Pitched roofs - what are the problems?

We’ve talked about the benefits of commissioning an RICS Homebuyer’s Report, from identifying issues with dry rot to finding out if you have a problem with red ash. Roofs can provide another house buying headache which may be avoided with a Homebuyer’s Report.

There are three main factors that can cause problems with a pitched roof. These are poor design, damp penetration or a failure of the roof covering.

Surveying the scene

During a Homebuyer’s survey, an RICS qualified surveyor will visually inspect the roof space to ascertain the structure. Houses built before 1890 often suffer from inadequately sized rafters. These can struggle to cope with the weight of the roof covering. If a new roof is put on an old building, heavier roof coverings are often used and will cause the same overload problems. The survey will reveal when a roof is too heavy a load and the surveyor will advise reinforcing it.

Damp readings are routinely taken throughout the survey as damp ingress is not always visible. If there is no obvious failing of the roof covering, it may be caused by condensation which occurs due to inadequate ventilation. This is very common when a property has had a retrofitted loft extension. An early indication of condensation is a white residue on the roof timbers.

One size of guttering does not fit all

Your surveyor will be looking at a number of other roof related issues too. Gutters must be the appropriate size for the roof. Calculation for the right measurement can be made based on the roof size and average rainfall for the area. Some roof coverings can shed more water at a relatively low pitch but some roofs need a steep pitch. The tiles need to overlap enough to prevent water getting in but too much overlap means there is too much weight on the structure. This is particularly common for roofs that were retrofitted in the 1970s and 80s.

In addition, your surveyor will be looking out for nail rot, moss build up, frost damage, cracked cement fillets, improper felt installation and inadequate or damaged flashing.

Do any of these problems sound familiar? Did you have problems with your roof after you moved in or were you put off a house purchase by the state of the roof? We’d love to hear from you about your experiences.