Artificial slates at 15°

[Edddd]

Background in this thread: https://www.diynot.com/diy/threads/...he-tiles-arent-suitable-for-the-pitch.539954/

I'd like to replace a roof covering with 15° pitch. Artificial slates would be preferred because they'd match the rest of the building and I think the rafters are undersized for the weight of tiles.

A few makes of artificial slate claim to work at 15°. Does anyone have any experience if this is credible? In this case of SVK, for example, it seems to be a more recent widening of the specification and they suggest that the underlay will be doing some of the work.

Product:
https://svk.uk.com/en-GB/slates/Ardonit-Smooth

Technical data for low pitches:
https://a.storyblok.com/f/51041/x/4...echnicaldata_slates_lowpitchroofs_2018-01.pdf

I'm also interested in fitting a roof window. If some seepage is expected through the slates then presumably the correct installation of an underlay collar becomes critical?

I'd be grateful for your opinions and experience!

 

[bobasd]

why change your roofing conc tiles?
the slates you ref should be kept off that roof - why, because they are too fragile for the inevitable traffic that will result due to "ridge" and side abutments and any roof window
installation.

why dont you keep it simple and fix the roof as was suggested in your previous thread - or strip and re-fix the Marley's?

 

[Edddd]

Existing tiles aren't rated for the pitch and they leak all over the place.

But maybe they'd get by refitted at 100mm headlap. New underlay would keep it dry anyway. And I take your point about them being walked on.

Seems though if the whole lot is going to be stripped I might as well fit a covering rated for the purpose.

 

[datarebal]

Do it properly, those are not right for the pitch, Underlay shouldn't be relied of to keep the rain out.

Who goes walking on a slate roof?

 

[bobasd]

OP,
with respect for your pitch calculation but from that photo to my eye that pitch is above 15* - fwiw: if you want to give me a couple of measurements i'll give you your pitch, and you can prove me wrong?
rafter section sizes have not been posted?
lift a couple of tiles and your headlap will be exposed for a pic?

 

[bobasd]

read my post about that roof and you will learn.

you are a strange roofer if your not aware of characters who will walk on any roof?

 

[Edddd]

Height: 800mm bottom of joist to bottom of rafter at the top wall
Horizontal span: 2900mm top wall to inner edge of wall plate
I also used a pitch finder app on a rafter, which also said 15°

The rafters are 4x2

Headlap I measured as 65mm by poking a tape measure between two tiles from below, hooking the bottom of the upper tile and measuring to the top of the lower tile.

 

[datarebal]

65mm on the tile you measured , anyway its not enough. and probably 100 mm wont be enough unless your very sheltered.

you are a strange roofer if your not aware of characters who will walk on any roof?

is that a question?
next time we work on a cathedral ill suggest marley ludlow plus so that the rope access guys dont walk on the slates

 

[bobasd]

dont be such a saddo - man up, and get on your knees in any "cathedral" you visit, & ask forgiveness for dishonest ducking and diving.

are you a child? do you think that claiming knowledge of:
cathedral work & rope access will have the DIYNOT community going "OH MY GOD, gee whizz, is there no limit to this guy?"

by the way, didn't you notice that the OP's roof has, & will have, certain particulars, & a certain kind of slate?
what a very strange roofer you are indeed, to propose roofing a cathedral with "artificial slates"?

 

[Alastairreid]

lol bob, ree, vin... care in the community.

Chimney sweep come master builder.

 

[datarebal]

dont be such a saddo - man up, and get on your knees in any "cathedral" you visit, & ask forgiveness for dishonest ducking and diving.

are you a child? do you think that claiming knowledge of:
cathedral work & rope access will have the DIYNOT community going "OH MY GOD, gee whizz, is there no limit to this guy?"

by the way, didn't you notice that the OP's roof has, & will have, certain particulars, & a certain kind of slate?
what a very strange roofer you are indeed, to propose roofing a cathedral with "artificial slates"?

oh dear ...who do you think does that work lol .. obviously not you
https://photos.app.goo.gl/LFcGjzCCbAJPptSg9

https://photos.app.goo.gl/DtfimkbQbeYp1Qoz6

there is nothing strange or tricky about the ops roof.. unless your a jobber

 

[bobasd]

"strange or tricky" who, besides yourself, has said that about the OP's roof?

or is it a case of you finding the OP's roof a roof too far without the aid of "rope access guys"?
listen, if someone is confusing you then just let me at him, i'll show him the ropes! By God i will.
by the way, particular does not mean "strange or tricky" - just saying.

but tell me, how on earth did you get from the OP's roof to a cathedral - did you swing there?

 

[bobasd]

to Ali the sewer man,

well whadda you know, here pops up Ali the sewer man freshly bruised and aching from last nights painful defeats - at what time did you slink away and leave the fun.
the suffering you've endured over the last 24hrs might be just what you need - they say suffering aids the illiterate, and might cure those that cant stop sniffing manholes and drainage pipes.