mounting systems for welsh slate roof

[Worcester]

The boys at work (also posted elsewhere!) http://bit.ly/SlateRoofInstall , Anyone at Segen in Sept I'll be at the bar, thirsty

@alexpau

Paul, many thanks for the photo's , that's a neat and tidy installation (although it looks like someone's practice / training roof rather than a real world situation ) , however I'd be really interested in your interpretation as to whether the photo you sent is Eurocode 5 compliant and how you interpret that. Thx

 

[NicoGoodwin]

Hi GPack
Hilti do the 'normal' slate bracket for those tiles although you will still have the problem of trying to remove the slates as carefully as possible and then replacing with lead flashing is the easiest solution so I believe. The brackets do have a thickness so can still push up the slates if they are not cut in between them
Good luck
Nico

 

[alexpau]

Hi Worcester. All Hilti rail mounting products are Eurocode compliant including the roof screws ( i believe we are the only manufacturer who have roof screws supplied with our mounting systems which are). The issue is if the screws i.e. 8mm or 6mm comply with building regulations as most european roofs are boarded and dont use rafters and battens like we do in the UK. If the roof timbers allow the use of 8mm or 6mm screws them our products comply. The issue is for example if the roof timber is 80mm wide then if you drill into the centre of the timber ie 40mm then the diameter of the drilled hole cannot be bigger than 10mm to comply with building regs this is partly the problem in why you cannot use hanger bolts for fixing slates as they will not allow for compliance with building regs in UK roof timbers.

Regards

 

[Worcester]

@aelxpau

The issue is for example if the roof timber is 80mm wide then if you drill into the centre of the timber ie 40mm then the diameter of the drilled hole cannot be bigger than 10mm to comply with building regs this is partly the problem in why you cannot use hanger bolts for fixing slates as they will not allow for compliance with building regs in UK roof timber

Hi Paul, thanks for that so if a rafter has to be 80mm wide before you can install an 8mm hanger bolt, which Hilti products installed in which manner are Eurocode 5 compliant on a standard UK 35mm wide rafter?

i.e What do you have and how do I fit it to a 35mm wide rafter and comply with Eurocode 5?

Thanks

 

[alexpau]

Hi

Worcester HIlti have just launched a 6mm diameter holed roof hook ( in pantile initially) which has three rows of 6mm holes along with 6mm screws which comply with Eurocde and GB codes along with the 6mm screws again which have been tested and approved and come as part of our 10 yr system warranty. As i mentioned before a potential problem within the industry is not just if the mounting kit is approved its also the roof screws used to tighten down the roof hooks, if for example you purchase your mounting kit from a supplier and you get your roof screws form somewhere else what happens if the screws of system fail i.e. the screws corrode or the system break under load who do you go back to? the chances are the mounting kit manufacturer will not except liability, Hilti are the biggest construciton fixing company in the world and we system sell ( not part systems) so we warrantee the entire system as long as its installed to manufacturers specification for 10 yrs under our company insurance.

Regards

 

[rt1200]

Thanks for providing the link to the azur roof hooks. I think this is an excellent anchor for slated roofs - the best Ive seen with respect to strength and durability with regard to the detailing. I believe the Schucco slate anchors have a neoprene gasket and use the under slate virtually as packing? If this is correct, and please forgive my ignorance, but will the azur hook accept the other components of the schucco mounting system?
Thanks for your advice.

 

[Worcester]

@rt1200 Should do no problem it just has a slotted hole for an 8mmm S/S Nut/bolt (We use A2 grade S/S with penny washer and shakeproof washer, 8mm set screw and plain nut or alternatively a nylock nut.) We've used it with various rail systems mounted on it.

 

[Worcester]

@alexpau,

As most people here know hanger bolts etc are my 'bete noir', Could you please forward the approvals to me, I actually have one of the hooks that you talk about, even posted a pic of it on here not long ago:
and here's the azur one : both on a 35mm piece of tanalized timber.

Base on the Eurocode rule of 4 x diameter from edge, how does the 6mm x (4+1+4) = 54mm still work on the 38mm rafter?

Also as it is staggered, it won't be even 4 x . Eurocode 5 table 8.6 attached:


Or Am I missing somethong here?

I'd really like to see a copy of those approvals, then you'll get my full endorsement. You have my email address.

 

[alexpau]

Hi I will send you the information you need just a quick note with regards to using a companies roof hook with someones elses rail etc how will you cover this under warranty as most manufacturers offer around a 10 yr warranty on there mounting systems this would not apply if you mix manufacturers systems as its only complete systems which carry the warrant. i.e. Azur roofs hooks with Schuco rail!

 

[MikeXl426]

@alexpau,

Please could you send the info on to me too? I have been following this on other threads and getting equally concerned and frustrated over the use/mis-use of roof brackets and hanger bolts. A PM should do it.

Thanks

Mike

 

[rt1200]

Hi I will send you the information you need just a quick note with regards to using a companies roof hook with someones elses rail etc how will you cover this under warranty as most manufacturers offer around a 10 yr warranty on there mounting systems this would not apply if you mix manufacturers systems as its only complete systems which carry the warrant. i.e. Azur roofs hooks with Schuco rail!

The point you raise is a valid one So I checked, through a contact, with Schucco. I included a photo of the Azur anchor that Worcester posted and here is their reply.....[FONT=&quot]
"The older type slate anchor Schűco manufactured in the PV Light 1 range had a neoprene backing to it and fitted on top of an under slate, but now we are onto MSE 210 the basic principles of fitting our slate anchors are the same as this installation you have attached.[/FONT]

This is reassuring, negates the requirement to mix and match and hopefully, most manufacturers have, or will go down this route.
another thing i thought about is that when you fix the anchor to a rafter, you must either:
1. notch the rafter or slate batten.
2. fix timber either side of the rafter to support the battens and cut the battens above the rafter, if that makes sense
3. Pack between the battens with something suitable and and fix the anchor or hook on top of the battens.

If you simply lift the battens and insert the anchors under, the batten fixings/nails will be less effective and the slates in this area will be pushed up.
I hope this makes sense.

 

[alexpau]

All this makes sense and and fixing to an under slate would be the correct thing to do, when fixing to a rafter or batten you may or may not need extra timber it really depends on the width of the timber to comply with Eurocode and Buiding regs. On 35mm - 38mm timber battens you should only be using stainless steel 6mm screws which have been approved for use with Solar PV systems.

 

[rt1200]

All this makes sense and and fixing to an under slate would be the correct thing to do, when fixing to a rafter or batten you may or may not need extra timber it really depends on the width of the timber to comply with Eurocode and Buiding regs. On 35mm - 38mm timber battens you should only be using stainless steel 6mm screws which have been approved for use with Solar PV systems.

I apologise alexpau as I have not made my self clear. For me having a slate between an anchor and a rafter is not acceptable as in this instance slate would not be a good packing material. All the slates have to come off, the anchor securley fixed to the rafter and then the slates replaced, cut around the anchor as necessary and a lead flashing fitted. The point I was making was the best place for the anchor is face to face with the rafter but this requires an alteration to either the battens or the rafter if everything is to sit flat again afterwards. If you ease up the batten and insert the anchor under, it will force the batten upwards thus arching the local slates upon completion. Sorry - I hope this is clearer.
Regards

 

[alexpau]

rt1200

I agree to the point that current slate hooks should be fixed to the batten/rafter as drilling through the tile is not ideal for various reasons and some installers do as you mention using a combination of flashing and cutting around the tiles to make a tight fit thus not causing issues such as water ingress or potentially breaking the tile when tightenign the hook down but you would be amazed how many roof installers are using slate hooks fixed ontop of the tile or even worse a hanger bolt which would cause potential long term warranty issues as a down force load would potentially break the tiles, our stance is clear we would not warrant hanger bolts for slate.

 

[rt1200]

Absolutlely. I have also posted with regard to structural assessment of the existing roof members and the potetial need for building regulations approval under Part A but I think this is still awaiting the ok from the moderator. It would be worthwhile having a look at that post and the links it contains, assuming it is accepted!!

 

[Dan]

Don't mind me while I bump some threads in the solar PV forum. If they're not current or applicable topics, just ignore the threads; they'll drop off the page. If they are, feel free to chip in and chat solar stuff in the solar panels forum.