How To Spot Damp And Deal With It...

To solve a problem you should know the cause of the problem, so we start by asking...

What are the Causes of Damp?

One of the most frequent problems encountered in the home is damp. Each year, the average home in the UK copes with around 25,000 gallons of rain water, so it is no surprise that damp can become a big problem for many homes. Although most damp problems are much less serious than they actually look but damp can be very bad for our health and property.
Damp can aggravate the respiratory system and encouraging the emergence of mites and mould and this will make the effects of damp become serious, not to mention making the whole property cold and unappealing.

In many cases, damp can be unwittingly encouraged due to poor maintenance, although there are several causes of damp in the home but all can be remedied.
Damp can be in or around the roof, walls, floors, windows, doors or pipe-work on any property and often if there is a damp patch visible inside the home the cause can be identified from an issue on the exterior, for instance a wet patch at the top of a wall might be due to a leaking gutter outside.

Types of Damp

Rising damp - is caused by water soaking up through porous materials into the floors and walls of the property and usually occurs in houses which haven't got a damp proof course or the damp course has failed to work properly.
It can be spotted in a number of ways such as if the walls feel damp and cold to the touch or if there is distinguishing marks on the inside walls, also internal decorations can become stained, damaged and plaster can become loose plus any wall in contact with the ground can suffer from rising damp, affecting walls both inside and out, however it rarely comes up further than one metre in height.


Penetrating damp - is caused by issues with the building or plumbing where a problem has allowed water to enter the property.
Symptoms will usually only occur during wet weather but it can affect roofs and ceilings along with walls. A watermark might appear and grow if the water continues to enter and if not fixed plaster may start to perish.
Penetrating damp can sometimes be caused by gutter or roof problems which have allowed rainwater to spill onto and saturate areas of wall.
Penetrating damp is most frequent in older homes which have solid walls as a new build property with cavity walls offers more protection and is unlikely to suffer from this type of defect. Penetrating damp can be tricky to pin-point and often may require expert help.


Condensation - differs from rising damp and penetrating damp in that it's caused by excessive moisture that cannot escape from the property (as opposed to water coming in) if there isn't sufficient ventilation, condensation will arise and moisture will be in the air even if you cannot see it.
Using radiators to constantly dry clothes, not opening windows, poor heating and even portable gas heaters can all contribute, mould may appear on walls, ceilings, furniture and even curtains, there is usually a strong musty smell present and unlike the other types of damp, condensation is largely caused by the inhabitants of the property rather than problems with the actual building.


How to Prevent & Treat Damp

Rising damp - is usually worse at the bottom of a wall than at the top apart from blocked airbricks, the most common cause is 'bridging' and that is when when earth from the garden butts up directly on to the house wall trapping moisture.
This is a common problem but can be remedied by simply digging away all the soil to see if it makes a difference but if not, you may need to look into installing a damp proof course (DPC) or if you have one it is probably failing to do its job.
As in old properties it may prove difficult to install a DPC (damp proof course) so chemical methods are used by injection into the damp problem areas and this may be the only solution but if the damp is rising through floorboards, a damp-proof membrane may have torn so it would be best to look into re-fitting the damp proof membrane.


Penetrating damp - forms when water gets in from the outside so the first step is to check everything in and around the property.
Examine gutters, downpipes, flashing, rendering and window frames in detail for any damp or signs of damp and always make sure that downpipes are unobstructed and if the guttering has seen better days think about replacing it with new easy to fit plastic guttering also check the rendering to see if it's cracked plus look at re-sealing any gaps around window frames, be sure to check underneath window sills as there should be a drip groove to shed rainwater before it gets to the house wall and remember if this is blocked with moss, dirt or cement, clear it thoroughly.

An ill fitted roofing felt on a flat roof will also cause damp and cracked wall can let in water, so repair with suitable filler and fit insulation rubber or weather bars to all door frames.
An exterior waterproofing fluid is useful if your exterior brickwork has become porous, this will give it a new water resistant skin and it only needs to be painted on when the brickwork is completely dry and should also reduce heat loss inside the house.


Condensation - forms when warm air trapped inside the house meets cold walls and mould quickly spreads.
Test the area by placing condensation test strips on the coldest walls these will change colour if condensation is occurring and get a portable humidifier which will suck up moisture in the air as well maintaining regular heating and adequate insulation also think about installing film glazing which can help if windows are the cause, humidity controlled extractor fans can be a great help too.
To remove mildew caused by condensation, scrub well with a mix of hot water and bleach, leave it to work for several minutes and then clean off thoroughly.

Remember always to seek advice from a qualified and reputable surveyor, who will give a truthful evaluation of the problem.