busy up there as many are,it’s a win win situation.
Wissel
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Turning into an interesting thread this.
Myself, I used Sika 252 attached to 25mm aluminium box the full width of each panel, with the panels Sika'd above. I did this to give maximum adhesion and an air gap under the panels. Rock solid after 6 years.
On my next conversion I've decided to fit two lengths of aluminium L bracket the full length of my roof. These will be stuck with Sika 252 again - and rivited. They will be the correct distance apart to rivit solar panels between them.
I'll paint the visible parts of the brackets to match the van before fitting - should make the panels quite hidden (and still an air gap). Doing it this way in case a panel ever fails and needs replacing.
Myself, I used Sika 252 attached to 25mm aluminium box the full width of each panel, with the panels Sika'd above. I did this to give maximum adhesion and an air gap under the panels. Rock solid after 6 years.
On my next conversion I've decided to fit two lengths of aluminium L bracket the full length of my roof. These will be stuck with Sika 252 again - and rivited. They will be the correct distance apart to rivit solar panels between them.
I'll paint the visible parts of the brackets to match the van before fitting - should make the panels quite hidden (and still an air gap). Doing it this way in case a panel ever fails and needs replacing.
Lenny HB
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Nothing wrong with adhesive if the correct adhesive has been used correctly. Self-tappers into very thin alloy aren't going to do much.
If you are going to use screws you need to put a spreader plate on the inside of the roof and bolt though to that. How many of you who advocate the use of screws have done that?
Don't notice cars driving down the road with bits falling off them, most car front wings and various other bits are glued on with PU adhesive.
If you are going to use screws you need to put a spreader plate on the inside of the roof and bolt though to that. How many of you who advocate the use of screws have done that?
Don't notice cars driving down the road with bits falling off them, most car front wings and various other bits are glued on with PU adhesive.
Scary stuff! Thanks for letting us know. And kudos to you for putting your hand up and saying it was you who fitted the panels. I suspect some would have hidden behind the event happening to a ‘friend’.
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Wissel was it you I sold the Sika 252 to? john clark
DBK
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Good point about self-tappers into thin aluminium. The roof of our PVC is steel of course and the screws grip very well.
Steve and Denise
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Of course they will - tiny self-tappers into a couple of mm of aluminium or GRP. Aeroplanes, cars, and wind generators, are being glued together these days some of which might be subject to higher stresses than a solar panel
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You won't find that in a modern roof.
I do the same as you plan to do but I use Rivnuts & 5mm stainless screws. That way I can easily remove the panel without drilling rivets. (Belt & braces in case the connections to the panel fail.)
Wissel
Free Member
Yep
Many of us have motorhomes that are basically glued together! seems to be holding together so far.
better than a dreamliner anyway.
Composite materials
Disassembled composite fuselage section of the Boeing 787
The 787 is the first major commercial airplane to have a composite fuselage, composite wings, and use composites in most other airframe components.[213] Each 787 contains approximately 77,000 pounds (35 metric tons) of carbon fiber reinforced polymer (CFRP), made with 51,000 lb (23 t) of carbon fiber.[214] Carbon fiber composites have a higher strength-to-weight ratio than conventional aircraft materials, and help make the 787 a lighter aircraft.[185] Composites are used on fuselage, wings, tail, doors, and interior. Boeing had built and tested the first commercial aircraft composite section while studying the proposed Sonic Cruiser in the early 2000s.[215][216] The first carbon/epoxy primary structure was put into service on the Boeing 737 Classic horizontal tail in 1984, and the largest use of composite structures is 60 percent in the Boeing–Sikorsky RAH-66 Comanche.[217]
Carbon fiber, unlike metal, does not visibly show cracks and fatigue, prompting concerns about the safety risks of widespread use of the material;[80][218][219] the rival Airbus A350 XWB uses composite panels on a frame, a more conventional approach, which its contractors regarded as less risky.[81] Although fired in 2006, Boeing engineer Vince Weldon complained to management, and later to the public: the composite fuselage was unsafe compared to conventional aluminum designs, and in a crash, was more likely to "shatter too easily and burn with toxic fumes".[220]
In addition, a potential issue is the porous nature of composite materials: collected moisture expanding with altitude can cause delamination.[221] Boeing responded that composites have been used on wings and other passenger aircraft parts for many years without incident, and special defect detection procedures will be instituted for the 787 to detect any potential hidden damage.[222]
better than a dreamliner anyway.
Composite materials
Disassembled composite fuselage section of the Boeing 787
The 787 is the first major commercial airplane to have a composite fuselage, composite wings, and use composites in most other airframe components.[213] Each 787 contains approximately 77,000 pounds (35 metric tons) of carbon fiber reinforced polymer (CFRP), made with 51,000 lb (23 t) of carbon fiber.[214] Carbon fiber composites have a higher strength-to-weight ratio than conventional aircraft materials, and help make the 787 a lighter aircraft.[185] Composites are used on fuselage, wings, tail, doors, and interior. Boeing had built and tested the first commercial aircraft composite section while studying the proposed Sonic Cruiser in the early 2000s.[215][216] The first carbon/epoxy primary structure was put into service on the Boeing 737 Classic horizontal tail in 1984, and the largest use of composite structures is 60 percent in the Boeing–Sikorsky RAH-66 Comanche.[217]
Carbon fiber, unlike metal, does not visibly show cracks and fatigue, prompting concerns about the safety risks of widespread use of the material;[80][218][219] the rival Airbus A350 XWB uses composite panels on a frame, a more conventional approach, which its contractors regarded as less risky.[81] Although fired in 2006, Boeing engineer Vince Weldon complained to management, and later to the public: the composite fuselage was unsafe compared to conventional aluminum designs, and in a crash, was more likely to "shatter too easily and burn with toxic fumes".[220]
In addition, a potential issue is the porous nature of composite materials: collected moisture expanding with altitude can cause delamination.[221] Boeing responded that composites have been used on wings and other passenger aircraft parts for many years without incident, and special defect detection procedures will be instituted for the 787 to detect any potential hidden damage.[222]
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DBK
LIFE MEMBER
A good question.
All I can say is from what I could see of the underneath where the screws were to be put there was no wiring. The screws are right at the edge of the roof and I don't think any of the vehicle wiring runs along the inside of the roof, it mostly seems to come from the floor and rear corners.
Are you saying that on for instance my Hymer a class the roof has no internal framing, I am surprised .
My last RV in avatar had aluminium box section framing in walls and roof which I secured my solar panels to in addition to adhesive.
Basildog
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If your HYMER is like our new one it’ll be made of old egg boxes stuck together with toffee and chocolate
If your HYMER is like our new one it’ll be made of old egg boxes stuck together with toffee and chocolate
Wow egg boxes, I bow to your incredible knowledge
Basildog
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Wow egg boxes, I bow to your incredible knowledge
The loading for a person going onto the roof is only 75kg so only midgets and anorexic’s
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