Surveyors guide to: Water Ingress

house drain blocked with root growth DIY project

The primary reason for building materials to deteriorate faster than they might otherwise is the influence of water. We look at water ingress – the introduction of water from outside the building into the structure and internal environment.

Buildings are constructed to prevent water from entering the building. Deterioration over time can open up access to water, sometimes with extremely damaging results.

Typically, faults which allow water entry are located at the intersections of building elements. Common problem areas include:

  • Faulty chimney flashing;
  • Missing or broken roofing tiles or slates;
  • Broken or overflowing guttering;
  • Flat roofs installed at the wrong angle or with a deteriorated surface;
  • Cracked mortar joints;
  • Bridged damp-proof course (e.g. soil build up above the level of the damp proof course);
  • Faulty flashing around windows or doors.

The reasons for water ingress can often be difficult to identify from an external inspection; the problem may be internal, as is the case with defects such as:

  • Plumbing defects;
  • Close-fitting vinyl flooring fitted over un-ventilated timber floors;
  • Solid floors with wooden skirtings or other connected timbers, where no separating damp proof membrane has been installed or where the membrane has been compromised.

Regardless of the cause, water ingress can create damp patches and promote wood rot, discolouration and decay.

The problem is not limited to older, solid-walled properties, as even cavity-walled homes must by necessity compromise the cavity with wall ties, which bridge the gap, allowing water to track across into the inner leaf. Incorrectly injected cavity wall insulation often bridges the outer skin to the inner skin.

Water ingress can be difficult to diagnose and is potentially more damaging than other water problems, such as condensation. It therefore warrants inspection by a property surveying expert, who will identify the root cause and suggest methods for addressing the issue.

Typically, the resolution will be broken down into two parts: closing off the method of entry and drying out affected areas.

Beware of simply drying out the area without addressing the underlying problem, in order to save costs. This may seem financially attractive, but addressing the issue directly will pay dividends over time.

In some scenarios, the cause of water ingress can be located several feet away from the symptoms, such as a damp patch. It takes a trained eye to accurately locate the fault, so speak with your local Chartered Surveyor if you suspect a water ingress issue.