Problems With Chinese Slate Roof Tiles

For many years bangor blue slates from wales were the most popular and widely available roofing slates in ireland.

Problems with chinese slate roof tiles.

S of chinese slates above and loaded at the railway station below bove many sla leach during acz sts wang w varies as a result of the slate dressing which can lead to stress fractures. The fundamental weakness such products exhibit is a lack of durability cracking and disintegration and dimensional instability warping and cupping in the presence of water. Nowadays around 75 of global production originates from spain so it is hardly surprising that spanish slates present a tempting alternative to those building their own home. Although slate quarrying was not common in the united states until the latter half of the nineteenth century slate roofing is known to have been used prior to the revolution.

Possibly the most damning indictment of variation in chi nese slate is the con tent of carbonate minerals especially calcite caco. Synthetic slate also known as composite includes made of the features that have made actual slate a popular roofing material but it attempts to cut back on some of the drawbacks. However like with most materials these patterns paints and design can begin to fade over time especially when exposed to harsh weather conditions. Archeological excavations at jamestown virginia have unearthed roofing slate in strata dating from 1625 1650 and 1640 1670.

However in cases where the slate is sub standard they can react causing major damage and failure on the roof after only a few years. When this can be detected in a number of slates across a roof it is termed nail sickness. A reclaim yard may have enough to do the job but they could be a mixture from different roofs even different locations and so do not quite match on the roof. 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.

A common problem that occurs when using reclaimed materials is that there are simply not enough of the particular tile or slate available from a single batch to complete a roof. Wood paper or perlite reinforced portland cement slate and shake products are not suitable for use as long term roof coverings where they are expected to get wet. Another common source of slate roof damage around a chimney is wear and movement caused by flashing leaks and in freezing climates frost. The following list will highlight some of the pros and cons related to this product.

In the case of good quality slate these pyrites should not be an issue remaining dormant and unreactive.