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Welcome to the Lead Page...... Here are some photos of our recent Lead work. Plus Lead detail work below.....
If you would like to see more photos of our Lead work, Lead down pipes and Lead hoppers then please follow this link: Lead Gallery Facts About Lead 1. Malleability. Lead is the softest of the common metals and its refined form is very malleable and capable of being shaped with ease at ambient temperatures. Generally the need for periodic softening or annealing is not necessary since Lead does not appreciably work-harden. Lead can be readily manipulated with hand tools and by the technique of bossing, can be worked into the most complicated of shapes or dressed to fit many types of deeply profiled tiles used for roofing. 2. Fatigue Resistance. Lead is a metal of low strength but in its use for building applications, provision is made for this by sizing and fixing the individual pieces of Lead so that the risk of fatigue cracking is minimised. Another factor that affects the strength of Lead is its chemical composition. This is strictly controlled by BSEN 12588:1999 to include very small amounts of other metals that control the grain structure and make the Lead more resistant to thermal fatigue without affecting malleability. 3. Creep Resistance. Creep is the tendency of metals to stretch slowly in the course of time under sustained loading. However, experience has shown that significant creep will not occur with external Lead work if the pieces are sized correctly. 4. Durability and Thickness. Proof of the durability of Lead can be seen on cathedrals, churches, historic buildings and countless ordinary dwellings throughout the UK. Lead is extremely resistant to corrosion by the atmosphere in town, country and coastal areas and generally speaking, the thinnest Lead will outlast almost any building so far as atmospheric corrosion is concerned. Other factors which have to be taken into account when specifying thickness are allowances for bossing or dressing into deep profiles such as over glazing bars or tiles, vulnerability to wind uplift, possibly mechanical wear due to foot traffic (eg during maintenance) and the quality of the building. On most historic buildings and in positions of extreme exposure, thicker codes are normally specified. 5. Thermal Movement. Most Lead used in building is fixed externally and thus subjected to considerable changes in temperature. The coefficient of linear expansion for Lead is 0.0000297 for 1c and it would be quite common in the summer, where the Lead is heated by the sun, for it to vary in temperature daily by 50c therefore, a 2m length of Lead sheet could increase in length by 2m x 50 x 0.0000297, about 3mm. 6. Contact With Other Metals. Experiences have shown that Lead can be used in contact with another metal such as Copper, Zinc, Iron, Aluminium and Stainless Stel with-out risk of significant bi-metallic corrosion. In some cases, this appears to contradict the electro-chemical series which compares the potential rates at which metals corrode. However, no problems arise in the traditional use of Copper nails and clips as fixings for Lead and there is wide experience of satisfactory use of Lead flashings with Aluminium glazing bars. 7. Resistance to Corrosion - Lichens and Moss. Slow corrosion of Lead by dilute organic acids can arise where there is Lichen or Moss growth on slated or tiled roofs. The rainwater picks up organic acid from the growth and where it runs on to the Lead it gradually forms grooves that in time can penetrate through the Lead covering. Any drip-off points, such as along a slated roof over gutter lining, the acidic rainwater causes circular corrosion areas below the drip-off points. After many years, this corrosion can penetrate through the Lead. The rate of corrosion on Lead is very slow and is not usually a problem in domestic flashing applications. In situations where areas of roof covered by Lichen discharge into Lead lined gutters, the problem can be avoided by fitting Lead sheet sacrificial flashings. Or phone us on:- 07970 457830  Entire contents of this web-site belong to Ian Cox Roofing Limited and must not be copied with-out written consent. If you require any technical information please do not hesitate to contact us. |
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