Lead work & cavity bridging (with pics)

[YellowBeef]

Looking for some advice please for our 1930s bay window which has seen better days. The timber (4x2) underneath the window is rotten, which I’ll replace with 6x2 to allow for air gap and 100 of pir foam insulation. Not sure what to do about the lead tray though? Needs replacing, as do the windows. Is lead still used under windows or just the tiles on the outside? Anything better I could use?
Also the cavity on the right covered with slate and plaster, which is a cold bridge as you can see from the mould on the paint work above. What’s best to replace this with to avoid this issue please?
See pictures attached.

 

[Bonni]

Not something I've come across but the lead idea is usually done like that (ish) on dormer windows. With it being made out of wood, probably why.

I've built bay windows but from the ground up. Now-a-days, we either use PVC cavity closures due to not returning inner brickwork or ruberoid dpc if returning the inner brickwork (just whichever is specified on plan).

 

[^woody^]

Full-fill the timber frame, no need for an air cavity. Vapour barrier internally before plasterboarding.

Yes lead is still the best thing for the flashing, but it doesn't need to be under the complete cill, just the first 30mm or so.

10mm insulation (polystyrene or PIR) up the reveal to stop the cold bridge. DPC and insulation or expanding foam to close the cavity.

Sort out the lack of frame fixing to the reveal

 

[noseall]

Looking for some advice

20160107_085741 (3)

• noseall
• 24 Apr 2016

Bow2

• noseall
• 24 Apr 2016

Bow3

• noseall
• 24 Apr 2016

Bow5

• noseall
• 24 Apr 2016

Bow4

• noseall
• 24 Apr 2016

Bow6

• noseall
• 24 Apr 2016