A recent Homebuyer Report carried out on a home in Croydon revealed a classic example of a problematic flat roof.
Felt coverings to flat roofs typially have poor durability and often require frequent patch repairs with a complete overhaul required every 10 years or so. (read more about flat roofs)
On this property the flat roof to the ground floor rear extension of the flat was not part of the original construction of the house.
The abutment of the flat roof to the external wall of the building had been dressed up in mineralised felt, which is normal building practice. However, it is recommended that when the roof is recovered a detail is adopted which will allow the roof to move independently of the external wall of the building, incorporating a lead flashing as an improvement.
The single-storey flat roof is no longer serviceable due to ageing, and it is necessary to effect a full recovering of the roof, to improve the ventilation to the flat roof, and to repair any defects to the structure below the felt should these be revealed.
The surveyor was able to gain access to the flat roof using a ladder, and a detailed inspection was possible. The roof was continuous with that of the property next door and there will be a need to coordinate repairs. Some agreement may be required with the adjoining owner as to the specification and the timing of the roof repairs. At this stage it was essential to obtain a quotation for budget purposes.
Normally in surveys such as this many surveyors will refer to parts of the roof which cannot be inspected.
To avoid this our surveyors carry sectional poles upon which they place a small video camera. While this is not an ideal way to inspect it does allow surveyors to see the flat roof above the extension. This was a felt covered roof which although functional for the time being was a little disappointing. At the margins of the roof there was a double lap recovering which covers part of the top of the roof and part of the facing structure below. The surveyor noted that these areas had lifted slightly in part which may indicate that the roof installation was not of the highest quality, given that it was relatively new.
Access to the upper flat felt roof was awkward and required scaffolding. It would be very difficult for the new occupier to monitor the roof for further defects. The surveyor raised an immediate cause for concern in terms of potential for leakage of the roof.
It is always prudent to check if the contractor has provided an insurance backed guarantee for the works, and if this is transferable to the new buyer on the purchase of the house. While house insurance cover is likely to accept liability for any damage owing to water leakage in the future, insurers will not pay for the cause of any defect, only the damage which has occurred because of it.
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