K Lee and Co – Top 10 Residential Building Defects

Written by: Kevin Lee on January 15, 2014

12-05-14 226

Top 10 Building Defects:-

We have prepared a list of our 10 most common building defects found on residential surveys, should you be purchasing a property it might be worth taking a look through our most common defects found on residential surveys:-

  1.  Damp to External Walls – Often brought about as a result of failure of the Damp Proof Course (DPC) or sometimes the external ground levels have been increased and this bridging the DPC height (usually 150mm above external ground level).
  2. Failed Rainwater Goods – The most common failure points to gutters and down pipes are to corner locations and rainwater outlets. A blocked gutter can cause damp issues / failure of masonry and also in the long term lead to structural issues. Most defects that we witness are blocked rainwater outlets, corroded metal gutters, brittle /cracked rainwater goods and also leaks / failure of rainwater goods below ground.
  3. Failed Roof Coverings - One of the most common failures of slate roof coverings are the nail fixings rusting/corroding and leading to the slates slipping. On both concrete and clay tile roof coverings, common failures are the actual roof covering itself eroding / cracking and bringing about a failure.
  4. Structural Failure of Roof – There are many potential failures of roof structures, some of which are roof spread, failure /sagging of timber purlins, racking of roof trusses, woodworm, wet rot and dry rot to name but a few common causes of the  failures of roof structures.
  5. Structural Alterations - Many building defects are brought about by alterations to the original structure and whereby inadequate specification of materials has been employed or poor design. An example of this might be where load bearing walls have been removed and poor specification / installation of the supporting replacement beam has occurred.
  6.   Eroded Pointing – Pointing is the outer face of the mortar bedding of the brickwork on a external wall. Pointing  to masonry walls has traditionally used a lime based mix on older properties however on newer properties a harder cement based (usually Portland Cement) based mix is used. Generally eroded pointing to the exterior of a building might be due to the elevation being on a exposed location or a failure of the rainwater goods over. Often there is also some erosion to the brickwork also present.
  7. Condensation – Condensation within a property usually occurs when there is a high ‘relative humidity’ level, this is the measure of the moisture content within the air. When the measure of ‘relative humidity’ reaches 100% this is known as the ‘Dew Point’. As the relative humidity increases past 100% moisture droplets form as condensation, usually on cold surfaces. Condensation has been a particularly common problem when windows  historically have been replaced with a UPVc plastic windows. Newer UPVc windows generally have trickle vents which aid ventilation (helping to reduce relative humidity). Relative Humidity levels increase within a property as temperatures drop, the moisture level is also affected by ‘life style’. Life style factors which might affect high relative humidity could include the number of building occupants, drying clothes internally, cooking to name but a few activities.
  8. Leaking Flat Roof – Flat roof’s are generally constructed with a mineral felt covering however asphalt roof’s, glass reinforced plastic roofs are also common place. Mineral felt flat roofs (depending on specification) can have a life expectancy generally between 10-20 years and therefore these are quite commonly found to be defective. Common defects include ponding (roof not draining effectively), crazing / cracking of the felt, defective flashings and also UV ray degradation of the outer surface.
  9. Settlement / Subsidence - When assessing a property an appropriate diagnosis of the causation of a defect is required and any appropriate remedial solutions to be employed. On assessing structural movement within a property it is important to distinguish between settlement of the building and also subsidence. Settlement is different to subsidence in that the cause of the movement is due to the self weight of the building causing compression of the sub-soils below, whereas subsidence is usually caused by a change in the ground conditions.
  10. Windows/Doors – UPVc windows and doors common failures are the failing of the sealed glazed unit and moisture build up is found within the glazed unit itself.








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