There are common defects with secondary roof coverings (felt under the roof tiles) that often go unnoticed as it is difficult to identify and if left for long enough can cause significant damage that can be very costly to repair. One location where damage can occur is at the eaves of the roof. This can be seen most easily on bungalows where the roof tiles meet the gutters. Just under the last row of tiles, the felt is purposely dressed into the gutters so that any rainwater that may bypass the roof covering can then drip into the gutter. The felt in this location is exposed to UV rays and hot and cold temperatures which eventually causes the felt to deteriorate as seen in the picture below
One location where damage can occur is at the eaves of the roof. This can be seen most easily on bungalows where the roof tiles meet the gutters. Just under the last row of tiles, the felt is purposely dressed into the gutters so that any rainwater that may bypass the roof covering can then drip into the gutter. The felt in this location is exposed to UV rays and hot and cold temperatures which eventually causes the felt to deteriorate as seen in the picture below.
Another way of identifying this defect where you cannot access the eaves as easily as with a bungalow is by observing the fascia boards. If you notice stains on the fascia board in the form of drip marks, this is usually a good indicator that the felt has deteriorated and rainwater is dripping onto the fascia board instead of into the gutter, as seen in the picture below.
When this defect occurs it can lead to dampness internally that is most commonly found at the junction of the wall and ceiling. In more serious cases this can lead to rot in the roofing timbers, usually the ends of the rafters and the wall plate. To prevent this from happening, an eaves tray or eaves protector should be installed. An eaves tray is constructed of thick plastic and designed to bridge the rafters, provide support for the roofing felt and ensure rainwater drains away correctly. Below is an example of an eaves tray.
Roofing contractors who are undertaking this work should be qualified in asbestos awareness as the roofing felt can contain asbestos.
