Code 3: Code 3 is 1.32mm thick, and weighs 14.97 kg per square metre.
Code 4: Code 4 is 1.80mm thick, and weighs 20.41 kg per square metre.
Code 5: Code 5 is 2.24mm thick, and weighs 25.40 kg per square metre.
Code 3 & 4 are generally used for flashings and abutments, where a roof area joins brick or stonework. Code 5 is normally used on valleys, where two different angled roof slopes join. Although on special projects such as listed building thicker lead in these situations is often used.
Lead can come in codes (thicknesses) up to 8, which is 3.55mm thick. Thicker lead is used in areas with a slow drain-off period, such as flat roofs and box gutters.
Things to consider:
- ALWAYS wear gloves when handling lead.
- Treat your lead with Patination Oil to prevent white staining from occuring, and ensure it is kept DRY before doing so.
- Do not lay lead in more than 3m lengths without a join.
- When chasing out brick or stonework, do not point with mortar, use a specially designed lead sealant such as "Leadmate" to allow for expansion and contraction.
- The different codes or thicknesses of lead have different purposes. Be sure to buy the right thickness for your job, not just the cheapest option.
- Before use, keep your lead out of sight at all times, its high scrap value makes it an easy target for thiefs.
The scrap value of lead is currently very high, so if your doing some DIY replacements, weigh your old lead in to a scrap metal merchant. You may get up to 50% of the money you paid for new lead back!