вторник, 31 января 2017 г.

Tips for dealing with damp

Rising damp can present homeowners with a multitude of problems, from salty tidemarks to peeling wallpaper, wet plaster and heat loss. There’s also the health problems brought on by mould, a particular issue if you suffer from a bad chest.


Ensure your damp course provider is approved by the Property Care Association (PWA)
Choose a supplier that offers a 25 or 30 year guarantee for the work
Make sure your home is adequately ventilated before calling in a damp proof specialist

Of late there has been some debate around whether rising damp actually exists. This is largely because of the activities of unscrupulous ‘specialists’ offering a quick fix DPC (damp proof course) when the real problem lies with condensation or inadequate ventilation.

This article examines symptoms, treatments and prevention of rising damp.

What is rising damp?

Rising damp comes about where a DPC is faulty or damaged (or in certain instances missing) or where the ground level around the house has been elevated, perhaps by a new path, flowerbed, patio or driveway.

Water from the ground spreads throughout brick, stone and mortar - all naturally porous materials - and travels up the walls, rather like oil travelling up the wick of a lamp. The ground water consists of soluble salts which can be deposited on the surfaces of the wall as they dry out, bringing in more moisture making the walls feel permanently damp. Rising damp typically affects the lower one metre of the wall but left unchecked it can seep as high as five metres.

In addition to looking unsightly, leading to heat loss and timber decay, it’s also potentially unhealthy as it encourages mould and mites to grow.

How do I tell if I have rising damp?

Rising damp can happen in modern houses but it’s more widespread in older houses. Since 1875 all new properties have been built with a DPC, however the English House Condition Survey conducted in 1996 shows that 13% of pre-1850 and 11% of properties built between 1900-1918 are afflicted by rising damp. 1% of homes built after 1956 are affected but if the damp protection is “bridged”, ie the exterior ground level raises above the interior level, troubles are more likely.

Fortunately it’s easier than you think to spot signs of rising damp:

 Curling or discoloured wallpaper
 Wet or rotting skirting board or timber
 Damp stained walls
 Wet plasterwork or brickwork
 Discolouration or staining of exterior brick or stonework

Beware of incorrect diagnosis

Rising damp is generally misdiagnosed or sold in as an essential by unscrupulous damp proofing companies. The real problem could be:

 Condensation, the most prevalent kind of dampness.
 Malfunctioning plumbing
 Dripping guttering
 Blocked air bricks
 Defective ground and surface drainage

Before you decide to commence any remedial work check all of the above extensively or if in doubt call in several experts for their advice.
How is rising damp treated?

The initial step is a survey to discover the magnitude of the damage. Treatment usually necessitates the installation of a chemical or osmotic DPC which is injected into holes in the masonry to repel water. Alternatively a new damp membrane can be fitted to work as a physical barrier to moisture. Plaster normally needs to be replaced with new salt-retardant plaster and a new skirting board fitted.

How much time/expense is needed to treat damp?

Clearly this depends on the square meterage of affected wall, but as a general guide expect to pay between Ј70-100 per linear metre for the damp proofing. The cost of plastering and reinstating skirting boards and electricity sockets will be extra. For a typical three bedroom house the standard cost of damp proofing is between Ј3-4,000.

For more information about Damp proofing surveys please visit the website 

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