I see your point Roger , why did you not just ask the insurer question?
Whilst lead is better for flat roofing than felt as it is less liable to damage it is still is laid in strips and the seams can be a source of water ingress if incorrectly laid .
Also lead is very nickable and you may find that your insurers are worried about the risk of theft and consequent damage, eg flooding as a result of you not noticing the theft until the rain comes in.... .
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I had a chat with my company insurance broker . I'm busy arranging my company cover for 2007 as well.
He advised that lead can have a tendency to crack , also water can get through our around apparently sound joints or flashing by capillary action and any flat roof can be damaged just by people walking on it .
What you have to remember also is that where lead flashings are pointed into brickwork it may be the pointing and not the lead that deteriorates allowing water ingress.
I see from your profile that you run a gallery - I would think that the last thing you or they would want is any chance of water damage.
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We had to have the lead flashings renewed on part of one of the chimneys last year because the lead had been damaged by the sun during a period of extremely warm weather.
Discovered eventually when water began coming in through a bedroom ceiling; the water was running down a joist and dripping onto the area over the bedroom.
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We had to have the lead flashings renewed on part of one of the chimneys last year because the lead had been damaged by the sun during a period of extremely warm weather.
More likely the mortar had crumbled away leaving a gap around the flashing. The melting point of lead is way too high for the sun to do much damage at this distance, even in sunny Southport, but nitric acid in rainwater may have helped the corrosion along.
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Roger, I could understand a requirement for an initial inspection to check roof condition and quality of workmanship, and decide from there. Are there other insurers you could try?
I have seen cracked lead flashings bodged up with bitumen paint or flashband, but I've not been on many lead sheet roofs.
This site has info. on leadwork and potential problems :
www.eastherts.gov.uk/guidnote/rainwater_goods/lead...m
"... premature failures of sheet lead in all situations are almost always due to oversizing and consequent thermal fatigue and stress failure (caused by the high coefficient of linear expansion of lead) and consequent buckling, creasing, ridging up and rippling and ultimately cracking and tearing, and incorrectly specified over fixing, that restricts or prevents thermal movement - expansion and contraction...
...The general principle is the thinner the lead - the smaller the piece..."
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Thank you for all your replies. I have decided to stay with my existing insurers as they do not have any problem with the relatively small amount of flat roof.
It appears that the insurance company have a blanket rule on any flat roof, irrespective of its construction. It appears that this rule also applies to a fibreglass covered roof, again another long life covering. Purely because of their condition of having the roof inspected annually (by a qualified builder or roofer - whatever they are!). The person who told me about this condition even put me on hold to have a word with their underwriter, but still insisted on their flat roof condition. I decided it was too onerous and declined to listen to any further conditions or find out what their quote was. As they say, there are plenty of other businesses out there wanting my insurance.
I do not know if it is just me, but I am finding insurance companies, in general, are now frequently asking for independant testing or certification on a wide range of items. What they are now insisting on as having to be independantly tested and maintained as a condition for insurance is now costing almost as much as their premium.
One company insisted on my compressor (used for about 2 hours per week) to be pressure tested annually at a cost of £185. However I could buy a new one for £400 and this would not need testing until 2 years old. The strange thing is my compressor tank has a British Standard wall thickness of 5mm, but the current Euro Standard only has 3mm wall thickness. Also I researched the number of people killed in the UK by compressors exploding - it has averaged just 4 people per year. When you consider the number of businesses have compressors, this is an incredibly small incidence. These figuers also include compressors that have been abused, damaged and bodged to keep them going. Personally I think this is a very good safety record for compressor manufacturers. Talk about insurance companies protecting their interest, rather than assessing the risk.
At the end of the day I still do not know how good my current insurers will be in the even of a claim. It has been over 12 years since I made a claim with another insurer (when a water pipe joint gave out in a hot summer), and that claim was handled very smoothly.
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Roger
I read frequently, but only post when I have something useful to say.
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>>More likely the mortar had crumbled away leaving a gap around the flashing.>>
No, it was the lead (replaced a while back for some reason or other) which had apparently contracted and expanded. The mortar was fine and, in fact, the slate roof was completely relaid a few years ago and new felt put in underneath.
The reason this had to be done was purely because, after more than 100 years, the nails were on their last legs. The slates were reused and only the nails and felt renewed in the traditional Victorian manner.
They don't build houses today like they used to do....:-)
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They don't build houses today like they used to do....:-)
I believe there was a "golden age" between about 1920 and 1950 when the timber used was still fully seasoned old growth, they used proper Rosemary tiles and had damp proofing, proper foundations, and cavity walls.
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After the erection of the late 19th Century properties in my town some of the streets in my area, where many of the houses were built in the 1920s and 1930s, contain properties that reveal imaginative use of designs and styles along with first class build quality.
Incidentally my Victoria property has cavity walls, which surprised a cavity wall insulation firm's representative after our energy supply company agreed to do the work FOC under a Government scheme...:-)
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>> They don't build houses today like they used to do....:-) I believe there was a "golden age" between about 1920 and 1950 ....., proper foundations, and cavity walls.
I have heard that said but not by me about my 1930s house.
Absolutely awful workmanship everywhere and solid walls except for one area of external wall which is single brick. Soil pipe wrong X 2, no roof lining etc. etc.
Just to make things worse I think they used concrete under the plaster so it is hell to fix anything on most of the walls.
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>> >> They don't build houses today like they used to do....:-) >> >> I believe there was a "golden age" between about 1920 and 1950 ....., proper foundations, and cavity walls. >> I have heard that said but not by me about my 1930s house.
No doubt there are bad ones, probably bad batches made by a single builder, but I think it stands as a generalisation: modern design with old-fashioned attitudes to weight of materials. My own 1930s house is built well where it needs to be, but they seem to have made a sharp distinction between "habitable" rooms (the kitchen) and "non-habitable" (the scullery) in terms of build quality. And it has a small lead roof too, still original and still watertight. I'd be annoyed if my insurer started demanding inspections.
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We had to have the lead flashings renewed on part of one of the chimneys last year because the lead had been damaged by the sun during a period of extremely warm weather.
My neighbour is a roofer with a lot of experience.
He advised me that a lead roof should be regularly treated with a paint specifically formulated for lead roofs in order to protect them from the sun.
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>>My neighbour is a roofer with a lot of experience.
He advised me that a lead roof should be regularly treated with a paint specifically formulated for lead roofs in order to protect them from the sun.
I have tried searching with Google and cannot find anything about a paint for lead roofing. The nearest thing I could find with anything about checking a flat roof and the expected life of lead was:
tinyurl.com/y8y7w7
Personally I believe this is a scaremongering claim, similar to asbestos cement.
The only technical document I found relating to the life expectancy of lead sheet was by Ben Travers, chairman of European Lead Sheet Industry Association.
tinyurl.com/t2tyr
?Correctly fitted lead sheet requires zero maintenance over its lifetime and can truly be used as a ?fit and forget? material, until the building is demolished.?
I rest my case, the insurance company did not know what it was talking about..
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Roger
I read frequently, but only post when I have something useful to say.
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>>Personally I believe this is a scaremongering claim, similar to asbestos cement.
I will try and ask him about it.
He has just recently completed a lead roof on his extension and it certainly has a finish on it..
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>>He has just recently completed a lead roof on his extension and it certainly has a finish on it..
Who would you prefer to believe, your neighbour in roofing or the Chairman of the European Lead Sheet Industry Association.
No doubt some company has devised a finish that can be applied to a lead roof, but that does not mean it has to be used. The finish might be to give the lead a distinctive decorative look. It is strange I could find nothing in my Google search.
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Roger
I read frequently, but only post when I have something useful to say.
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The neighbour who does the job every time Roger
The Chairman isn't going to 'do a Ratner' and say his material that he is selling is rubbish is he?
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Been doing a bit of Googling as well and it seems that "lead" flashings can be lead, copper or zinc and that protective paints and coverings are, in fact, available.
See:
tinyurl.com/wyns4
tinyurl.com/vsb7b (see page 12)
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>>He advised me that a lead roof should be regularly treated with a paint specifically formulated for lead roofs in order to protect them from the sun.>>
That's interesting. Unfortunately the roofer who did my work (and that of a neighbour), who I've known since school days, sadly passed away at a comparatively young age a few weeks ago, so I can't raise the subject with him.
When you find good workmen, or women come to that, it's hard to find someone equally as proficient and reliable.
My next door neighbour, for instance, is a Corgi registered plumber and heating "specialist".
I wouldn't let him within a mile of anything in my house, if you'll pardon the obvious mistake...:-)
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Being a Plumber in a former life I can confirm that lead will last indefinitely on a flat roof with a few provisos.
The method of jointing is crucial.
There are only two in my experience. One is lead burning which is simply welding together and was a trade in itself at one period when tanks were made in lead, and ornamental work was carried out particularly on Churches and sometimes coffins were lined with lead. This is carried out with a mini Oxy-acetylene torch with tiny nozzles. One of the most important rules is that the welding stick which is simply a cut off strip from the lead sheet and shave hooked clean is taken from the actual lead which is being laid on the roof. This is to ensure that expansion and contraction is exactly the same as the sheet.
I have seen work where they have used lead solder joints used as if they were wiping a joint. This will always crack due to the above.
The second method is double lock welts usually on raised strips of timber and this is an excellent method also. I know of no other methods.
The weight of sheet lead used varies for its use. If I recall correctly it used to be 5lb lead for flashings and 4lb for soakers which are pieces alongside the chimney which go under the actual flashings and under the tiles.
However I do remember in the late 50s helping in the removal of the lead roof which would have been there a couple of hundred years. The lead was according to my Boss 14lb lead and the value of it as scrap paid for its replacement in nural aluminium which again was done in double lock welts. Terrible stuff to work with? and again according to my Boss the only previous roof done in this material was Granby Hall in Leicester.
I?ve never heard before of the sun affecting lead and never heard of a finish on lead. When its new and is first put down it does shine brightly but like any other metal it oxidises with the weather and soon has a grey dusty appearance..
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>>never heard of a finish on lead>>
It seems you can get lead sheet with a finish/coating.
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When I used to work on site we were once about to demolish a big old factory. The roof had old glass rooflights for the top 12 foot of the roof, with lead sheet covering the ridge. We were going to have to erect a big scaffold to safely remove the lead and glass; but the weekend before, gypsies got on site and stole all the lead off the roof. How they managed to get a ton of lead off without someone falling through the glazed section must have been more luck than judgement!
I've got a photo somewhere (cant find it) taken by a steeplejack half way up the spire of St Marys Church in Chesterfield (the "Crooked Spire"). The spire is covered in lead sheet (32 tons of it) in a herringbone pattern and the photo shows a craftsmans name burned into the lead and a date of around 1850 or something...
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Very interesting that Rich.. The crooked spire is still standing then. I recall there was some talk about its safety some years ago. And whatever happened to that competition for the best plan to save the leaning tower of Piza some years ago.
The place I referred to was Alderwasley Hall near Whatstandwell, Cromford and not far from yourself.
Just had a look on Google and its now a special needs school. Looks a lot different now and may have a new roof on again. When I was there it was a Catholic school. The teachers were all Priests who had to be referred to as father by ourselves and the children came from all over the world.
The kitchen staff who used to make our brew up were all Southern Italian peasant type girls without a word of English.
We got the old lead down from the roof by chucking it over the parapet in sections and then straight to the scrap yard.
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If the correct quality of lead is used, a flat roof should last 90-100 years. No need for any coatings of any kind. 'Flat roof' is actually a misnomer, it should have a very slight fall.
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Lead roofing does not have an indefinite life, but it does have a very long one; a century at least before it begins to require attention.
Lead, as we know, is a very soft material. The interatomic bonding is weak, so it is easy to get the various atoms of lead to move relative to each other. It's very easy to bend or otherwise mechanically deform (there's that word again - see other thread) by hand. If we can do it by hand, then gravity can do the same thing. Lead suffers from a phenomenon called 'creep', which is the movement of lead atoms under a force. Gravity is a particularly noticeable such force. If you look at a sheet of lead cladding that has been on the side of a building for a century or three, it will be considerably thicker at the bottom than at the top.
In time, your lead sheet will creep off the roof - just like golden syrup. Like most chemical/physical activity this happens more quickly when the lead is warmed up - so worse on the south side of a building than the north.
A further problem of lead is - as previously mentioned - its thermal response. Moreover, compared to copper, lead sheeting is much thicker, so for a constant %age expansion, the linear expansion will be greater for the thicker sheets of lead than the thinner sheets of copper.
Interestingly, I too have heard that the scrap value of an old roof will pay for a new one. What I had heard, however, was that lead, gold and silver are commonly found within the same ores. Georgian and Victorian refining techniques were relatively poor, so that a significant quantity of precious metals remains within the old lead on buildings. Take the lead off, take out the gold, put the lead back. Make a profit.
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Moreover, compared to copper, lead sheeting is much thicker, so for a constant %age expansion, the linear expansion will be greater for the thicker sheets of lead than the thinner sheets of copper.
I don't follow, why does the thickness affect the linear expansion?
Number_Cruncher
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Mapmaker, interesting reply to this query of mine. If correctly fitted a leaded flat roof should last the life of the building. The problem areas should only be cracked joints, weak cemented flashing in points and impact damage.
However you do not state, like any other respondent, that a lead roof needs an annual inspection. I think any roof should have a periodic inspection, but as a general comment most roofs do not require an annual certified inspection, except felted flat roofs which are known to have only a short life expectancy.
I still believe this insurance company was trying to protect their own interest at the policyholders expense. This is something that is becoming ever more common and will probably come to motor insurance policies in the near future in the form of certified maintenance to manufacturers and Department of Transport/ VOSA regulations.
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Roger
I read frequently, but only post when I have something useful to say.
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