Lead staining on new chimney

[cardiffrob]

I've just had a new chimney stack put up and there is a lead sheet half way down that separated the top and bottom of the chimney with a sheet and a formed collar within it. The lead has, within a month, started to take on a garish yellow stain that is now marking the brickwork. There was no oil applied during the build and they didn't add any sealant to either the edges or the flat sheet section.
Any suggestions as to what I can do? Also, what are the long-term ramifications of this staining?

Thanks

Rob

 

[mike os]

You could go up and get some patination oil on it... no long term issue, just unsightly

 

[roofman]

I've just had a new chimney stack put up and there is a lead sheet half way down that separated the top and bottom of the chimney with a sheet and a formed collar within it. The lead has, within a month, started to take on a garish yellow stain that is now marking the brickwork. There was no oil applied during the build and they didn't add any sealant to either the edges or the flat sheet section.
Any suggestions as to what I can do? Also, what are the long-term ramifications of this staining?

Thanks

Rob

is the lead sheet exposed to chimney smoke...depending what your burning sometimes can have a chemical reaction. a pic would help

 

[cardiffrob]

Thanks. I had a crack at getting the 'yellow' off with a Scotchbrite pad and then adding Pat oil but there is still a lot of yellow crud at the joint with the mortar. I'll try for a close-up pic tomorrow. I haven't got my log burner in there yet. Only got the floor screed down today.

 

[cumbriasteve]

Must be an optical illusion or else they are building that chimney from the top down , it sure looks like it is sitting on the roof with nothing below it.

 

[brightspark]

Must be an optical illusion or else they are building that chimney from the top down , it sure looks like it is sitting on the roof with nothing below it.

u should have gone to specsavers itlook ok to me

 

[colnerov]

Must be an optical illusion or else they are building that chimney from the top down , it sure looks like it is sitting on the roof with nothing below it.

Oh good, I thought it was just me.

 

[cumbriasteve]

u should have gone to specsavers itlook ok to me

I do go to Specsavers...your turn perhaps ...unless it's the home brew

 

[jonathan dempsey]

The yellow is probably creosote leaching. If the chimney liner isn’t perfect then some fuels with heavy sulphur content build up soot and tar. The leaching is probably due to this residue sitting on the lead pan and washing out with rain. Curing it is not just a question of scrubbing it off I’m afraid

 

[fixerupper]

I don't think the chimney has ever been used .....Jeff....

 

[jonathan dempsey]

Well thats weird. It could of course be staining coming from the cement/sand. But Somehow I have a feeling this is gonna be one of those things. And when the answer presents itself. We will all go “Oh yeah"

 

[fixerupper]

I think it must be something in the mortar mix , be good to see a close up photo ....jeff

 

[Paul99]

I think it must be something in the mortar mix , be good to see a close up photo ....jeff

Yes that's my guess. The builder didn't mix frost proofer or water proofer in with normal plasticiser did they? or use either with lime to the mix?

 

[roofman]

Its more than likely condensation on the top of the lead and bleeding the sulphates from the sand or mortar...i bet once the fire is lit the staining will go...Sometimes depending what part of the country you live dictates what sand you build with,I done a load of work down Margate once and you could,nt buy red sand only yellow which was very corse and this impacted the final pointing on ridges ect with regards to colour bleeding.The most stable mix ive ever used was Tilcon (think that was it was called) coloured mortar,nice and stable from start to finnish with almost zero fading or dis-colouration.

 

[cardiffrob]

It took a while to get a working camera. Hopefully this shows it well enough.

 

[roofman]

Thats a better pic...its oxides from the iron and metal content used in the fireing process in the bricks. Looking at the tear in the lead too on that corner it looks like the backbox was made from code 3 lead (roof police in the house..LOL)

 

[cardiffrob]

You'd have thought that they'd have got it right by the 3rd attempt at making it waterproof!

Thanks for the info. Should I wire brush it off and Pat oil it or just leave it?

 

[roofman]

You'd have thought that they'd have got it right by the 3rd attempt at making it waterproof!

Thanks for the info. Should I wire brush it off and Pat oil it or just leave it?

ide leave it mate or it will keep doin your head in every time it comes back...once the lead has a few moons under its belt the normal patina will take over