Lead Repairs For The Competent Home Owner

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What Is Lead?

Lead is a naturally occurring metal found deep within the ground. It occurs in small amounts in or, along with other elements such as silver, zinc or copper. Even though it’s found in small amounts, there is an abundant supply of lead throughout the earth. Because it is widespread, easy to extract and easy to work with, lead has been used in a wide variety of products including Roof Flashings!

Why Is It On My Roof And What Does It Do

Lead sheet metal is one of the oldest materials used to water proof roofs. Lead is used on all aspects of roofing from pitched, flat, flashings, abutments, chimneys, roof valleys, valley gutters and parapet walls. Lead size is measured on its weight in lb per square foot. The most common lead weights are Code 3 (3lb per square foot) which is used for soaker’s. Code4 (4lb per square foot) which is used for flashings and roof valleys. Code5 or 6 (5-6lb per square foot) which is used for parapets, flat roofs, back gutters, valley gutters.

Lead has been waterproofing roofs for century’s and to date is still the best way of waterproofing you roof period. There have been many products released over the years for lead replacement but the ultimately lead is the best and has been proven over the years.

Lead does have its downfalls like any other non ferrous metals known to man. Being one of the most natural ferrous metals and due to the severe weather conditions the UK has, Lead will expand and contract when temperature rise and falls. The continuation of this procedure over the years will cause the lead to rise and split. This can help be prevented by laying the sheet lead in 2m (6ft 6″) lengths and no wider than 0.9m (3ft) and stepped, or if a step cannot be achieved have a welded expansion joint. Where the width of the lead meets a mop role is used to dress the lead over from both sides creating a welt and not allowing the water to get in. Both these procedures will allow the lead to move, help preventing it to split. see below

lead expansion joint

Expansion Joint

leadwork stepped

Lead work Stepped


Ultimately over many years of weathering the lead will inevitably split and will need replacing. Lead prices vary from month to month depending on its scrap value at that time as all metal is measured on its weight. Lead is an expensive metal and also requires a skilled tradesman to install it properly. Here is a list of the most common lead used on roofs and its weight and thickness. You can also download this (Lead Data Sheet) which will tell you all you need to know

  1. Code: 3 / Green
    Thickness: 1.32 mm / 0.052 inch
    Nominal weight: 15 kg/m2
  2. Code: 4 / Green
    Thickness: 1.8 mm / 0.071 inch
    Nominal weight: 20.4 kg/m2
  3. Code: 5 / Red
    Thickness: 2.24 mm / 0.088 inch
    Nominal weight: 25.4 kg/m2
  4. Code: 6 / Black
    Thickness: 2.65 mm / 0.104 inch
    Nominal weight: 30.1 kg/m

How Can I Repair My Split Lead Myself?

Every home owner in their lifetime will eventually get a leak in there roof related to the failure of a lead waterproofing. When it does happen it can be an expensive procedure due to access (scaffolding), the lead itself (price), and the severity of the repair (strip out valley etc.), and the labour to have it fixed. Well here at Layton Roofing we are showing you a D.I.Y procedure to cure your lead failures temporally until you can save your pennies for a proper fix. Here is the procedure below and most competent home owner could do with ease.

Step 1
Gain access to your damaged lead safely. This may require a hired scaffolding tower or even access of a secured ladder. Just make sure you or anyone doing the repair is safe. Please download both PDF files for Tower Safety and Ladder Safety.
Step 2
Tools required can be got from any local DIY merchant like, Homebase, B&Q, Screwfix ect.

 Step 3
Locate the damaged, split lead. You will notice the lead will be raises and a slight crack will be showing. Dress/Flatten the lead back down with your hammer. Once back to its original state use your 30mm nails and tack in the centre of the split line. This will hold both sides of the lead and stop if from raising again. If you don’t do this it will raise again and spit the flash band at a later date. See below.

Split Lead

Step 4
Before you go any further its advisable you have a fire extinguisher to hang, just in case!Also Check your insurance to see if you are covered for use of naked flames. If you are not you use at your own risk. Once the lead has now been secured with the nails. Not rub the lead with some kind of scour pad, or wire brush. This will take the white powdery coating (known as oxidation) off the top making the lead nice and shiny again. This will allow the bitumen backing to stick to the lead much better. Now stick a patch of flash band over the crack and heat up lightly with the heat gun. Don’t go to aggressive as the flash band only requires a little heat to soften the bitumen backing. It should look like this.

Flash band Repair

Step 5
Now once the flash band has been heated onto the damaged lead you can now paint it with the Acrypol paint. Make sure you give it a nice even spread and brush the fibres into the ridge of the flash band. Try and make your paint repair nice and neat. This is more for cosmetic reasons. Here is what the final finish should look like.

Acrypol Repair


Thank you for following our Blog and I hope this post has been informative and save you home owners you’re hard earned cash. If you think this procedure is beyond your personal capabilities and require a professional repair of full lead replacement then please contact Layton Roofing & Building Specialists now for free advice and no obligation quote.


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