Flashing the extension Roof

[pennelldj]

Hi Guys, wonder if you can help me, with the change in the weather have decided its time to sort the single storey extension roof out at the back of the house.

The lead flashing keeps falling out of the wall, I think partly becasue it runs the entire lenght of the roof which seems quite a long piece. i have removed the flashing and chizzled out the line cut onto the wall. Underneath there is a wooden batton with nails in it to which attached is another line of leading. The baton is coming away from the wall due to it being inappropriatley fixed to the wall.

My questions are: whats the best way to fix the baton to the concrete wall of the house, the best way to fix the leading to the baton? should the leading be in small strips? and can i not use lead strips can I use another material?

Also with the top line cut out of the wall what is the best way to keep the strips in? I have seen Hi-Tack Flashing Strip can this be used instead of lead flashing? Its hard to describe the wall but will upload picture, appreciate it you can suggest the best way to sort it all out

Cheers

 

[pennelldj]

Hi Guys heres the images of the wall and roof

 

[masona]

Best to chop out the rendering, lead against the wall then use render stop angle bead just above the top of the lead flashing and make good.

 

[pennelldj]

Hi Thanks for the reply, how far in the wall does the lead have to go?
and what is render stop angle bead?

also there are two layers of lead they have used the bottom layer is hooked onto a wooden beam with nails sticking out and a hole in the leading to hook it onto is this the best method?

Is there another material i can use instead of the leading?

 

[masona]

Hi Thanks for the reply, how far in the wall does the lead have to go?

Back to the brickwork

what is render stop angle bead?

Put the lead under the render stop beading then make good, use non rust screws/wide washers to fit the render stop beading.

Is there another material i can use instead of the leading?

There is but lead is forever

 

[pennelldj]

Hi thanks for the reply, I know im a complete idiot but i still dont get it

I have raked out the old render/putty that was used to plug the old lead into the wall - now I plan to place in the new lead - but I dont understand what the stop angel bead does....

Also, what holds the lead to the roof? gravity or clips etc? and shoudl I use mortor or lead mate?

Sorry to be a pain but Im no roofer as you can probably tell

 

[noseall]

lead needs to be fixed into the chase using lead wedges. the lead should be fixed in no more than 1.8m lengths. once wedged the chase needs to be pointed. the lead should have a 150mm upstand up the roof.

looking at your photo, you seem to have avoided all these requirements.

 

[pennelldj]

Thanks for ur post

Yes thats what I was thinking - its the old flashing that I have taken out ran basically the entire lenght of the roof which was very heavy - I therefore am trying to replace it correctly - the picture isnt my handywork thats what was in place

Could you suggest why they had two layers of leading? one nailed to a baton? and shoudl I just repalce with one layer?

Also dwhere the leading overlaps (no longer than 1.8m) doi they need to be welded together etc?

 

[noseall]

i don't have a clue why there are two layers of lead flashing.

you don't need to weld the overlaps, just make sure you have a minimum of 150-200mm lap.

also, dress the lead down into the contours of the roof tiles.

 

[pennelldj]

Great thanks for the reply, once last thing or maybe two...

ive read the use of clips to hold the flashing down to the roof but not sure they are suitbale or necessary for my type of roof, what are the tiles made of btw? (see pic)

lastly, what should I use to mortor or sealant and I havent a clue what ill use to cut the lead - could you give me a list of materials and tools I need, sorry to be a pain but ur help really is apprecuated, ill post tomorrow with the results, hopefully good ones!

Darren

 

[pennelldj]

Does anyone know if the lfashing has to run over the edge of the tiles and edging? not sure how to finish the edges

 

[diyisfree]

I concur with noseall regarding stainless steel lead wedges, but i have to say i use lead mate over standard mortar to seal.

 

[datarebal]

the flashing should be inserted into the brick joint at least 30mm and wedged with plugs made from off cutts of lead. point in either muck or lead sealant fit render stop bead covering the insertion point, repair render...However you will struggle sorting under the window sills..
The tiles look like Centurians and are concrete

 

[datarebal]

Nearly forgot..there is barely enough head lap on the existing flashing to tiles

 

[freddiemercurystwin]

http://www.leadsheetassociation.org.uk/html/1398.html
http://calder.sums2.ebiz.co.uk/media//CalderGTGLW.pdf