Can you tell whether you are buying a timber frame or brick house? Take a look at the photo.
Many modern timber frame houses have brick outer skins that make it very difficult for the untrained eye to tell the difference. This skin is not load bearing, but is the protective jacket for the inner timber frame. Other finishes on older timber frame homes, such as panels of wattle and daub, clap board or tile hanging tend to show all or part of the timber frame.
At a recent Chartered Surveyors seminar, part of our Continious Professional Development programme held at Woodward Chartered Surveyors London Office, Director Stephen Cornish FRIC reviewed the history of timber frame construction in the UK and structural failings or defects that surveyors need to be aware of when undertaking a building survey.
As a structural material, wood is strong in both compression and tension, unlike concrete blocks, that require reinforcement under tension load. Each period of building reflects different uses of timber frame and different materials, therefore different potential defects.
Modern timber buildings are fast to erect, strong and when done properly, use soft wood pressurised with preservative for longer life. Nonetheless, poor on site storage before build or failure to seal the important vapour barrier when making connections for services such as electric and plumbing, can have severe consequences with warped, bowed or damaged structural timbers at a later date. By contrast older timber buildings are generaly made of hard wood, that is known to last hundreds of years if looked after.
The building surveyor of a modern timber frame home can not easily see (or sometimes at all) into the cavity wall to ascertain the condition of the wood. Nonetheless their home buyer report will focus on:
1) The design of the main structural members and fixings to resist all forces to which the building will be subjected.
2) The adequate pre-treatment of timbers against rot and beetle attack.
3) The provision of damp proof courses and membranes.
4) The provision of vapour checks in the wall panels to prevent condensation occurring within the enclosed structure.
5) The provision of vapour barriers against weather penetration.
6) The provision of adequate external claddings.
7) The provision of adequate thermal insulation within the panels.
In a recent structural survey in Chesham by Daniel Stephens MRICS, a pebble dash rendered house that looked solid enough to some (see photo), was found to be originally a timber frame imported from Sweden in 1948.
Whilst some reports are not complementary of timber frame, others like the world famouse Building Research Establishment, see modern timber frames as no less reliable than "traditional" build.
If you need to know about a house you are buying, so you know as much as possible about ongoing costs and potential problems, be sure to insist on a survey by an experienced Chartered Surveyor, such as Woodward Chartered Surveyors.