The danger signs signs of deterioration on a roof almost always mean that the covering, be it slate or tile, has run the natural course of its life. Patching up here and there is literally no more than a stop-gap exercise, and the only sensible course is to re-tile the roof.
After all, your roof bears the brunt of the British weather, and is your home’s major protection against damage from sun, wind and rain. In its lifetime your roof will be drenched by more than 760,000 gallons of water weighing approximately 3,500 tons; baked by 90,000 hours of direct sunlight an subjected to at least 20,000 temperature changes, If your roof is worn out, the rest of your home is at risk. A defective roof covering that allows water to penetrate may well lead to problems with timber structure if neglected. Water penetration can also result in damaged ceilings and ruined decorations. Re-roofing is an excellent investment and its costs less than you may think.
How to check for danger signs
1 – Missing or loose slates or tiles let in rain which can cause costly damage to roof timbers and to other parts of the structure, apart from ruining your decorations. In addition, falling slates are particularly dangerous.
2 – Ridges normally need attention more often than the rest of the roof. If the ridge is in a poor state, the whole roof should be thoroughly checked.
3 – Valleys can be the first parts of a roof to leak. Valley welts and linings can fail and movement can create cracks and holes which are difficult to repair.
4 – Flashing to hips or where the roof joins an abutment or chimney, may be zinc, which can fail by corrosion or leakage at mortar joints, thus allowing water to penetrate. Defective flashings should be replaced with lead when you re-roof.
5 – Cement or tile fillets are cheaper than lead flashing and are often used at abutments. But cracks are often caused by movement and frost action can lead to water penetration.
6 – Copings can come loose and when deterioration is evident these should be re-bedded and re-pointed.
7 – Blocked gutters impede ‘ the flow of water from a roof.
8 – Crumbling chimney stacks and loose chimney pots are dangerous and should be re-bedded and re-pointed.
9 – Flaking tiles caused by frost action.