Before you purchase a property it is important to know exactly what you are taking on. Hidden flaws can result in enormous expense in the long run, and it’s important to assess these potential expenses before signing on the dotted line.
The two main issues in buying an older property are damp and vermin. Rising damp is the passage of water from the ground into the building, usually via the walls. This problem is usually evident in patches of flaking paintwork at the base of walls and is due to inadequate or absent damp-proofing. Make sure you check thoroughly at open inspections as the worst patch of damp is sure to be hidden behind a large chest of drawers.
Damp-proofing usually takes the form of a membrane or bituminous layer between brick courses or below a concrete slab that prevents water from climbing via capillary action up the masonry walls. Houses built before 1920 rarely have any damp course. It is possible to damp-proof existing walls through injection-feed and similar methods, but it can be extremely costly. Failure to do so will mean potential ongoing problems associated with damp, such as mould.
Rising damp may also be due to a timber floor structure being built too close to the natural ground. You can check this by inspecting whether the ground level outside the house is lower than the internal floor level or ideally by looking under the floor itself. It may be possible to fix this by lowering the ground level below and around the house.
Falling damp is less often discussed. It is evident in flaky patches at the tops of walls and on the ceiling. It indicates that there is a fault in the roof or guttering which results in water entering the house from above. It’s much easier to repair a roof than install a damp-proof course in an old stone wall, but it can still mean a significant outlay when you already have a substantial mortgage to pay off.
Termites are another major problem which is much more common in older homes due to the fact that termite prevention treatments were not available when they were built. If you’re lucky the previous owner will have kept records of termite treatments. Otherwise you will have to rely on an inspection of timber in the house, preferably by an expert, who will advise you on existing or potential recurrence of termite infestations. You then need to take into account the ongoing costs of termite treatment and whether the timber throughout the house will need to be replaced.
Other expensive items are plumbing and electrical. Watch out in older homes for a shared sewer or water supply that can be a hassle to separate.
In any case it’s always best to seek the advice of a professional who will conduct an inspection and prepare a report setting out in detail each area of concern and remedial action required. The Royal Australian Institute of Architects as well as the Master Builders Association offer building inspection services as do various private inspection companies.