How To Check For Damp In A House

old homes can suffer from dampness issues leading to mold
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Damp is a common problem in North American as well as UK homes, with approximately 1 in 5 houses being affected. However, it is much more common in areas with older housing stock and sometimes it can be hard to know whether a house really does have damp problems or if it is something else. There are some surefire signs of damp that you can check for and there are steps that you can take to damp proof your home to prevent it from getting damaged. Let's take a look.

What Are The Tell Tale Signs Of Damp?

If you suspect you may have damp problems in your home or you want to check if there are potential damp issues in a home you are looking to purchase, it can be worth getting a full damp survey conducted. But before you do so, there are some signs of damp that you can check for off your own back.

  • A musty smell that permeates the house
  • Excessive condensation on the windows
  • Damp patch or dark patch on the walls
  • Mildew or mould growth on the walls, ceilings, or floors
  • Cold surfaces on the walls, ceilings, or floors
  • Wallpaper peeling or peeling paint
  • Rotting skirting boards
  • Increased humidity throughout the house
  • White residue on walls, ceilings, or floors (which is salt left behind after the water evaporates)
  • Excess moisture and visible water droplets on the walls, ceilings, or floors
  • Wet clothes in your wardrobe

If you notice any of these issues, there is a chance that your house could have a damp problem. If this is the case, there are steps that you can take to damp proof and deal with the issue, depending on what type of damp you are dealing with.

What Are The Different Kinds Of Damp Problems?

There are broadly three different types of damp: condensation, rising damp, and penetrating damp. These all have different causes and will take different methods to deal with them.

Condensation

Condensation is the most common type of damp problem and is particularly seen in older properties. It is caused by a combination of excess moisture in the air and insufficient ventilation.

A lot of the activities that we take part in at home can give off water vapor. This can include cooking, showering, drying clothes, and more. But many houses don't have enough ventilation to properly move this moisture outside, so it collects in the air inside the home.

Over time, this moisture will start to cling to the internal walls, windows, window frames, and other surfaces in the home. And if it is left, it can start to cause damp issues.

The classic signs of condensation include water droplets on the windows, walls, or mirrors and are caused by the warm water vapor interacting with the cold surface. If left untreated, this can develop black mold on the walls throughout the home (not just on the ground floor) and the classic moldy smell of damp.

How to cure damp caused by condensation

To get rid of the mold associated with condensation damp, you can use a damp cloth and soapy water, as well as an anti-fungal treatment for the mold itself. But this won't fix damp caused by condensation in the long term. For that, you will need to take steps to prevent it from coming back.

These include:

  • Adding extra ventilation systems such as extractor fans to rooms like the kitchen and bathroom
  • Investing in some dehumidifiers
  • Make sure the door is closed when you are cooking or showering and that the windows are open
  • Don't dry clothes inside the house on radiators or clothes horses, drying them outside if possible
  • If using a condenser dryer, ensure that it is in a well-ventilated area
  • If using a tumble dryer with a vent, make sure that it leads to the outside
  • Leave windows open whenever possible
  • Try to keep clutter against walls to a minimum

Penetrating damp

Penetrating damp is caused by water ingress through the external walls. This might be due to a defect or damage or because of bricks that have become degraded enough to be porous.

Penetrating damp will typically leave you with damp patches on your internal walls as well as damp staining on your exterior walls. You might also notice drips and puddles as well as black mold that is isolated to specific areas.

This is not an issue that should be left for long. Penetrating damp can cause serious problems if it is left untreated. These can include:

  • wet and dry rot
  • crumbling and wet plaster
  • water damage to the outside walls
  • damaged masonry

How to cure penetrating damp

Dealing with penetrating damp will usually require the help of a professional to conduct damp proofing. They will be able to create a damp proof membrane that should stop the moisture ingress and prevent water damage to your walls.

Rising Damp

Rising damp is one of the most serious types of damp problems. It is caused by water moving up from ground level through the walls through capillary action.

Signs of rising damp will include a tide mark at around one meter high, damaged timber, peeling wallpaper, and white marks left from the soluble salts in the groundwater.

If left untreated, rising damp can cause structural problems with the walls, timber, and masonry of your home, and it can also cause damage to the aesthetics of your property.

How to treat rising damp

This is another damp issue where you will likely need to call in a professional. They will often place a damp proof course, which is a physical barrier that prevents water from moving up the wall. They may also suggest more intensive methods if the risk of damage is high.

The Bottom Line

Living in a damp home can be very unpleasant, and diagnosing damp can be tricky especially if you are trying to specify the kind of damp. There are some telltale warning signs, however, that can help you to spot dampness and decide on the best course of action.

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