How to deal with damp or mould
Damp can affect any home and, with the obvious health and comfort issues, it is always wise to spot any problems early and remedy them quickly. Here's what to look for.
What are the Causes of Damp?
One of the most frequent problems encountered in the home is damp. Each year, the average home handles continuous downpours of rain water, so it is no surprise that damp can become a big problem for many. Although most damp problems are much less serious than they actually look, whatever the cause, damp can be very bad for our health. From aggravating respiratory problems to encouraging the emergence of mites and mould, the effects of damp can be serious, not to mention making the whole property cold and unappealing.
In many cases, damp can be unwittingly encouraged due to poor maintenance. 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. 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. So let's look at the main damp causes:
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 course has failed to work properly. It can be spotted in a number of ways - namely, if the walls feel damp and cold to the touch, or if there is distinguishing mark on the inside walls. Internal decorations can become stained and damaged, and plaster can become loose.
Any wall in contact with the ground can suffer from rising damp, thus 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. 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. 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 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. 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, Monitor & Treat Damp
There are several simple measures that will remedy damp, so it is worth looking over your property thoroughly before instructing an outside firm to carry out expensive work. The problem may be something you can fix quickly with an anti-damp product or a spot of DIY repair. And preventative measures, or spotting early symptoms of damp, will also prove extremely beneficial in keeping your property warm and dry.
Classic rising damp is usually worse at the bottom of a wall than at the top. The most common cause is 'bridging' - 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. 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. In old properties, it may prove difficult to install a DPC, so chemical methods - injected into the problem areas - may be the only solution.
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. 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. 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. If this is blocked with moss, dirt or cement, clear it thoroughly.
Condensation forms when warm air trapped inside the house meets cold walls, and mould quickly spreads. A portable humidifier, which will suck up moisture in the air, can help, as will maintaining regular heating, and adequate insulation. 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.