WHAT IS RISING DAMP?
Rising damp is a well-known form of damp that affects the ground floor of buildings. Despite the notoriety of rising damp it is not all that common and requires a very specific set of circumstances to cause it. It is often misdiagnosed as a result of this, so examination by a qualified surveyor is recommended before proceeding with any rising damp treatment.
This page will offer professional guidance on the causes of rising damp, the tell-tale signs of a rising damp problem and the treatments and solutions available.
causes Of rising damp
Rising damp is caused by water from the ground traveling upwards through brickwork by capillary action. The water will contain a number of contaminants found in the ground, such as salts, that also travel up the bricks causing further damage to the wall.
The water and salts from rising damp can cause damage to plaster, timber and any absorbent decorative features such as skirting boards and wallpaper. This causes unsightly staining and can lead to rot in structural timbers.
The vast majority of properties in the UK should already be protected by a damp proof course. A damp-proof course is a layer of waterproof material in the ground floor wall that prevents the capillary action previously discussed. A damp proof course can take many forms, but whether it is made of slate or chemicals it can break down over time and this is usually when rising damp occurs.
Damage to a wall can disrupt a damp proof course but they can also be bridged by external factors such as raised flower beds, patios and other cosmetic additions to the outside of a home that can provide ground water with a way around an existing damp proof course
Damp proof courses can also be bridged internally by absorbent materials being added to the inside wall that stretch beyond the damp proof course and meet the bottom of your internal wall. A build-up of absorbent material inside a cavity wall can also bridge a damp proof course.
Any masonry structure unprotected by a properly installed and functioning damp proof course is susceptible to natural rising damp. Damp will rise by capillary action through the pores of the masonry seeking a means of evaporation.
The moisture will continue to rise until it reaches a height where, unless no evaporation is possible, gravity takes over and pulls it down again. This height is seldom more than 1.20m, although deposits of ‘salts’ may be found higher in the internal or external wall, often driven there by the use of non-breathing plasters, renders, ‘tanking’, paints or vinyl wallpaper.
SIGNS OF RISING DAMP
If you suspect there is rising damp in your property, the following signs can give you a better idea:
- Run your hands around the suspected rising damp area. If you have wallpaper on your walls, you may hear a ‘crunching’ sound of the salts that have been drawn from the ground
- If possible, look at the exposed surface of the brick or stone work. Check to see if there are salts forming, that the brick is actually wet (not just the wallpaper or paint)
It is also important to note that rising damp only occurs on ground floor levels as it is moisture from the soil that is being drawn up the walls and thus causing the rising damp problem.
If it is the case that your damp problem is on the first floor or above, it may be that you have a condensation problem or a penetrating damp issue. View our damp proofing web page to help you identify and solve your damp problem or contact your local Wise Property Care branch for help in identifying your property problem.
What Does Rising Damp Look Like?
You can often identify rising damp without using any professional equipment, just looking at and touching your walls can often be enough. Typical signs that can identify rising damp include:
Tell tale sign 1 - Tide marks and damp staining
One of the most common tell tale signs are tide marks left on walls. Tide marks are caused by evaporation and salts from the ground. You will normally notice them anywhere up to a 1 metre above the skirting board.
If you do not notice tide marks, another very common tell tale sign is damp patches or staining. Typically, these damp patches are yellowish or brownish in colour and similar to tide marks, you will notice them up to 1 metre above the skirting board.
Tell tale sign 2 - Peeling wallpaper
Look out for wallpaper coming off or peeling from the wall. You will most likely notice it coming loose from the skirting board first with the corner of the wallpaper turned or curved up
Tell tale sign 3 - decayed skirting boards
As with many forms of dampness, rising damp has the potential to cause rot within timbers it comes into contact with. Look out for skirtings that are cracked, easily crumble or localised fungus growing on or creeping out of the side. Also, look out for damaged or flaky paint.
Tell tale sign 4 - Salts within the plaster
Salts in the form of white fluffy desposits in the plaster similar to the images below are another clear tell tale sign. These salts are washed out of your bricks and into your plaster leaving what can look like blistering patches on your walls.
Tell tale sign 5 - black mould
If you see black mould appearing above your skirting board it is a clear sign that there is some form of dampness affecting the area, especially if you have no other evidence of black mould within the property and the black mould is localised from the skirting board to up to 1 metre above the skirting.
IS RISING DAMP A SERIOUS PROBLEM?
Rising damp is unsightly, potentially unhealthy, often leads to timber decay and can cause heat loss due to the increased conductivity of the walls. If you notice the tell tale signs of rising damp a general rule of thumb is that the sooner you start thinking about resolving the issue, the less likely for more damage to occur and the lower the potential costs to remedy the issue. Often, the easiest and most reliable way to do this is to contact an experienced and qualified rising damp specialist such as ourselves that are familiar with rising damp problems and the variety of rising damp treatments available.
Is Rising Damp a Myth?
There is a long-standing debate around rising damp and whether it exists or not. The cause of this debate is down to unqualified tradespeople misdiagnosing problems such as condensation and penetrating damp as rising damp.
Genuine cases of rising damp, i.e. water rising upwards through brickwork and masonry through capillary action, is a scientifically proven occurrence and absolutely not a myth.
This is why it is important to make sure any damp surveyor hired to assess your property has the qualifications necessary to properly diagnose a damp problem.
rising damp - misdiagnosis
It is not uncommon to hear rising damp being misdiagnosed. Many individuals inexperienced with identifying rising damp issues may just assume that due to the usual tell tale sign of a tide mark on the wall that you have a rising damp issue. Before considering instructing any form of rising damp treatment, consider the following:
- Do you have any faulty or leaking guttering that could lead to your damp issue? Is there vegetation growing out of the gutters?
- Do you have faulty of leaking plumbing?
- Have you had a damp proof course installed within the property over the last 20 years?
- Is it a possible condensation problem? If so check out our condensation web page
- Do you have cracks in the stonework or brick work?
- Do you have damp staining on stonework particularly adjacent to pipes?
- Do you have defecting pointing?
How to Treat rising damp
Firstly, consider if the rising damp (damp proofing) barrier is really to blame. Sometimes new external features such as a flowerbed or patio may have been installed above the rising damp barrier causing rising damp to occur. By lowering these features to below the damp barrier you may cure a rising damp problem by allowing the area to dry out naturally. After that, all you really need to do is to regually open your windows and heat the room.
However, if the rising damp barrier has failed, modern techniques employed by rising damp specialists are very successful and a rising damp survey will reveal the extent of any problem with the recommended and most appropriate rising damp treatment. This could either be the injection of water repellent chemicals into the brick work or the fitting of a new physical damp proof membrane to the area with the removal and replacement of any affected plaster work and damaged timber.
Speak to a rising damp specialist
If you want a visit from from of our expert surveyors then call us today on: 08006522678
Alternatively, you can request a survey online using the form below and out team will get back to you.