Problem Constructions

Problem constructions

There are 3 main types of construction especially prone to structural problems.

Timber Frame

Timber frame buildings are relatively common. Unfortunately so is cement render on timber frame. This traps damp in the frame, and sometimes leads to rot of the frame. Repair can be costly. Prevention consists of using only lime or earth based renders on the building, and only lime or earth based porous paints. Cement renders and modern impermeable paints should be avoided.

Earth Buildings

Known variously as cob, earth, adobe and other names, earth buildings are part of Britains historic housing stock. While these work well enough as designed, common modern alterations can lead to significant structural problems. Cement render tends to cause damp walls, and when the cob reaches a certain level of water content, it loses its strength and can collapse. Although not common, there have been cases where the cement render had become structural due to failure of the cob, caused by the cement render.

Cement rendered earth should generally have its render removed, and be rerendered with lime. Precautions are needed in doing this, as it could rarely cause collapse if done wrongly.

Replacement roofs can sometimes be an issue with earth buildings, as earth buildings require generous roof overhangs, and these are not normally provided on modern roofs.

Reinforced Concrete Buildings

Reinforced concrete buildings suffer from rusting and consequent expansion of the reinforcing steel, which breaks the concrete apart. Most of the compressive strength of the building material is thus lost. These are known as a defective building type, and obtaining mortgages is difficult if not impossible.