Cracks in walls and what they mean21/12/20
Whatever the age of a property, visible cracks are never a good sign. But there are many different reasons why they may be appearing. The most common reason for cracking is due to a shift in the structure of the property. This can be caused by a number of factors, from weather impacts to deterioration or subsidence. Cracking is not always of major concern, as a little settlement, in all property, is not unusual. Very old properties, such as timber-framed buildings, are actually designed to move slightly, to accommodate temperature changes and material age occasionally. If an upper floor is overloaded, due to rooms being used for storage, for example, this can also cause cracks to appear where the ceiling and walls meet.
Subsidence can be a cause for wall cracks, with telltale jagged fissures in gables and around windows often an indicator of movement. This can be caused by loads being exceeded in the structure of a building, or it may be a problem with foundations or ground strength. Something as simple as a leaking gutter can cause water to wash away earth and expose or undermine foundations. Underpinning existing foundations will help to strengthen them, if excessive loads are causing them to fail. Using the wrong lintels in window replacements can also make walls fail, as they are now supporting a load they weren’t designed for. The same can be true of floor joists and beams, which can buckle under increased loads.
An expanding problem
Frost is another cause of external damage to properties. Cracks that may already exist in the mortar or other crevices can be enlarged by water gathering in them in the damp winter months. The cracks can then be exacerbated by the trapped water freezing in sub-zero temperatures, which will then expand. This will widen the crack and the process will continue as long as the crack is left exposed to the elements – re-pointing to the brickwork or filling the crack will normally remedy the problem. The same can be true of thermal expansion and contraction, causing cracks to brickwork. This leads to cracks appearing in brickwork, which can lead to the general deterioration and weathering of the construction materials, which will eventually cause visible damage.
The elements can also cause havoc with external rendering. This is the mortar covering often used as an external finish, over brick or blockwork. It can become cracked and deteriorate over time and allow water ingress into gaps, between the brick or blockwork and the external render. Weak, or poorly mixed or applied, render may not be properly adhered to the wall to begin with and will fail considerably sooner than a well-applied render. Waterproof paint can protect render and a seal coating of this can help to allow the building to be protected from inclement weather.
Up on the roof
Settlement on old roofs can be a sign that joists have become rotten and sagged. This will require the timbers to be replaced and the root cause of the problem to be found. A leak, for example, could be causing water to rot the support timbers. This is a prevalent problem around chimneys, where lead flashings connect the brickwork to the roof covering. Nail sickness and the deterioration of old slates can also cause roof problems, with rotten nail heads allowing slates or tiles to slide out of place and allow water to get in.
The earlier you tackle the issue of cracks and begin to remedy it, the less damage will occur. If you need to talk to an expert and think you may issues with your property, or a property you wish to buy, contact our expert surveying team today. Qualified surveyors from our Staffordshire and Shropshire offices carry out RICS Home Buyer surveys every day.