What’s Rising Damp?
Rising damp is a rare form of moisture that affects building walls. Groundwater is pulled up through the walls due to capillary action. This occurs when water is sucked up through small channels in the bricks, comparable to a series of straws. This water contains salts, which also travel up the wall.
Porous construction materials such as plaster and timber in floorboards, joists and skirtings are located around the affected wall. These can easily absorb water, and you may spot signs of damp rot in the wood. For assistance in identifying and treating damp rot, refer to our dedicated pages.
Rising damp often reveals itself through the damage it can cause to a building’s internal walls. Plaster and paint deteriorate, wallpaper slackens, and a visible stain appears on the wall in the form of a tide mark. Additionally, salt blooms may be seen on the inside surface. This is a clear indication of rising damp and can lead to paint and plasterwork detaching. Mortar may also dissipate on the walls, leaving white salt stains.
What Causes Rising Damp?
To prevent water from rising, most structures have a barrier known as a damp proof course (DPC) built at their lower wall level. These can be made from non-absorbent, water-resistant materials like slate, bitumen or plastic, depending on when the property was constructed. In older homes, these physical DPCs may have failed or not existed at all, leaving no barrier to stop water from travelling up the wall. Sometimes the DPC might not require any intervention, but it may need to be bridged. A design flaw can cause ground moisture to ascend past the DPC.
- Instead of: “We have received a total of two hundred and fifteen orders thus far”
- Paraphrase: We’ve had 215 orders to date.
- Instead of: “We have had a total of one hundred and fifty-five customers in the past year”
- Paraphrase: We’ve serviced 155 customers in the past 12 months.
- Debris in the wall or under the flooring can be found.
Plastering that overlaps the damp proof course (DPC) on the interior or exterior of a structure should be avoided. Raised areas of land outside the damp-proof membrane need to be taken into consideration. The cavity lacks adequate insulation material.
Solid flooring is an ideal choice for those seeking a durable, long-lasting solution for their flooring. It is a reliable option that provides a sturdy surface and is easy to maintain. Moreover, it is available in a variety of styles, colors, and textures, making it an aesthetically pleasing option. Adjoining garden walls and intersecting masonry structures.
Signs Of Rising Damp
Property owners should be aware of the tell-tale signs of rising damp. Identifying the problem quickly can help resolve it swiftly. If you are unsure, seek the advice of London Damp Treatments experts.
Walls With Damp Stains And Tidemarks
Tidemarks on walls are a frequent indicator of increasing dampness. They are caused by wetness evaporating and salt from the ground travelling up the wall. Visible from the base to roughly one metre above the ground, tidemarks can be easily identified. Alternatively, look for patches of brown or dark yellow on the wall, which are also likely to be present between the bottom of the wall and one metre up.
If the damp is visible more than one metre up the wall, this could be due to rising damp, though it is more likely a penetrating damp problem. It is important to be careful in making the correct diagnosis, as both rising and penetrating damp may be present.
The Appearance Of Damp Or Wet Patches On Walls
If there are damp patches on your walls, rising damp is likely to be the culprit. These patches are typically found on the lower wall section of ground floor homes, caused by capillary action, whereby moisture from the ground rises up through the brick or stonework. If the property lacks an effective Damp Proof Course at the base of the wall, it will be vulnerable to rising damp. The ground floor alone is vulnerable to this issue.
If you have a damp issue on a floor higher than the ground level, it is likely to be of a dissimilar kind (likely penetrating damp or exorbitant condensation).
Salts Within The Plaster
Rising damp is often signalled by one of the most familiar indications: the appearance of a tide mark on walls, usually between one and two metres high.
Moisture is drawn upwards through the stonework via capillary action. As humidity rises, the wall absorbs salts from the soil, which travel into the property and damage the plaster and decoration. These hygroscopic salts attract moisture from the air and cause the wall to become damp. If you touch the wall, it may feel moist. As the moisture in the wall evaporates, the salts are brought to the surface, occasionally leaving a white coating.
If your wall is affected by rising damp, it must be addressed with the addition of hygroscopic salt to resolve the issue.
Wallpaper Or Paint Peeling
Rising humidity often leads to wallpaper and paint peeling. An increase in moisture within walls is the cause of this, which is particularly noticeable near the skirting board. In such cases, the wallpaper will usually start to peel away from the wall above the skirting board, with its edges curling.
Wallpaper or paint that is peeling could suggest a condensation or penetrating damp issue in the house, requiring an exact diagnosis to ensure the right repair plan is put into action to resolve it.
Plaster That Is Flaky Or Bubbling
If you observe flaking, bubbling, crumbling or powdery plaster on the walls and ground floor of your house, this may be a sign of a damp issue, likely caused by rising dampness. Rising moisture can cause plaster to deteriorate and crumble, leading to visible damage to decorated and plastered walls. This can prove costly for property owners, so it is best to address the issue as soon as possible.
Skirting Boards And Flooring Rotting
Skirting boards and floors can deteriorate if the damp problem in your home is neglected for a long period. This is because excessive moisture can weaken the timbers, allowing a fungal attack to take hold. Much like other types of damp, rising damp can cause wood rot where it comes into contact. Property owners should avoid any skirtings or other timbers that show signs of cracking or crumbling when touched. If the home has been affected by long-term dampness, visible fungal growth on the skirting boards or flooring timbers may be present.
Damp And Musty Smell
The unmistakable aroma of rising damp in a property is a sure sign of the presence of damp. Even when there are no visible signs of wetness, the particular scent of damp – which is often described as unpleasant, musky and moist – can be detected. Identifying the type of damp causing damage to the property can be difficult if there are no visible signs, in which case a specialist damp surveyor may be required. Different treatments are needed for different types of damp, so it is important to get a correct diagnosis in order to get the problem sorted out quickly.
Black Mould
The presence of black mould in the base of your walls is indicative of moisture. If present, it suggests you have a condensation issue. On the flip side, if it is only on the lower half of the walls in the ground floor, then it could be rising or penetrating damp, which must be dealt with.
Fasteners Made Of Iron And Steel That Have Rusted
Unprotected iron and steel are prone to rusting if exposed to high levels of moisture over a prolonged period. This can compromise the security of the property as rust causes iron and steel fasteners to weaken, leading to potential structural issues. Cavity wall ties, in particular, can fail when rusted, jeopardizing the structural integrity of the property.
Bricks And Mortar Crumbling Between Bricks
Ground-floor walls can be severely affected by rising damp. Repairing crumbling bricks and mortar can be costly. Rising damp can cause bricks or mortar to become loose or crumble, becoming very porous and allowing penetrating damp to seep into the masonry, which in turn can cause further damage to internal walls. Luckily, fretting is a condition that can be easily spotted and the decaying bricks or mortar addressed. When checking your external brickwork or stonework, take a look at the cement joints.
Finding Help To Tackle Damp Problems
Our extensive experience with London Damp Treatments allows us to assess your property’s issue and recommend the most effective remedy for rising damp. We’re here to lend a hand. So, if you have any queries concerning damp, don’t hesitate to contact us on 0208 0162508. Our technical team are on hand to assist and ensure you get the right solution for your property’s issue.