Wall showing signs of Rising Damp

Rising damp

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Rising damp

Rising damp is a well known, but misunderstood, damp problem that can affect ground floor walls in buildings of any age. If left untreated, rising damp can create a damp and unpleasant environment in the home. In some cases the added moisture can even result in wet rot or dry rot. Thankfully there are a number of ways to treat rising damp and return your home or business to its natural dry and habitable condition.

There is some controversy surrounding Rising Damp but this is largely down to misdiagnosis by unqualified tradespeople. This guide from the rising damp specialists at Peter Cox will let you spot signs such as damp patches spreading upwards from the base of the walls and the kind of damage rising damp can cause to skirting boards, paint, wallpaper and masonry.

Following current Government guidance Peter Cox can still perform rising damp treatment services in homes and commercial premises while taking all necessary precautions with regards to social distancing and use of protective equipment. To find out how we can help you today while remaining safe, please get by filling in the online enquiry form below. Alternatively, continue reading this page for help and advice on spotting the signs of rising damp and how to stop it.

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What is rising damp?

Rising damp is the name given to the process of water in the ground entering a property by travelling up through the pores in brickwork. This phenomena has been documented as far back as Roman times and is known as ‘capillary action’. Rising damp will stop when gravity and evaporation impede the pull of the capillary action, and this usually results in a visable "tide-mark" around 1m high. That said, other signs of rising damp may be visible above 1m due to non-porous renders or paint on the wall.

Typicaly walls will be surrounded by porous materials like plaster, timber and wallpaper and this where a lot of the aesthetic damage caused by rising damp will be noticed as these material rot and detiorate. Ground water also contains salts that travel up through the bricks and cause white marks to form on the internal wall - another common sign of rising damp.

This soaking up of ground-water is why you are more likely to notice rising damp problems after a period of prolonged or heavy rainfall as there is far more moisture in the ground to make its way into the property. This is is also why rising damp will only occur on the ground floor.

What causes rising damp?

During construction, a rising damp barrier (or damp proof course) should be installed into a mortar joint of low level brickwork to prevent water travelling through the brickwork to cause rising damp. However, over time these original damp proof courses can begin to breakdown or get damaged. Normally, you will not even be aware the damp proof course has failed until you begin to notice the typical tell tale signs of rising damp.

Another cause of rising damp is a damp-proof course being ‘bridged’. This means that either the external ground level has been raised above the barrier (for example laying a flowerbed or raising the level of the driveway) or new render and plaster work has overlapped the damp proof course.

What does rising damp look like?

Understanding what rising damp looks like, and how it differs from penetrating damp or simple condensation is not always easy if you are not trained in what to look for. To help you recognise the differences you can check out our rising damp images below displaying a typical rising damp 'tide stain', damaged plaster, peeling wallpaper and salt marks.

Signs of rising damp pictures

Signs of rising damp

Being able to identify the signs of rising damp at an early stage will allow you to intervene and avoid the more serious consequences.

Take a look at our tips below on how to identify rising damp, and if you are worried your property may be displaying some of these symptoms you can give our specialist team a call to find out the best course of action to remedy the issue.

Tide-mark damp stains on internal walls

The most common sign of rising damp is a “tide-mark” or damp staining along the bottom of the wall sitting approx 1 metre above the skirting boards. As the water evaporates from the brickwork, a tide-mark appears that typically feels damp to touch. The tide mark is often in association with ground salts that have been absorbed into the plaster (see the next tell tale sign).

If a tide mark isn’t visible, yellowish-brown damp stains may appear along the skirting board. This is typically another sign of the moisture within the walls evaporating.

Salts visible in the plaster of internal walls

As the moisture rises from the ground by capillary action, the water contains salt washed out from the brick onto the plaster often leaving walls damp to touch. As the water evaporates, the salt fragments are left leaving a residue and creating fluffy white deposits. The salt draws moisture from the air leaving a permanent damp smell within the walls. Salt in the plaster is almost uniquely an indicator to rising damp and is a very common sign.

Damp and decaying skirting boards

Dependant on how long you have had the rising damp issue, It is possible for skirting boards to begin to rot from the overexposure to water. Things to look out for include:

  • skirting board crumbling
  • visible cracks in the skirting boards?
  • paintwork peeling or flaking

Also be aware of any exposed timbers around the area as this could potentially lead to further problems with wet rot or dry rot if left untreated.

Damp wallpaper

The increase of moisture within the wall(s) can cause damp patches on walls and wallpaper to start peeling away from the wall, particularly around the skirting board or up to 1 metre from the skirting board.

Damp stains and peeling wallpaper can be an indication of condensation issues but by feeling the wall with your hand you may be able to hear the paper crack and crumble due to the salts behind the wall paper drying.

Black mould on walls

Dependent on the amount of moisture there is within the wall and the humidity of the property, black mould can be an indication that there is a form of dampness in your property. If the black mould is located along the skirting board and does not affect other areas of the property, it could be a sign of rising damp.

Rising damp on external walls

Rising damp also shows on the external walls of a property. The most common signs of rising damp on external walls are pretty similar to inside, with metre high “tide marks” and salt deposits being visible.

You may also notice green and brown staining from external debri and vegetation, similar to the kind of stains that occur around broken downpipes.

Rising damp treatment

The most popular method to treat rising damp is installing a remedial damp proof course (DPC) via the damp proof injection method. Remedial damp-proof courses are injected into specifically drilled holes in the affected wall. Once injected the DPC is absorbed by the bricks and creates a water-repellent barrier as it dries.

A damp proof course is a popular way to treat rising damp for a few simple reasons - it has proven to be highly effective, economical and is accredited by all leading trade bodies in the industry. That said, there are other treatment methods available and you can find out more about these on our rising damp treatment page.

Before any remedial damp-proof course is installed, the most important part of the rising damp treatment process must take place - diagnosis. Before assuming there has been a failure with the original DPC, the experts at Peter Cox will carry out a full rising damp survey. Our specialist surveyors will be able to identify rising damp or any other conditions that may be causing a problem such as penetrating damp or condensation where a new DPC would be ineffectual and unnecessary.

How much does it cost to treat rising damp?

The price of any rising damp treatment is dependent on the severity of the problem. Naturally, if the rising damp problem is localised to one small area on a particular wall, the cost would be less than if all ground floor walls were affected and had led to a deep laying dry rot issues.

No reputable firm would be able to provide an estimate of price without first sending a qualified surveyor to attend the property to identify if rising damp is in fact the culprit. If you think you may have identified rising damp then you can discuss it with our contact team by giving your local branch a call, or sending us an online enquiry.

Buying or selling a house with rising damp

Any evidence of rising damp either in the home report or on a viewing is a clear red flag to buyers. Most are aware that rising damp will not resolve itself and some form of remedial treatment will inevitably be required.

In order to negotiate a fair value for the property it is advised that you act to treat rising damp before the property goes on the market. Meanwhile, if you are considering putting an offer in for a house with rising damp, it is in your interests to contact one of our qualified surveyors to visit the property and provide a full damp report along with an itemised pricing guide for any rising damp treatment necessary.

Our rising damp treatment reviews

We are very proud of our reputation as the UK market leaders in rising damp treatment. To demonstrate the high regard that our clients hold us in take a look at some of their comments on our rising damp services from the respected review platform Trustpilot.

Contact a rising damp specialist near you

If you suspect that you may have a rising damp issue, then we are here to help. Our fully qualified specialist surveyors will be able to determine the cause of the problem and recommend the most appropriate course of action. If necessary we have a team of experienced technicains ready to get started resolving the issue for you. 

Get in touch with your local Peter Cox branch or give us a call on 0800 633 5712 for some help and advice. Alternatively, book a no obligation survey online using the button below.

Author: Richard Walker AIWSc CSRT CSSW

Richard has worked for Peter Cox for the last 23 years and is currently our National Technical and Development Manager. With his wealth of experience in the diagnosis of damp and decay within properties, Richard has travelled the country providing rising damp CPD sessions for property professionals.

For more on Richard's qualifications in the damp industry you can view his profile page or connect with him on LinkedIn.

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