How to check for damp in new home buys

You’ve found what looks like your dream home, you’ve had a viewing, and you’re excited to move in. Check this first!

Fail to do so, and you could be the next story on a DIY horror show. The last people on there were soon forced into spending thousands on a damp proof course in a futile attempt to save their home from penetrating damp and rising damp. What they thought would turn out to be patching up a couple of missing roof tiles soon turned into the nightmare they thought would never end.

Let’s press ‘pause’ there and start putting your mind at ease!

The best approach is always to pay for a damp survey as part of the home-buying process. That way you won’t be caught off guard by issues like persistent damp patches, a musty smell that never leaves, and external walls that just cannot stand up to the elements.

Let’s take a look at everything you need to know.

The different types of damp

Understanding damp and its causes will help you understand what’s really going on when you speak to the expert who conducted your home’s damp survey.

Rising damp is when poorly sealed foundations allow groundwater to be sucked up into your basement floor and internal walls.

Penetrating damp is another common damp problem and is when moisture makes its way through your outside walls resulting in mould growth inside.

You may also find there is excessive condensation inside, both on wall surfaces and around window frames and sills, due to a lack of circulating warm air.

Regardless of which type of damp issues your prospective new home is suffering from, it will soon turn into the perfect breeding ground for black mould growth.

How to spot excess moisture

Excess moisture will result in condensation issues around your windows that cause pooling of water on the sills and around the frames. You may also notice that there are a lot of cold walls in your home that feel slightly damp to the touch — this is when the water has condensed onto the outer surface.

If the room feels humid regardless of the weather outside, this is a sure sign that a damp proof course is needed because the air inside is holding too much water.

Other warning signs of excess moisture are the formation of dark patches on the walls, damp skirting boards, mould growth, and other fungi. Your wall surfaces can also display a tide mark which is one of the telltale signs of rising damp.

How do you start fixing damp?

Damp and mould issues are caused by too much moisture, cold temperatures, and not enough airflow. If black mould growth is allowed to flourish on the damp patches, you will quickly experience health problems in the form of chronic breathing issues.

Hiring a professional to identify damp is the first port of call — or getting them to report damp on their survey if you have yet to exchange contracts.

Penetrating damp problems are typically corrected by a damp proof course that addresses poor ventilation (extractor fans need to be installed), poor cavity insulation (injection treatments are common), and low-grade external walls due to cracked and absent render.

Rising damp is a little more complex, and a damp proof course will involve a damp specialist installing water-resistant materials in the form of a membrane that lines the lower floor of the affected area.

While it may be tempting to go ahead if you spot damp during your visit, further investigation is always advised so that you can:

• Get the correct diagnosis and understand the scope and extent of the problem — particularly for older properties
• Decide whether or not you are prepared to go ahead with the purchase of the property without removing mould — you will have to pay for this yourself
• Ask the seller to pay for a damp proof course to tackle penetrating damp and rising damp before you exchange contracts
• Or ask to go ahead with a reduced selling price, which reflects the cost of you correcting the issues highlighted by your damp specialist during the course of the damp survey

The problem with damp issues is that they look superficial but virtually always have a complex set of overlapping factors. The root cause can be hard to handle as there may not be an obvious cause.

Should you still buy a house with rising damp or penetrating damp?

This is very much a personal decision, but we would strongly advise against going ahead until a professional damp proof course has been completed and the damp has been fully rectified.

Damp problems can require extensive remedial work to external walls, lower levels of the home, and cavities, and all of this should be carried out by a fully trained damp specialist.

While a DIY approach to correcting damp issues may be tempting when all you want to do is continue buying a house you think you will love, you are just saving up problems for the future.

Hiring a damp surveyor who knows how to distinguish between a lack of warm air, complex lateral damp, and damp problems caused by leaking pipes will ensure that damp issues are always solved in the quickest possible time.

Given how quickly visible mould can take hold and stop you from being able to do everyday tasks like drying clothes in your utility room, correcting the affected area is of paramount importance.

Now that you know what The Federation of Damp advises, we’re going to answer the questions you’re bound to have on the tip of your tongue right now.

Does my home insurance cover damp treatment?

The home policies of the individual insurers vary and generally do not include damp treatment.

How Much Does Damp Devalue a House?

Depending on the moisture level, the house can lose up to 10% of its value.