Dry Home

Different Types Of Damp

What kind of damp is affecting my home?

The three most common kinds of damp are rising damp, penetrating damp and condensation. To work out the best way to treat the damp in your home, you'll need to work out which of these you have.

We have added some information below to help you try and discover the type of damp you may have. However we are here to help so give us a call and we will be happy to come to your home and diagnose the problem and suggest solutions.

Rising damp

rising dampTypical early stages of rising damp

Rising damp is caused by ground water moving up through a wall. Stone and brick are porous and can act like a sponge drawing water up from any wet soil or surface the stone or brick is in contact with. Most walls allow some water in, but it’s usually stopped from causing damage by a barrier called a damp-proof course. This is usually a horizontal plastic or slate strip in the wall.

If this is missing or ineffectual, your wall may suffer from rising damp. This type of damp can also happen when the level of the ground outside your home is higher than your damp-proof course, allowing water to get above it.

Symptoms of rising damp

If you have rising damp you may notice damaged skirting boards and floorboards, crumbling or salt stained plaster and peeling paint and wallpaper. There may also be a tide mark along the wall.

Rising damp is caused by water moving up through walls so will always be at the base of a wall rather than in say a top corner. Damp in a top corner is probably caused by penetrating damp or condensation.

How to deal with rising damp

To deal with rising damp you have to make sure that your damp-proof coursing is working. If your damp-proof course isn't working effectively you may need a new one. The best why to determine this is to call in an expert to carryout a detailed assessment and we can help here. If it is determined that a new damp course is required the most common remedy is for a damp specialist to drill holes in your wall and inject damp-proof liquid or cream.

Penetrating damp

Typical early stages of penetrating damp

Penetrating damp is caused by water leaking through walls. This type of damp may move around within a building, but this is through horizontal movement rather than by travelling up walls (as is the case with rising damp). Penetrating damp is usually caused by structural problems in a building, such as faulty guttering or roofing.

Symptoms of penetrating damp

Penetrating damp often shows up through damp patches on walls, ceilings or floors, which may darken when it rains. You’re more likely to get penetrating damp if you live in an older building with solid walls, as cavity walls provide some protection.

This form of damp is typically caused by faulty guttering, faulty roofs, or faulty alterations that cause water to find it’s way into the building.

How to deal with penetrating damp

You'll need to work out the cause of penetrating damp before you can treat it. Start by examining your gutters and downpipes for leaks or cracks. Check the roof – including the pointing, gaps between tiles and flashing (where a roof meets the wall). Check window frames and doors to see if there are any gaps.

Once you've found where water may be leaking through to your walls, you'll probably need to ask a builder to repair the fault. We are damp specialist not builders but can definitely help so feel free to give us a call.


condensation mouldTypical early stages of condensation damp

Condensation is the most common kind of damp and is caused by moist air condensing on cool surfaces such as walls and windows. In Australia this can happen all year round due to our humid client however it will mostly occur when there is a temperature difference between air inside of your home and the air outside your home, say over night or during winter. This is because the cool air outside is what causes the walls and windows to be cooler than the room temperature. Any moist air that comes in contact with these cool surfaces will in turn cool meaning it can carry less moisture and so condensation forms.

Condensation can be exacerbated by poor ventilation, and heating that comes on and off, as this allows warm, damp air to condense. Of course during the night and during winter we close up our houses to keep the warm air in and the cold air out and this traps the moisture inside.

Symptoms of condensation

You may notice water droplets on windows or walls, see dark mould appearing and/or notice an unpleasant smell. If left untreated, condensation can damage paint and plaster but more importantly damage your health as it promotes mould growth. Please see our Health Page for more details.

How to deal with condensation

The easiest and cheapest way to stop condensation is to equalize the temperature between the inside of your home and the outside of your home. Of course in most parts of Australia this is impossible as it’s simply too cold outside for half of the year. Therefore we have to remove the moisture from the air before it has a chance to condense on the walls and windows. This is where a dehumidifier comes in. Dehumidifiers are specifically designed to do one job efficiently, remove water from the air. To see how they do this please check out our What Is A Dehumidifier Page.

Our Dry Home dehumidifiers are also easy to use. Simply plug them in, set the desired humidity with the built in humidistat and that’s it.