Jump to content

Dormer cladding and lead flashing


Recommended Posts

Hi all, me again looking for yet more of this wonderful forums collective knowledge.

 

Weve got a dormer which is now going to be clad in horizontal timber cladding. So onto the frame will be a 25mm vertIcal batten and then the horizontal cladding. 

 

Its seems (from reading) that conventional wisdom is to slate the roof first with the appropriate front lead apron and soakers. Then add the timber cladding.

 

However, the disadvantage to this plan is that I will need access across the slates to do the cladding which will risk damaging my 5mm thick nailed slates. 

 

I mentioned this this to a roofer I know today and he said (in something of a hurry as he was heading off to a job); "definitely clad it first, add a lead apron over the vertical battens, set off from the roofing battens (using a piece of timber) and then when you slate tuck your soakers under that apron".

 

At the time that seemed to make sense. Now I've thought about it, I'm not really sure I understand the detailing :( 

 

Can anyone shed any light or suggest another way? 

 

A picture for clarity:

 

20170615_170414264_iOS.thumb.jpg.98c70d8e61ed15f4bf0aa5e023e0b5e5.jpg

 

 

Thanks

 

Link to comment
Share on other sites

What he means is put a single length of lead at the lowest point of the dormer cheeks following the rake of the roof. If it is longer than 1.5m then use another piece to allow for expansion and overlap by at least 100mm with second piece. If you measure how thick your slates are then that will set the bottom edge of the lead piece you are going to attach to the cheeks and along the front under the windows. The top edge of this lead will be covered by your battens and wood cladding,

When you make your soakers they are L shaped, one part goes under your slate and the the other part, the vertical up stand will then tuck under your lead piece on the dormer. Each row of slates has a soaker which is nailed to the batten and turned down past the top edge of the batten.If you imagine putting a 75mm strip of lead under the lead piece on the dormer and a 75mm piece under each slate with a 90 degree angle between them this may help, all using one piece of lead. 

Where it gets tricky is doing the dormer corner detail as you will either have to beat the lead to shape or you can buy pre made lead corners on the web or ask your roofing guy to make them for you. If it was my roof on a brand new build I would get some lovely lead welded corners to finish of the job properly. hope this helps. 

Link to comment
Share on other sites

33 minutes ago, Pete said:

What he means is put a single length of lead at the lowest point of the dormer cheeks following the rake of the roof. If it is longer than 1.5m then use another piece to allow for expansion and overlap by at least 100mm with second piece. If you measure how thick your slates are then that will set the bottom edge of the lead piece you are going to attach to the cheeks and along the front under the windows. The top edge of this lead will be covered by your battens and wood cladding,

When you make your soakers they are L shaped, one part goes under your slate and the the other part, the vertical up stand will then tuck under your lead piece on the dormer. Each row of slates has a soaker which is nailed to the batten and turned down past the top edge of the batten.If you imagine putting a 75mm strip of lead under the lead piece on the dormer and a 75mm piece under each slate with a 90 degree angle between them this may help, all using one piece of lead. 

Where it gets tricky is doing the dormer corner detail as you will either have to beat the lead to shape or you can buy pre made lead corners on the web or ask your roofing guy to make them for you. If it was my roof on a brand new build I would get some lovely lead welded corners to finish of the job properly. hope this helps. 

 

Thanks Pete, I think I've got that straight in my head. Where I'm still confused is how you tuck the soaker under the lead piece? Surely the lead piece attached to the cheeks has been trapped by the battens and cladding? 

Sorry if I'm being thick !

 

Edit: Answering my own question. Do you stop the battens 75mm short of the slate line to enable it to be tucked up? Presumably also stopping the cladding short of the slate line is also good detailing to stop it rotting from water running down the roof?

Edited by Barney12
Link to comment
Share on other sites

Just make sure you leave enough room to slide your soaker in, it is only around 75mm ish Do not nail/screw within that zone when fixing vertical battens and cladding and you should be ok,As you are fixing the lead piece to the dormer first you can nail that at the top edge and then carry on cladding the dormer being mindful of not nailing/screwing below that line.  

Link to comment
Share on other sites

Your slates will be 10-15mm thick with laps where you are talking about so I would do it "properly" and get a couple of decent crawler ladders and final fix the cladding after the slates and lead. 

 

It will look better than a bent apron and be neater around the cut edge

Link to comment
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now
×
×
  • Create New...