Wood burner / chimney leak?

paperclap

Hi all,

Heavy-ish, but persistent rain here in the South East right now. Have noticed a ring of rust surrounding the glue on my woodburner for some time, but hadn’t thought anything of it. Now have seen this big ole damp patch right now, as it’s raining.

Check up inside the flue, and rainwater is coming down the flue.

Recently had the lead replaced around our chimney. While the roofers were up there, asked them to check if the flaunching and cowl were okay. They said it was. A few hairline cracks in the flaunching, but nothing that would cause any problems. Though, whether they actually looked, I don’t know (they were there to do the lead, after all).

What could be causing this?!

Our chimney is on the right. Shows our cowl and a glimpse of the flaunching.

jonnydeppiwish!

If it’s driving wind and at the right angle, it will let water in.  I have the same on a SW facing flue

mexican_dave

Yes, it could be the direction of driving rain is coming from. How long have you lived in this property?

stuart45

If the liner has been installed correctly and goes through a closure plate into the pot, the rain can only get in from the top of the pot, and cracks in the flaunching shouldn't allow moisture into the liner.

paperclap

I do infact have a SW facing chimney.

However, I under the issues with roof tiles being potentially prone to letting water in when SW or what have you... but a chimney, well, it shouldn't really matter on it's orientation, should it? For all intents and purposes, a flue inside the chimney is the same whatever way you (literally) spin it.

Stuart45, thank you. I don't know a great deal about the construction of these, so forgive me. A closure plate is a metal plate that caps off the underside of the chimney (visible inside the house), and above the wood burner, correct? We've got that installed.

stuart45

A closure plate is used at the top as well as the bottom. At the top the end of the liner goes through the plate. The pot goes over the liner and sits on the plate. You fill in with sand/cement inside the pot between the liner and pot.
Outside the pot you build up a few courses of brickwork and fill in with sand/cement and flaunch the top.

mexican_dave

The wind direction can come into play here, since although both the chimney and cowl in the photo present equally to whatever wind direction, this chimney is not central, not on the ridge. But instead sits on one side of the pitched roof, so when the wind blows there is a pressure difference, which could push rain into the pot/flue. Refer to:
https://www.marley.co.uk/support/latest/weather-resistance-wind