Rising Damp FAQs

The Garratt’s Damp & Timber team are experts in damp proofing, with extensive experience in identifying and successfully treating rising damp. We regularly treat rising damp in houses and commercial properties alike across much of London area.

Rising damp is one of the most common types of damp property owners may face in the UK, especially those who live in older homes. Although it’s a relatively prevalent issue, many homeowners aren’t too familiar with the signs of it, why it happens, how to treat it, or how to prevent it.

With this in mind, we’ve compiled a handy guide answering the most common FAQs about rising damp so you can learn more about this problem and what to do if you spot it in your property.

What is rising damp?

Rising damp refers specifically to damp that is caused by groundwater seeping into walls and other ground structures. The process is a capillary action and occurs when electrical charges pull water vertically up a wall, allowing it the seep into porous materials such as bricks and mortar as it does so.

Like all forms of damp, if left untreated, the excess moisture from rising damp can wear away at the structural integrity of the affected area, resulting in potentially extensive and dangerous issues with your property’s overall construction.

What does rising damp look like?

How can you tell if you have rising damp? There are a number of recognisable rising damp signs that differentiate it from other common forms of damp, with the first sign being that any damp patches or wet areas are isolated to below 1.5m from ground level. As rising damp is caused by groundwater moving up the wall, gravity doesn’t allow it to move further than 1m or 1.5m in most cases.

In terms of how the dampness looks, it is not always visible, however, it can take the form of broad damp patches (sometimes called tide marks) across the lower half of your walls. Due to the increased wetness, there may be mould on your walls too, where the wall has cooled and thus suffers condensation.

Externally, you may notice stains and white salting on the brickwork on the exterior of your property, and you may see salt bands on the internal side too.

Rusting of metal angle beads around doors and windows is another tell tale sign.

The excess moisture may cause paint and wallpaper to come loose and not adhere, and in extreme cases, you may also notice the plaster flaking. Your brickwork might also begin to crumble and break down as it becomes saturated, and any metal near the area may also become rusty.

In addition to the appearance of damp, you may notice a musty smell in your home.

What causes rising damp?

There are a few things that may cause rising damp, with the most common being a damaged DPC (damp proof course). A DPC is a protective barrier that is installed a few bricks high during the construction process. There are different types of DPC, with the most common being a membrane DPC or a DPC cream injection. Another common cause is bridging of the damp proof course where external ground levels have risen.

Every home in the UK has been required to have a DPC installed since the Victorian era, but DPCs may need to be replaced because the materials may break down over time. If you live in an older property (built before the 1940s) and there’s no record of your DPC being changed, your property may be vulnerable to rising damp. In a similar manner, it’s possible that if your house was built before 1875, it may not have a DPC at all, and this will also make your home vulnerable to rising damp.

Some homeowners mistakenly bridge their DPC by storing items such as bags of compost against their exterior walls at a height that exceeds the DPC, therefore allowing water to surpass the barrier through a direct route onto the brickwork.

Because rising damp is caused by groundwater, if you live in an area with a particularly wet climate or high levels of sitting groundwater, your property may be more susceptible to rising damp, making it all the more important to replace your DPC every 30 years and get your basement tanked (if you have one).

Where can rising damp occur?

Rising damp can happen in any property with a broken or bridged DPC. Due to gravity, you will only ever see this type of damp in underground or ground-floor rooms. If you have damp upstairs or above 1.5m off the ground, you may be suffering from penetrating damp rather than rising damp.

Can rising damp cause health issues?

Damp can cause mould spores to appear due to accompanying condensation this can aggravate sufferers of eczema and asthma.

How is rising damp treated?

How to treat rising damp depends on the cause, but generally speaking, the most obvious course of action would be to replace the DPC by chemical injection. Our preferred method is to use a damp injection cream, although some homeowners opt for a new damp proof membrane to be installed; however, this involves removing bricks bit by bit & can be a costly exercise.

Another way rising damp may be remedied is to ensure your basement is tanked so that groundwater surrounding the structure is directed away from the walls.

In addition to structural work, you may also have to replace skirting boards, plaster, wallpaper, and/or paint.

What is the rising damp treatment cost?

The cost for rising damp treatment depends on the size of your property and the scale of the problem. For a more accurate price, please contact us to arrange a site survey where we will be able to provide you with a no-obligation quote after diagnosing the problem and understanding its severity.

Can rising damp be prevented? 

Rising damp can be prevented by replacing your DPC every 30 years, tanking your basement, and avoiding butting objects against your home’s exterior walls.

Learn more about rising damp

If you still have questions about rising damp or suspect your property may have it, please contact us to discuss your next steps.