WHAT IS RISING DAMP?
Rising damp is a well-known damp problem 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 for it to occur. It is often misdiagnosed as a result of this, so examination by a qualified surveyor is recommended before proceeding with any treatment.
This page will offer professional guidance on the causes of rising damp, the tell-tale signs of a problem and the treatments and solutions available.
WHAT CAUSES RISING DAMP?
Rising damp is caused by water from the ground travelling 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 (DPC). 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 it is a modern chemical DPC, 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 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 walls, often driven there by the use of non-breathing plasters, renders, paints or vinyl wallpaper.
WHAT DOES RISING DAMP LOOK LIKE?
If you suspect there is dampness in your property but are unsure if it is rising damp, there are common signs that can give you a better idea.
Running your hands around the interior walls where you suspect a rising damp problem will often cause a ‘crunching’ sound of the hygroscopic salts that have been drawn from the ground.
You may also notice other damp signs such as a damp smell or musty smell, damp stains, mould, rotting skirting board and damp patches. Although these can all be caused by other forms of dampness such as rain penetration from damaged external walls, damp cavity wall insulation, broken downpipes or other faults in the building fabric that require structural repairs.
The most important thing to note though is that rising damp only occurs on the ground level as it is moisture from the soil that is being drawn up the walls that causes the 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 instead.
Typical signs that can specifically identify rising damp include:
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. Tide marks will often appear on the exterior wall too.
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.
DECAYED SKIRTING BOARDS
Rising damp can cause rot in timbers it comes into contact with. Look out for skirtings that are cracked and easily crumble. You may also see localised fungus growth on the boards or creeping out of the side. Also, look out for damaged or flaky paint.
SALTS WITHIN THE PLASTER
Salts within the plaster are another clear tell tale sign. These salts are absorbed from the bricks and into the plaster leaving blister-like patches on your walls.
If you see black mould localised above your skirting board it is a sign that there is some form of dampness affecting the area, especially if you have no other evidence of black mould within the property.
IS RISING DAMP A SERIOUS PROBLEM?
Any damp is unsightly, potentially unhealthy and can lead to timber decay. It can also 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 resolve the issue, the less likely it is that damage will occur. This, in turn, should lower the potential costs of treatment.
Rising damp can also be a common cause of more serious property problems if it results in long term damp conditions in the structural timber of your property. Damp timber can attract wood-boring pests like woodworm or damaging fungal infestations like wet rot or dry rot.
The easiest and most reliable first step to avoid these problems is to contact an experienced and qualified specialist such as Wise Property Care.
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, are 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 see rising damp being misdiagnosed. Anyone inexperienced at identifying damp issues may assume that any damp patches on the wall means you have rising damp. Before you instruct any form of treatment in your property, 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 or leaking plumbing?
- Have you had a damp course installed within the property over the last 20 years?
- Is it a possible condensation problem?
- 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
There are four Property Care Association (PCA) approved methods for the treatment of rising damp – chemical damp proof treatment, injection mortar/creams, electro-osmotic treatment or the installation of a membrane.
However, the first thing to our surveyors must consider is if the damp proof course (DPC) is really to blame. Sometimes new external features such as a raised flowerbed or patio installed above an exisiting DPC can be to blame.
However, if the DPC has failed, the PCA approved treatments employed by our specialists are very successful for both modern and old buildings. A rising damp survey will reveal the extent of any problem and allow our surveyor to recommended the most appropriate treatment. This can often be the introduction of a chemical DPC (sometimes referred to as a damp proof injection) into the brickwork followed by the removal and replacement of any salt contaminated plaster and damaged timber.
Once Wise Property Care have applied our treatment programme your walls will be safe, dry and ready for re-plastering. Best of all our work will be covered by a 20-Year Guarantee.
SPEAK TO A RISING DAMP SPECIALIST
At Wise Property Care, we are experts at identifying and treating rising damp. If you suspect a rising damp problem within your property, call us today today speak to a our team or fill out the form below. With our 20 year property repair guarantee, you will have the peace of mind that your property problems will soon be over.