This is the next in our building surveying blog looking at the major items of defect within a building survey report. This building survey blog deals with roofs.
Often roofs are the single biggest, or one of the single biggest, identified in a building survey. The costs are largely accounted for by the replacement of the materials themselves but often the cost of access which will generally be by way of scaffold, which on a normal three bedroom Victorian terraced house can by anywhere from £2,000-£7,000 plus vat or £30.00 per sq m.
The access provision is often a high proportion of the overall cost. It is often therefore advisable to group works, so for example undertake chimney works and parapet works when a scaffolding is in situ. This means that the client is gaining economies.
There are three principal roof coverings that are commonly used for pitched roofs in the UK, these being clay tiles, concrete tiles (interlocking or plain) and slate. There are of course many other types of pitched roof covering that are possible, albeit these are the main three categories that are largely encountered during building surveys.
A building surveyor will be looking at the condition of the roof very closely during a building survey report and looking for both the condition of the material forming the roof, as well as the ridge tiles, verge, overhang and fundamentally the roof structure.
One common failure in say Victorian terraced houses is replacing the original, most likely slate covering, with an interlocking concrete tile as this is a much cheaper alternative, however the interlocking concrete tile is roughly twice the weight of the slate alternative. It is often therefore necessary to strengthen the roof frame to take this additional dead load, however this is often not undertaken. This can lead to issues of overloading and stressing on the roof frame, most particularly where the purlins become overburdened and require extra strutting.
Issues with slate roofs often involve the perishing of the material itself and the fixing nails an affect that is known as nail sickness, where the fixing nails corrode. This is often shown by slipped slates, or what are known as tingles which are metallic strips holding the slate in place. If a building surveyor notes that there are many slipped slates or numerous tingles, it can often be a sign that the roof may require renewal.
Building surveys undertaken by RES Property Surveyors have detailed sections in respect of roofs, with inspections both externally and internally of the roof covering and roof void respectively. Our building surveyors will be very happy to undertake any building survey matters or discuss any concerns by way of building survey reports or specific roof defects report.
If a client has a specific concern in respect of the roof then RES can undertake a defect report dealing with this item only to involve an assessment of the condition, remedial works and costings. Our building surveyors use camera poles up to 10 metres to get full vies of the roof.