Stained lead flashing

[laragh]

I need some advice on removing stains from lead flashing.

House is only built a year. Builders put in flashing above bay windows. I treated the lead with patination oil after they fitted it as they didn't seem overly concerned about doing it themselves.

Now the lead has streaks running down it and as it is at the front of the house it looks cat!!

The stains are from two sources I reckon- a white stain from the mortar where the lead is bedded into the joint in the wall and a green stain which must be some sort of reaction on the surface of the lead itself.

How can I clean this off and then treat to prevent it happening again?

 

[Nige F]

The green stain is leprachauns ****.........try cleaning with wire wool and re apply oil

 

[Pat Hougi]

Hi Laragh,

Yep the staining is caused by the mortar attacking the lead, everywhere I look in Ireland I see mortar directly applied to lead. This is very poor workmanship, not to mention the lack of patination oil.

Mortar should never be applied to lead directly, the lead should be treated with a bitumous paint first. A good lead worker will seal the lead first then bed into brickwork or retro fit the lead by cleaning out the joint and fitting in with a strong binding sealer, lead caulking can be bought from your Builders Providers.

Your problem is the mortar is always going to attack your lead, it will eventually eat through it and cause it to fail/become loose.

To get rid of the stain, lightly use stainless steel wire wool, rubbing down in one direction only, dont move in circles or scrub too hard, you effect the rolled grain of the lead.

wipe any pillings with soft rag, apply pat oil, again in one direction only.. p.s Dont apply when wet.

To really fix your problem, you could refit the lead, first off sealing the mortar contact point. Right now, it will last a hell of a long time before the mortar destroys it, prob 50-75 years, depending on the code of lead.

hope this helps.
Pat

 

[laragh]

Many thanks for the replies lads.

I'm off down the builders providers to get the wire wool.

Is there any sort of spray-on or paint-on sealer which could be used directly on the mortar joint above the lead. I don't really fancy refitting the lead again so anything that could be used to seal off the mortar and reduce the chance of the staining reoccurring would appeal to me!!