corrugated metal roof with steel frame fixings

SolarRoofSols · Nov 28, 2012

just looking at a 50kW on a corrugated metal roof on a steel frame. It is crinkly tin, not trapezoidal, with some insulation sheeting underneath. The only fixings recommended so far are Schletter Fix E but they look fiddly to install and am yet to fins a uk supplier with some in stock.

Can anyone recommend a fixing for this? ideally we wanted self tapping hanger bolts but the only ones for metal frames I can find are Schuco but these are for trapezoidal finishes.

Gavin A · Nov 28, 2012

what's the depth from the top of the corrugated section to the top of the supporting horizontal Z bar sections?

We've done similar using cruciform mounting, with horizontal rails run all the way across above the horizontal Z bar supports, and fixed at regular intervals every 50cm or so using 6.5mm x 80 / 100mm self tapping bolts with the water proof washer, and some form of rubberised water proof mat under the fixings, using these schuco trapeze brackets, with the bolts tapping into the Z bar below. To be on the safe side for wind loading at the edges we usually extend the rails outwards beyond the edge of the panels to stop the wind being able to loosen the first fixing and then effectively unzip the array one fixing at a time.

Then using the little L cruciform brackets to run vertical rails off them for landscape mounting of the panels

SolarRoofSols · Nov 28, 2012

Thanks Gavin, not sure what the measurement is yet as only had prelim meetings with the client.

We have some of the schuco left over from another project - would love to get rid of it but as we are on a sinusoidal (so i have learned today!) roof - on first thoughts, I wouldn't have thought that those would be suitable. Do you have any pics of the one you have done like this?

I have come across a company called Ejot who supply self tapping hangers for steel substructures. We are getting a sample so Ill let you know what we think

jason121 · Nov 28, 2012

schuco do a 125mm hanger bolt, but be careful that they are not to long. you will have to drill an 6.7mm pilot into to the purling then self tap hanger bolt after, then attach the L bracket mount rails and make sure there level,
Gavin idea saves alot of time though there will be about 1400 stitching bolts to screw in.

Gavin A · Nov 28, 2012

jason121 said:
there will be about 1400 stitching bolts to screw in.

indeed. and you've got to make sure they've all hit the Z bar as well really unless the metal sheet is thick enough to get a good enough fix into.

it's only about 20-30 seconds per bolt though, and we'd usually have one of us doing that solidly, another following up with the cruciform rails, and another pair starting at one end with the panels, then the first pair start on with the panels from the other end once the rails are all done and meet in the middle (we always allow at least one 50cm gap in the middle for access for cleaning, maintenance etc usually 3-4 on bigger arrays, plus it allows us to work from both ends inwards.

jason121 · Nov 28, 2012

or Bulb-tite blind rivets never used them yet

SpitfireW'sale · Nov 29, 2012

We do a fixing which is identical to the Ejot, but significantly cheaper. We stock 4 different sizes so you can be sure you have the correct amount of thread to go through the insulation layer and into the purlin by the required amount. Feel free to email for details if required.
Thanks

SolarRoofSols · Nov 29, 2012

Thanks Spitfire, i have just pm'ed you. I did look on your website but could only find the schuco bolts for wood.

SpitfireW'sale · Nov 29, 2012

You're right, just had a look and they are not on there, I'll get that fixed! We do have decent stocks of this item though.

SolarRoofSols · Nov 29, 2012

Cheers Spitfire - just asked Alex to send some tech info on the bolt. it is loads cheaper than Ejot and if you have them in stock then that is even better.

Do you have to pilot this one, or is it self tapping?

SpitfireW'sale · Nov 29, 2012

They are self tapping - meaning that they create their own thread in the metal purlin and so make a good fixing point. They are not self drilling, and so you do need to pilot hole each one. I believe you need a 6.7mm drill bit for each one. (This is the same as the Ejot)
We have 150, 175, 195 or 230mm all in stock. Thanks.