Slate Hanging... Felt or No Felt???

[LRich]

Hi all,

Slate hanging the rear of a stone built cottage in Devon.
Builder says he never uses felt under the slates for slate hanging, Slate Merchant say you must... So what's the answer?

I'm inclined to go with using felt myself, but I'd like a bit of backup before forcing it to the builder.

Speedy replies gratefully received

 

[Softus]

Slate hanging the rear of a stone built cottage in Devon.
Builder says he never uses felt under the slates for slate hanging

General builder? Or professional roofing specialist? (Do you get my point?)

Slate Merchant say you must... So what's the answer?

You must do what the manufacturer stipulates, or, failing that, what the supplier stipulates.

 

[LRich]

Hey thanks for the reply.

That's exactly why I want to go with the felt... I just want to hear it from a 3rd party.

 

[markie]

Maybe he thinks this will eat into his profits


http://www.screwfix.com/app/sfd/cat/pro.jsp?id=98160

 

[JohnD]

My slate-hung wall (faces the coastal weather) has felt behind the battens, but I should think the breathing membrane markie shows would be better.

BTW you will not want slates all the way down, they will get broken when you brush against them. I have shiplap for the bottom 2M with a dwarf wall to take it away from the ground.

Maybe felt was not used in the old days and your builder is following local practice.

If you are in a windy or coastal area, have non rusting (copper or stainless) nails, and have at least the bottom two courses centre-nailed as well as head-nailed to prevent storms lifting them. They can rattle excitingly if the wind gets under the edges.

 

[noseall]

regardless of pitch an underlay is essential, breathable, sarking or otherwise.

 

[LRich]

Thanks all

I've decided to get someone else in.
And there will be felt.
Thanks again

One last thing...
...behind the batons against the wall yes??

I lied... another thing...
Any suggestions for the finish on the 2 ends? for the depth of the baton etc?
And who uses what on corner cuts?
One guy says lead, t'other says DPM.

 

[noseall]

battens or lathes; 25x38mm. always use lead for any watertight fabrications at roof tile level.

 

[LRich]

Sorry to be dense here, but when you say roof level... do you mean on the roof, as this is on the wall?

This guy suggested cementing the 2 ends as repointing the side walls anyway. Do I take it you're suggesting capping down the ends with wood?

Appologies, I'm not quite with you.

 

[noseall]

where the roof tiles cannot cope with intricate details such as wall abutments, chimneys, valleys, dormers etc. then we use lead to deal with these scenarios.

i say at 'roof tile level' because below the tiles the roofing membrane deals with water ingress, i.e. underslaters sarking felt, tyvek breathable membrane, reinforced untearable membrane etc.