Mounting for steel sheet roof tiles

[SpitfireW'sale]

We have a customer installing on Decra steel sheet roof. It is a corrugated steel sheet that is made to look like tiles. They are nailed to a wooden sub structure. Has anyone fitted onto this roof covering type before, and if so what type of fixing did you use to attach the rail?

We have considered most types of anchor, and none seems ideal for one reason or another. Hangar bolts could be used, but we normally recommend people avoid this for anything other than a more typical corrugated roof, typically found on commercial premises.

Thanks

 

[John Allen]

Would something like this work for you?

http://conergy.co.uk/Portaldata/1/R...-roof/SunTop_Trapez_TD_ENG_2011-06-01_web.pdf

 

[John Allen]

Or how about page 10 on this one?

http://www.knowyourplanet.com/technical-documents/wurth/Wurth Solar Mounting Systems.pdf

 

[SpitfireW'sale]

Thanks for the suggestions, but I don't think these would work, as they are for trapezoidal section sheet metal, which has a smooth texture and flat shape. The roof in question is metal, but shaped and textured like a tile. I'm not sure if the link below is the exact type, but close enough to give you a better idea.

http://www.decra.co.uk/~/media/DecraUK/Download%20Files/bba-3122ps1i1-decra-classic-decra-plus.pdf

 

[John Allen]

Ah I see. Have you tried speaking to DECRA direct to see if they have a solution.

 

[Gavin A]

hanger bolts are about the only option here IMO.

probably use nogins to give lateral adjuestment to make sure the bolt can go through the ridge of the corugated tile to ensure there will never be any water proofing issues.

 

[Gavin A]

obviously pilot drilling the bolt hole is a must or it will split the noggin, but I shouldn't need to say that.

 

[SpitfireW'sale]

hanger bolts are about the only option here IMO.

probably use nogins to give lateral adjuestment to make sure the bolt can go through the ridge of the corugated tile to ensure there will never be any water proofing issues.

That's a good idea. Also have a concern that the thread for the hangar bolts may thicker than is ideal for the rafters, and therefore could weaken them. If they were to fix into a noggin this would remove this concern.

We have some decent roofing sealant we can supply with this to assist waterproofing. It isn't a perfect solution, but as you say, probably the only one in this case. Thanks for the replies.

 

[Gavin A]

The concern with noggins is that it places the hole in the felt in the middle between the rafters where water run off will run if the seal on the tiles / ridge etc goes, so water is more likely to find the hole made, whereas if mounted to the rafter this is usually a high point so any water will tend to run off away from the rafters.

On the flip side of that coin though, if this does happen, at least it won't cause the actual rafter holding the roof up to rot, only the noggin supporting the solar PV.

rafters not splitting is a positive as well, the negative being that the main forces are running across the grain on the noggin, and across the shorter span, whereas they're mostly up the rafter IYSWIM.

swings and roundabouts.

 

[Worcester]

Re Hanger bolts - check the baxi fixing for their solar thermal - this method could work well here, - or have a look at the dulas fixing. CT1 is a great sealant - probably the best - it's NOT silicon and is a proper BBA approved construction material.

I know SOMEONE on this forum has already done one of these roof probably about a year ago, just can't remember who... oh yes - aha - SolarCity and solarsavings have both done it before.

 

[Worcester]

Strongly recommend giving Decra a call direct.

From what I remember, the lower row is interlocked from the row above, so you literally can't lift out one of the panels (one panel is made to look like a number of tiles)

You either have to take them apart from the top, or screw through them. - It may be easier to install a 'built in' system like intersole by the time you've finished.

 

[Dils]

Sorry to bring this old thread up.

What fixing method did you use in the end.

 

[SpitfireW'sale]

We recommended as per post #6 from GavinA and designed the mounting system and PV system around that. Unfortunately the installer took the design and went elsewhere, so I couldn't say for sure what was used! In this case our efforts went unrewarded :-(

 

[Gavin A]

We have a customer installing on Decra steel sheet roof. It is a corrugated steel sheet that is made to look like tiles. They are nailed to a wooden sub structure. Has anyone fitted onto this roof covering type before, and if so what type of fixing did you use to attach the rail?

We have considered most types of anchor, and none seems ideal for one reason or another. Hangar bolts could be used, but we normally recommend people avoid this for anything other than a more typical corrugated roof, typically found on commercial premises.

Thanks

yes.

We installed noggins between the rafters to line up the bolts with the ridges in the 'tiles' / sheet, then used hanger bolts (drill holes from the outside first, then install the nogin below the hold, then drill pilot hole in the noggin from outside, then drive bolt in) with a dollop of butyl sealant for good measure.

Actually the one we did was aluminum, but same principle, though you'll have to make doubly sure no steel is exposed to prevent rust.

eta - ah, that'll teach me not to read the thread eh. Still, at least I'm consistent.