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Options and life expectancy to fix a lead valley

I have a 7 metre lead roof valley which was fitted in the late 1970's. It was patched about 5 years ago (crack) and I have just noticed (due to wet upstairs walls) that it has two cracks in it. One about 9 inches and one about 4 inches.

At the start of the valley, it measures about 500mm going down to 250mm at the end. Just to give you an idea of size.

I guess the options range from a quick fix (paint over) right up to a complete re-lead job..... with many other options in between.

What I am really after is an indication of the different options available and also what sort of life expectancy I could get from each option.

Many thanks

4 Answers from MyBuilder Roofers

Best Answer

Hi there,

I'm a city and guilds qualified leadworker so obviously i'm slightly biased when reccomending alternatives.
For me the best valleys are lead, using a minimum of code 5. When installed correctly (i.e.Fixed and clipped to allow for expansion and retraction, with copper nails, treated with bitumus paint anywhere it is in contact with mortar and the correct underlay) it should last you for 40-50 years. Another good thing with lead is that you can weld any cracks or holes if they appear, providing it hasn't been painted :o(
Alternatives are fibre glass valleys, which are cheaper but only, in my opinion, offer 10-15 years before requiring some sort of repair. The other thing to consider is if something else were to go wrong elsewhere on your roof they offer very little resistance to damage and can perforate from being walked in/near and particularly if anything is dropped on them.
The Romans started using lead first and to this day, despite lots of other alternatives being tried, it still remains a fantastic material and well worth installing if you can afford it.

Hope this helps?

Many thanks,
Northampton Lead


Answered 10th Oct 2011

to renew the lead valley properly would give expected life of around 30 to 35 years minimum, repair the cracks and cover the existing lead in roof repair sealer would give approx. 5 to 10 years may be more


Answered 10th Oct 2011

There are other materials out there a lot cheaper than lead, ie epdm and glass fibre, but you cant beat replacing it with lead.
If youve had water leaks, then the lot will have to come up and replace the decking and any other rotten timbers.
Make sure the steps are right height, plus lengths of each step. done properly will last for years.
If building is listed, you will have to replace with lead.
Scrap lead is fetching good prices at present.


Answered 10th Oct 2011

You have several options open to you.
The best way to repair cracks in lead is to weld a patch over the crack. This will give the longest lasting repair available, but..... One has to take great care with a view to the risk of fire. ( though there is very little chance of this if you know what you are doing ) but a risk none the less.

Personally I have found in many years of working on roofs that once the flash band, mastic and tape gets introduced, things just go form bad to worse and you will be forever bodging every year or so until it can't be done anymore and you have no idea then where the leak actually stems from.

The most important point here is that if the lead has cracked it has been installed incorrectly, either over sized, under fixed or over fixed causing thermal movement that leaks to buckling and eventually a crack forming.

If you choose to get it replaced, when done properly it will not need doing again during the life of the roof. There is plenty of servicable lead around that is 100 years old plus.

Hope this helps


Answered 10th Oct 2011

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