Roof Covering Defects

Weak points can be created where services pass through the covering.

Roof covering defects.

Damaged missing and slipped slates. Flat roof defect 2 blistering. Defects in pitched roofs normally caused by 3 main factors. Slate coverings to older roofs were secured with steel nails which are susceptible to corrosion known as nail rot or nail sickness.

Build up of moss. Bubble like or long thin raised areas on the roof are called blisters. Check for any damaged missing and slipped slates. Typically before 1890 nineteenth century roofs often contained narrow rafters.

Many of the problems associated with felt coverings to flat roofs stem from poor workmanship. Installing flat roof coverings be they felt asphalt or sheet metal is a specialised job. Even small amounts of trapped moisture can result in your flat roof membrane detaching from the layer below and cause roof blisters. One of the most common problems we see with metal roofs is improper repair.

Note or take photographs of. The perimeters are vulnerable even if the roof covering itself causes no problems. Diy felt jobs are the biggest culprit and are simply storing up problems for the future. Damage as a result of making.

Example topics discussed in our building roofing articles include asphalt roof failures including thermal splitting and other defects causes and types of asphalt shingle roof leaks shingle blow offs and wind damage shingle cracks blisters stains thermal splitting and other damage fire retardant plywood roof sheathing defects. Damage can be caused by workers operating in the area. Warm air rising from within a property reaches the underside of the roof covering cools and deposits moisture on the underside of the slates saturating the nail heads. Blisters are the most common roofing problem.

People go up with caulking and plastic roof cement and improper materials that are in no way intended for that purpose harriman says. Check for poor cement pointing and in particular for damaged or missing lead or cement flashings. This is the most common roofing problem and it tends to get worse during the day when the heat of the sun causes the trapped moisture to expand. They occur when a gas usually water vapor is trapped within the roofing system either between the plies or between the plies and the insulation.

Using materials that are not intended for application on specific roof types can result in permanent damage to the roof. Poor designs found in pitched roofs inadequately sized members. This slate roofing photo series shows all kinds of roofing slate defects. Pitched roof coverings roof defects 1.

Poor design damp penetration and failure of the roof covering which we sometimes see in out house surveys in london.