Damp

Penetrating damp image | Rentokil Property Care

Excessive moisture within a building from either internal condensation or intrusion from outside will eventually cause damp problems in a property. The longer dampness is left untreated the greater the chance of other problems such as wet or dry rot occurring. Rentokil offer effective, convenient treatments for damage caused by damp:

  • Professional damp investigation and survey with tailored treatment recommendations
  • Convenient appointment times (Mon - Fri) for a thorough assessment of the extent of any damp damage
  • Friendly and knowledgeable, local technicians will ensure the highest level of safety for family and pets
  • Call us on 0800 0121 437 to arrange for Rentokil Property Care to deal with your damp problems

For more information on different types of damp problems and what may cause them, please see below:

Damp problems 

Problems with damp in a building may be related to a variety of reasons:

  • Lack of building maintenance
  • Poor build quality
  • Design defects
  • Deterioration of building fabric

Dampness in buildings is most often related to one of three main issues:

  • Rising damp - when ground water travels upwards through mortar, sandstone, brick and other porous building materials. This movement of water generates a characteristic "tide mark". This is caused by the salts in the groundwater as they accumulate at the peak of the rising damp due to the effects of evaporation.
  • Penetrating damp - also known as "rain penetration" can occur through walls, roofs, window or door surrounds. Water penetrates the outer skin of a property due to building defects such as damaged roof tiles, cracked pointing, blocked weep holes or defective seals.
  • Condensation - comes from high levels of humid air trapped within a building, where poor ventilation does not allow it to escape. This moisture then condenses when it touches cold surfaces such as windows, walls and ceilings - eventually leading to black mould growth.

There are sometimes other causes of dampness in properties such as leaking pipes or damaged drainage that should not be overlooked.

 

Damp Walls and other symptoms

Damaged walls caused by damp image | Rentokil Property Care

Worried about damp walls? Damp may not be very obvious to spot at first, in many cases it can take several years slow development before the problem is visible. There are a number of signs to look for, which may indicate a problem within a property:

  • Damp, musty smell
  • Mould or mildew – starting to form on walls
  • Staining of wall coverings - peeling wallpaper, blistered paint
  • Appearance on walls of damp patches or fragmenting plaster (spalling)
  • Rust marks – on skirting boards, where nails or screws may be present
  • Rusting on angle beads – on corners of plasterwork

Damp may also be visible externally. Mortar can crumble and salt stains appear on external walls, in severe cases chunks of mortar may fall away from the affected wall.

Preventing Damp Problems

Many types of problems with damp can be prevented through careful building design and construction. Modern buildings in the UK include a damp-proof course that acts as a barrier to water penetration. If however, some damage (however small) has occurred to the fabric of the building - broken slates, blocked air vents, leaking pipes, blocked drains etc... damp may then become a problem. Vigilance and regular maintenance can help prevent such issues.

  • Ensure external roofs, gutters, down pipes and drains are clear from debris
  • Repair broken or cracked slates and tiles, leaking pipes, defective mastic around door and window frames
  • Maintain external ground levels at least 150mm below the damp proof course
  • Keep all air vents free from obstruction to allow ventilation under timber floors
  • Repair any external render and cracked or damaged pointing

In addition, you should regularly check for signs of damp:

  • Check for sings of dampness on internal surfaces of ground floor walls, skirtings etc...
  • Check walls behind furniture, curtains or sofas for any stains on wall coverings
  • Look out for the appearance of mould or mildew on walls

Damp Survey and Treatment

Damp damaged wall and plaster image | Rentokil Property Care

Every damp problem is different. The most effective way to treat damp is to first discover the original source of the dampness and where possible eliminate it - repair roofs, guttering, drains, air vents, maintain ventilation etc... 

A thorough inspection by a qualified surveyor will be necessary to correctly diagnose the types of dampness affecting the property and then survey recommendations can be made for the most effective way to treat the damp problem.

The Property Care Association (PCA) is an industry body that governs the quality of member companies to ensure high standards are maintained. Rentokil Property Care is a member of the PCA.

Surveyors should be qualified to CSRT standard for dampness & timber surveys and to CSSW standard for structural waterproofing.

For further advice on damp problems or to arrange a visit by a surveyor call Rentokil Property Care on 0800 0121 437.