There are several different types of damp problems that can affect a property. From condensation damp to penetrating damp to rising damp. There are other specific issues that can occur too. For example, wet rot and dry rot – and sometimes damp affects specific areas of a property in a particular way and requires a particular treatment, such as basement damp. It can get quite confusing because with so many different types of damp problems, many different damp proofing solutions are available too. When choosing a treatment it’s important that it is appropriate to the type of damp problem you have.
So, here is a guide to the best damp proofing solutions for various damp problems.
Condensation Damp Proofing Solutions
We’ll start with perhaps the easiest type of damp problem to resolve – condensation damp.
With condensation, as long as it is identified and dealt with soon enough, the damage to a property is likely to only be superficial and cosmetic, rather than structural. There should be no need for any major work. The problem can usually be rectified both quickly and cheaply – and very often you probably won’t need to call in any professional help.
Condensation is caused by an excess of moisture within a home. Moist air condenses on walls. It’s often, although not exclusively, more of an issue during the winter months as at this time of the year the walls of a property are much colder than the air inside it. It’s also usually more of an issue in rooms that naturally have more moisture in them, such as the kitchen or bathroom.
The most obvious solution for condensation damp is to improve ventilation. This can even be as simple as just opening windows more often and for longer. In fact, anything that reduces the amount of moisture in the home is a good way of reducing condensation problems. A couple of examples of this in practice would be putting lids on pans when cooking and not drying washed clothes on radiators.
Often though, condensation will require a little more than just changing a few habits about the home. Common and effective ways of improving ventilation include installing air bricks to external walls (these are bricks specially designed with small holes in them to allow for ventilation), or window vents that can be added above windows. Any type of vent is a useful solution. These could be air vents on internal walls or for sealed chimneys and also roof ventilation tiles.
The most effective means of improving ventilation is the most important. It’s also most expensive, but should only cost a few hundred pounds. That is a kitchen and bathroom fan. As mentioned earlier, these are the rooms in the home that create the most moisture so it is the kitchen and bathroom that require the most ventilation.
The other main damp proofing solution for condensation damp is internal damp proof paint. The most important thing to remember about damp proof paint is that it is only useful once the actual cause of the damp has been identified and treated. But, as long as you take steps to improve ventilation as well, using a damp proof paint can be a really effective solution for condensation damp. It is cheap, relatively easy to apply, and is particularly suited for use in rooms that are prone to moisture, such as kitchens and bathrooms (which is where condensation damp is most common). Damp proof paint will cover up unsightly mould stains and condensation stains on walls and ceilings and greatly reduce the likelihood of them returning.
Penetrating Damp Proofing Solutions
With condensation damp you basically know what has caused it – a lack of ventilation. In most cases, once you have considered how you might improve ventilation and reduce moisture in the home, you are on a clear road to recovery.
With penetrating damp you also know the cause. But with this type of damp it will be a result of some sort of structural or building defect around the home. Often it’s down to the likes of cracked guttering, broken roof tiles, a leaky pipe or a damaged seal around a window. It might be something that is really simple to fix or it could be fairly major. Whatever the defect is, it will need to be addressed before you can think about a suitable damp proofing solution for the property.
The solution you choose will be determined by the extent of the damage that had been caused, the extent to which water has penetrated into the inner walls.
Cavity wall treatment is a common damp proofing treatment for penetrating damp. Most modern homes and many built since the 1920s feature a cavity between the external and the internal wall. The thinking behind this is sound as it creates a space for the moisture that penetrates through the external wall to evaporate before it reaches the interior wall.
However, where this protection is interrupted, either by a window or some pipework, it can lead to problems. Installing a cavity trayis one way of dealing with this. There are many different versions of cavity trays, but essentially all designs will serve the same purpose – they act as a drainage system. Small holes, known as ‘weep holes’ in the outer wall allow any water to drain away from the interior wall.
Cavity unblockingis also sometimes required. If the cavity has become filled with debris, such as broken bits of brick, this will take in moisture from the external wall and transfer this to the inner wall. Clearing blockages from a cavity is relatively straightforward and inexpensive, however.
If damage to an exterior wall is the cause of penetrating damp, once this had been rectified, exterior damp proof paint is often a suitable solution. This will give the external wall the layer of waterproofing protection it needs for the future.
In more serious cases of penetrating damp, tanking might be the best solution. This involves sealing the walls of a property in a damp proof material, unfortunately, as this requires removing the damaged wall and coverings prior to the tanking (and obviously being put back in place and decorated afterwards), the bill for a tanking treatment could be quite high.
Tanking will only usually be required if a fair bit of damage has been caused to the walls.
Rising Damp Proofing Solutions
Rising damp is usually caused because a damp proof course has failed (or there simply isn’t one in a property). Typically, a plastic strip (or slate in older houses) forms the damp proof barrier known as a damp proof course. Essentially, the damp proof course stops water rising up the walls beyond a certain level (as it will naturally do). If the barrier is broken, the water continues to rise – hence the term rising damp.
So the most obvious damp proofing solution to rising damp problems is to insert a new damp proof course. This is actually more simple than it sounds. These days, an injectable DPCis most commonly used. Here, waterproofing chemicals are injected into holes drilled into the wall in a horizontal line, forming a waterproof barrier. Creams are often used too, and DIY kits are available.
The ground level of a property needs to be at least 15cm below the line of a damp proof course. If this is not the case, soil excavation will be required. This is a relatively simple treatment that usually costs just a few hundred pounds.
In cases where walls are considerably damaged, tanking is, again, a possible remedy. Following the insertion of a new DPC, a damp proof membrane is often installed to the interior wall. This is basically a plastic sheet that forms an additional waterproof barrier for the inner wall.
Wet Rot Damp Proofing Solutions
Wet rot is a serious condition that causes timber in a property to decay due to continued high levels of moisture over time. Often, timber that has become infected with wet rot can bet cut out and replaced with fungicide-treated timber. In the more serious cases, timber in a property might need to be completely removed.
Basement Damp Proofing Solutions
Basement damp is not a specific type of damp, but a basement is an area of any property that is always going to be particularly susceptible to damp problems, as they are usually below ground level. Tanking is often used as a damp proofing solution for basements. Damp proof membranes are a popular treatment too. This can either be in the form of the conventional sheets of membrane, or in liquid membrane form. Both types can be applied to floors and walls.
So, in terms of damp proofing solutions, you have lots of options that we have covered in more detail above:
- Improve ventilation
- Damp proof paint (both internal and external)
- Cavity wall treatments
- DPC (damp proof course)
- DPM (damp proof membrane)
- Soil excavation
- Fungicide-treated timber.
That’s 8 different solutions in all. Bearing in mind the various types of DPC and DPM, and you’ve actually got many more than 8.
The main thing to remember here is damp proof problems should always be treated on a case-by-case basis, but you can rest assured that there will be a damp proofing solution for every damp problem.