Leaky Twin Wall Flue Pipe?

[mjam82]

Hello,
My wife and I have had quite an ordeal with the kitchen extension we are building on our house. The issues came to light when we had our multifuel stove installed. After some heavy rain we woke one morning to find the stove covered in water. We later found that a large part of the problem was with the roof being built to the wrong pitch (it was designed to 15 degrees and ended up being less than 11). We've since asked the builders to leave the job (we were going round in circles), and had a roofing company in to increase the pitch to 17.5 degrees which cost £3k. We had some prolonged rain last night and found the stove covered in water again this morning. I had a feel in the ceiling and felt a bit wet up there but not enough to drench the stove and hearth. My partner and I believe most of the water is coming in from the twin walled flue (where it joins the fire). The stove is still to be commissioned for use as we paused that to get the roof fixed. There is no water inside the stove. We've got the roofing people coming back out to have a look at the small leak in the roof.

Can anyone advise about the twin wall leak? Is it common?

The company who installed the fire are coming out soon to have a look next week, but they are insistent that the outer wall of the twin wall system is a sealed unit so no water should be able to get in. I'm going to loosen the bottom band later to see if the is any water build up in there.

Thanks in advance,

Mark

 

[begreen]

It doesn't look like this pipe is sold in the US. A guess is that an improper, single-wall increaser is being used that is fitted inside of the stovepipe.
What is the stove's flue size requirement and what size is the stove pipe that is being used.

 

[stoveliker]

Is there a vertical seam on the pipe on top of the roof?
They are generally crimped (two sides folded over each other).
If so, that might pass as "sealed", but I'd put a bead of silicone on that seam.

ANother intrusion point can be the storm collar right where the pipe goes through the roof. But that depends a lot on the type of design.

 

[mjam82]

Hi Everybody,

Thanks for your replies. I did a more thorough inspection (pouring water down the roof from the bedroom windows). Looks like the leak is the roof right next to the opening for the flue. I've managed to pin point exactly where it's coming through. The roofing company are sending someone to have a look soon. Until then we have a bowl in position which has been catching rain water that gets in.

Thanks again,

Mark

 

[mjam82]

Is there a vertical seam on the pipe on top of the roof?
They are generally crimped (two sides folded over each other).
If so, that might pass as "sealed", but I'd put a bead of silicone on that seam.

ANother intrusion point can be the storm collar right where the pipe goes through the roof. But that depends a lot on the type of design.

The storm collar we have isnt fitted right down to the roof as the roof is sloped. I might look into getting a bigger collar for sloped roofs.

Thanks for the suggestion.

Mark

 

[begreen]

Good call on rain intrusion by stoveliker.

The storm collar we have isnt fitted right down to the roof as the roof is sloped.

Can you post a picture of this? The storm collar sits on top of the flashing and does not follow the roof slope typically.