OK, I've probably gone mad

[Freddie]

If ever a stainless steel flue gets eaten away by wood smoke get your money and a load of compo aswell as this should never ever happen in a million years.

Sheepswool insulation is supposed to be the bees knees or dogs goonads, problem was they were maketing it on the basis that rockwool and fibreglass insulation was carcenagenic, but then the world health association de-classified rockwool and fibreglass insulation down to irritant as they could find no evidence that it was harmfull even in the longterm---so my agency plans for the West of Ireland went kaput

Even so sheepswool insulation will last up to 50 years is perfect for keeping warm, ask any sheep and you can install it in the nude without any protective equipment ( god i wish it had taken off )

But because it had the rug pulled from underneath it it isnt mass on mass produced and still works out expensive but not in the long term for your house but for a shed? then again if you had Masona's money --no problem

 

[masona]

still works out expensive but not in the long term for your house but for a shed? then again if you had Masona's money --no problem

I haven't got a shed

 

[2scoops0406]

Sorry, one last question, concerning the flashing. Having cut a hole in the wooden roof deck, do I also cut through the existing felt and attach the flashing on top of the exisitng felt, or should I lap the felt over the top edge and under the bottom edge of the flashing, or indeed, cut a circular hole in the felt, put the flue through this, and seal with the storm collar ?

I guess it depends on how hot the flue gets

BTW The roof is a simple single sloping (6 degree) wooden deck with a felt covering, in other words a bod standard shed roof.

 

[masona]

Cut a square hole less than 50mm all round if your flashing is square, then make a timber frame underneath to the edge of the square hole, rest the flashing on top of the felt bedded on with high temperature sealant then large washer + screws through the flashing to pick up the frame underneath. The outer flue will get warm but the flashing won't get warm or hot.

Also run a sealant on top of the roofing flashing where it meet the flue pipe and put some on the storm collar as well.

If you're still not sure I take a photo of mine.

 

[2scoops0406]

No, I think I understand that, do you think I should brush the slate chippings off the felt first?

 

[masona]

As long you don't damage the felt, if not, don't worry, put plenty of high temperature sealant under the roof flashing.