Notice some peeling paint, or marks on the ceiling? Your home could probably do with some damp proofing, and the sooner you take care of it, the less damage you risk.

Don’t wait for mould to appear, or that “musty old boots” smell. By that stage it’s probably also causing a lot of damage and affecting your health, the warmth of your home, and your monthly bills!

Effective damp proofing is essential for the wellbeing of your home and family, so it’s worth taking the time to get it right. But do you need Damp Proof Course (DPC) or Damp Proof Membrane (DPM) and what else should you be aware of? Here are some expert tips to help you choose and install the best damp proofing for your home.

What Causes Damp?

Almost everyone has heard of rising damp – one of the most serious problems we’re confronted with here in the UK – but surprisingly, it isn’t the most common!

We are often faced with water ingress (also known as ‘penetrating damp’ or ‘lateral damp’), underground water ingress, and the most common culprit of all: condensation.

Older homes didn’t have many of the damp proofing tools and materials that are available today, and often need extra attention. Some reasonably effective measures were taken to prevent damp, such as bitumen and slate DPCs in Edwardian homes, but aspects such as solid (early Victorian) walls can lead to more condensation. Late Victorian builds introduced cavity walls, creating pockets of air to prevent moisture from getting through, but decaying pieces of timber and brick can fall into these spaces over time, giving water and vapour a route to follow.

While rising damp can be an issue with older homes, both old and newer builds can experience condensation and water ingress.

There are many ways to deal with and prevent damp in your home, and we stock a selection of quality products in a range of sizes and specifications that will meet the needs of every home. It’s also essential to check your home’s ventilation, and fix any leaks, loose window frames, and blocked gutters or pipes that could be letting moisture in.

With an issue as important as damp proofing, it’s a good idea to organise a professional survey with a reputable professional, so you can make sure your home gets the treatment it needs.

Signs of Damp

Peeling wallpaper, a faint musty smell, bubbling paint, tide marks on a wall, discoloured patches on walls or ceilings, crumbling plaster or bricks, small spots of mould… these are signs of damp in your home, and they can’t be ignored.

The next stage is larger areas of mould and wood rot, a stronger odour, or in some cases walls that feel colder because they contain more water. Those will also mean your heating has to work harder to keep you warm, so it costs you more money. You shouldn’t wait for these signs, and if they do appear, they need urgent attention.

Unusual allergies can be a sign that something isn’t right, so get those checked out. Not attending to damp can lead to more serious health complications such as asthma and lung infections.

Mould and water marks on your external walls also need attention, as they’re a reliable sign that water is getting into those walls in some way.

In a newer home, changes and discolouration are more likely to get immediate attention because they stand out, but damp can be less obvious in older homes where surfaces have already changed over time. It’s easy to attribute signs of damp to the age of a building, but it’s important to have it professionally checked.

TYPES OF DAMP, AND DAMP TREATMENT

We hear about rising damp all the time, so that’s what most people immediately think is their main concern, but there are a few different types and causes of damp in the home. Each of them requires specialised prevention and treatment.

• Rising damp is defined as water seeping upwards into the walls of a home, through pores in the brickwork. This is the damp that creates tide marks on the lower part of a wall, and makes skirting boards rot or feel damp. You may also notice a residue on plaster, cracked skirting boards, or mould that only grows close to the floor.

• Condensation happens every single day due to changes in temperature. It’s more obvious during the winter when warm air inside the home makes contact with colder walls and windows, but you can’t always see it. Condensation can also happen within the walls when warm air tries to escape (to balance with cooler air outside). Over time, condensation pools and seeps into walls and woodwork, and rot sets in. In addition to standard damp proofing, you can reduce condensation in your home by opening windows, ensuring good ventilation, not overheating the home, and installing an extractor fan in rooms like the kitchen where hot appliances create a lot of condensation.

• Water ingress is another common cause of damp in the home. Also known as ‘penetrating damp’ or ‘lateral damp’, this is when older bricks, mortar or plaster allow more water to seep through. It can be caused when blocked gutters and pipes, faulty window frames, or missing roof tiles let water in. Regular maintenance and using good quality materials in construction and repairs are an important back-up for damp proofing to prevent water ingress.

• If your home has an underground cellar or basement, you will need to protect against underground water ingress, which requires special waterproofing.

Damp Proof Courses (DPC) are used to prevent and treat rising damp. These include DPC sheeting, placed between brickwork and blocks during construction, and injectable/chemical DPC, which can be injected into a wall long after construction is complete. Please remember that this protects walls against rising damp, but doesn’t help much with floors or other (more common) causes of damp.

Damp Proof Membrane (DPM) is available in various sizes and has been used in UK construction since the 1970s. It is designed to keep moisture from moving between different areas or rooms. We stock high quality DPM and DPC products – including eco-friendly DPM that’s made from 100% recycled polyethylene.

Damp Treatment Process

If you have damp in your home, look for a professional contractor or damp surveyor who will take you through a thorough assessment and treatment process. They should also provide a guarantee, and a full quote including details of the damp proofing materials/products they will be using.

Our preferred process:

1. Assess the entire home and provide a detailed report.
2. Recommend a tailor-made plan that addresses the causes of damp specific to your home, treats all problem areas, and prevents future damp.
3. Remove and replace any damaged materials, and repair anything not in top condition – if required. (If the damp is not too bad, they may simply recommend steps for you to take.)
4. Provide a maintenance plan to take care of your home well into the future.
5. Complete the project professionally and responsibly.

Costs will depend on the cause of damp in your home, how severe it is, the amount of damage done and repairs needed, and of course, the materials required. As with all aspects of construction and our homes, we believe it is worth spending a little more on quality – and good damp proofing can last 30 years or more.

It’s worth getting a few quotes before you begin, and reading reviews on the surveyors/contractors for similar projects. As always, please feel free to contact the Harlestone Supplies team on 01604 581444 for any advice or queries. We have worked with many damp proofing professionals over the years, and can help you find what you need for your home and peace of mind.

Confused by industry speak... we explain it:

DPM = Damp Proof Membrane

This prevents damp from getting through from one area to another.

DPC = Damp Proof Course

Sheets installed between brickwork to stop damp from rising into a wall.

MVTR = Moisture Vapour Transmission Rate

The speed at which water can get into/through a substance. The lower this rate, the better.