WHAT ARE THE MOST COMMON CAUSES OF A LEAKING ROOF?
Leaks in roof are usually caused by one of three reasons:
CRACKED TILES OR SLATES
Roof tiles / slates are often cracked by contractors when work is carried out on the roof such as the installation of solar panels or cleaning windows.
Roof tiles / slates should not be walked on, and rarely survive this happening - if left,even a hairline crack will permit the ingress of water.
CRACKED POINTING AT VERGES
Many roofs have cement verges. These will eventually crack allowing water into the property.
All new build properties, and many refurbishment projects, use plastic verges which are a 'fit and forget' product that seals verges permanently against the effects on water ingress.
Lead flashings, particuarly on older properties, are chased into the wall, with the gap, or 'chase', then filled with mortar. The expansion and contraction of the lead as it warms up in the sun and then cools at night, leads to mortar failure which in turn leads to water entering the property.
The use of silicone sealants is little better than cement,as these products will rarely last for more than a year under these conditions.
The solution is the use of a proper Lead Sealant which is specifically designed for this purpose and will provide many years of leak free service!