BLM Lead Pointing Sealant is specifically designed for pointing joints between Lead and masonry or brickwork; a low modular, non-corrosive, neutral cure silicone sealant which can be applied easily using a mastic gun.
BLM Lead Pointing Sealant provides a simple solution to this problem; a low modular, non-corrosive, neutral cure silicone sealant which can be applied easily using a mastic gun.
The most common reason for water penetration at an abutment is failure of the mortar used in pointing the joint between the Lead and brickwork or masonry. This is due to the inability of the mortar to expand and contract at the same rate as the Lead during temperature changes. In extreme cases, the pointing will crack and allow water to penetrate the joint and subsequently cause dampness within the building fabric.
Ensure the joint is dry and free from debris and dust before applying
The nozzle on the sealant tube can be cut to suit the width of the joint to be filled
Minimum depth of sealant not less than 25mm
For chase heights of 6mm - 18mm use BLM Hall Clips to secure the Lead flashings in place
For chase heights over 18mm use Hall Clip Plus or turn up the Lead flashing at the back of the chase and screw to the wall using stainless steel screws
Flashing lengths should not exceed 1.5 metres
Ensures long-term protection against water penetration
Coloured grey to blend in with the Lead work
Unique formula allows the Lead to expand and contract without cracking
Fast and easy to apply
Average tack free time is approximately 30 minutes
Available in 310ml tubes
Lead Pointing Sealant ‘How To’ Video Transcription
Below is a transcription of a video shot by BLM with Tim Fuge, Young Leadworker of the Year 2016, on the correct way to use Lead Pointing Sealant to point Lead Flashing.
Hi, my name is Tim Fuge and we're here at the LSTA Training Centre in Kent to bring you the latest BLM guide to using Lead Pointing Sealant.
Why Use Lead Pointing Sealant on Lead Flashing
The most common reason for water penetration at flashing joint is the failure of the mortar used in the joint between the Lead and the brickwork or masonry. This is due to the inability of the mortar to expand and contract at the same rate and the lead during temperature changes. In extreme cases, the pointing will crack and allow water to penetrate the joint, and subsequently cause dampness with the building fabric.
The simple solution to this problem is BLM Lead Pointing Sealant, low modular, non-corrosive, neutral cure, silicon sealant which can be applied easily with a mastic gun. Its unique formula allows the Lead to expand and contract without cracking, ensuring long term protection against water penetration. It's coloured grey to blend in with the Leadwork and is fast and easy to apply. When raking out an existing joint, it is important to remove all the mortar to a depth of at least 25mm. Ensure the joint is clean, dry, and free from cement, dust and loose debris that may affect adhesion. The joint should be at least 6mm wide to allow BLM Hall Clips to be inserted to hold the Lead Flashing in place. It is important to remember that no flashing length should exceed 1.5 meters.
How to apply Lead Pointing Sealant to Lead Flashing
Cut the sealant tube nozzle to suit the width of the chase. Insert the sealant into the chase. The face of the sealant can be smoothed using a wet pointing tool. Tack free time is approximately 30 minutes, depending on the ambient temperature. BLM Lead Pointing Sealant is available in 310ml tubes and is recommended as a suitable alternative to mortar.
For further information, or to download a technical or health and safety data sheet, then please visit britishlead.co.uk.
Thanks for watching, and don't forget to check out more videos from BLM on YouTube, or via the free BLM app available to download from your app store.
To learn more best practices when it comes to leadwork use the links below to download the BLM app
A Product Data Sheet and H&S Data Sheet providing handling, use and storage advice, as well as Basic Fitting Guides for Fixing Flashings could be found on the downloads below: