Whether stone or brick, water will penetrate and absorb into the wall which can then lead to dampness progressing down into the inside of the building. With the wall exposed to the weather conditions the stone or brick will eventually deteriorate and break down. By installing a lead capping, you will eliminate both issues and protect the wall for many years.
No one like to look at an old weather wall especially if it is showing signs of wear and tear. Installing a lead capping not only protects the wall by also improves the looks of the wall too. By covering up the broken/cracked stone and leaving a smooth grey finish.
Lead is known to last well over 50 years if installed correctly, sometimes lasting over 100 years which outlasts any man-made alternative.
Lead is extremely durable and resistant to the weather and allthe other environmental factors, therefore, by using a lead capping you will protect the wall/parapet for a very long time.
If a wall is already showing signs of wear and tear, then installing a lead capping is most cost-effective solution. Repairing stones is considerably more expensive than installing a lead capping, and if left uncovered the new stone will eventually deteriorate too. If covered with lead then you will most likely get away without any repair work and the wall will be protected from any further damage, will reduces future spending in repairs in the years to come.
If the lead is over fixed then the movement of the lead will be restricted which will cause the lead to split and fail. If the lead is under fixed then the lead may pull out of the fixing causing it to move out. of position and potentially falling off the roof/wall.
If the incorrect jointing method is used, then not only might the leads movement be restricted causing it to split but water will most likely penetrate the joint
If the lead capping is installed is oversized lengths then the lead will fail due to thermal movement being restricted, the same holds true if the wrong code/thickness of lead is used also.
If the lead is fixed with an incompatible metal, then the lead will react with the fixing causing it to corrode which will eventually lead to the fixing failing.