Slate Roof Deterioration

The following guideline is provided to assist in the repair replace decision making process.

Slate roof deterioration.

Calculate the number of damaged and missing slates. A professionally installed and well maintained slate roof generally doesn t require fastener replacement. Later when the building sagged settled or moved the framing pulls away from the chimney causing damage to the roofing slates and flashing and leading to leaks in this area. Finally the new copper valley is replaced and the roof will be performing well for future generations.

These determine the density and composition of the slate. Rain snow ice moisture is roof s enemy 1. Other commonly used modern building materials that depend on glue for their integrity such as laminates and wafer board will deteriorate long before the slate does. Older slate roofs that have been generally weakened are more affected by these elements than newer ones.

Another common source of slate roof damage around a chimney is wear and movement caused by flashing leaks and in freezing climates frost. It can damage its structure cause mildew rot decking and even damage the insulation. The usual decking to which slate tiles are nailed is solid wood 3 4 to 1 inch thick. Failure to recognize this problem and fix it can lead to rapid roof deterioration and complete slate loss.

Once the wood deck is exposed any deteriorated wood must be replaced. Consider the age and condition of the roof versus its expected serviceable life given the type of slate employed. How should information from the. Is the number less than about 20.

You can spot a sloped slate roof tile more easily from the ground. Check the stability proper functionality and correct installation of snow guards lightning protection systems and other safety devices. However excess moisture may lead to a more rapid deterioration of these materials and necessitate their replacement at some point. You can also check for gaps in the mortar joints along the ridge line.

Holes may form at the edge of the slate. Southern exposures are less important to the deterioration of slate roofs than with other types of roofs. Site conditions such as the roof pitch exposure to sun building moisture and ventilation and exposure to mechanical damage also affect slate life. If the tiles look to have a powdery surface this means the tile is deteriorating and you ll need to replace it.

This problem is known as delamination. Two courses of slate on either side must be removed in order for a valley to be properly replaced. The rate of slate deterioration on roofs depends on the source quarry and the depth from which the slates were cut. The longevity of a slate roof is only as good as its support structure.