Do you think your home has a problem with rising damp?

Rising damp occurs when retained moisture in the walls evaporates leaving behind soluble salt marks on the plasterwork and walls. If evaporation is not allowed in cases of defective paint finish, then salt concentration increases.
Symptoms of rising damp can be seen and felt. Improper plumbing and drainage, faulty gutter work, floods and condensation of warm air against a cold wall can result in rising damp problems in the home. Also, when structures lack installation of a damp proof course or have an inadequate damp proof course due to age or improper installation, then rising damp can also occur.

Rising damp is often misdiagnosed and unwanted treatments are introduced that eventually cause more symptoms of rising damp. Rising damp can affect your health resulting in respiratory illness, skin and visual issues. Rising damp therefore needs to be attended to as and when it is found in the home.
There are various rising damp treatments available. Trench digging below the damp proof layer, modifying the damp proof course, injecting chemicals into the walls and also to simply remove the affected bricks. Our qualified expert will talk you through the best option for your rising damp problem and quickly get a plan of action together to eradicate it all together and get your home back to a comfortable place to live.
Expert analyzing and accurate treatment prolongs the longevity of the building and promotes a healthy dwelling aswell as saving money on misdiagnosis.

Call the experts at London Damp Specialists Ltd to eradicate the damp immediately by calling us on Outer London 020 8528 3864 or Inner London 020 7458 4864.

Signs of damp
Recognising rising damp and dealing with it is essentially done by using a moisture meter to measure the moisture content in the wall and also by visual signs such as tide line, yellow or brown stained patterns formed on the walls up to 1m from the skirting board and fluffy, elevated, powdery salt deposits washed out from the bricks, block or stone onto the plasterwork. Misdiagnosis leads to waste of money, time and effort for those involved. A Rising damp proof course must be introduced to the property to prevent rising damp in the future.

What causes Rising Damp?

Numerous reasons affect the longevity of buildings and infrastructures, dampness being one of the worst. Rising damp or salt damp occurs when the ground water rises upwards through the pores of the permeable wall by the capillary action. Retained moisture content then evaporates through the permeable surface leaving behind soluble salts taken from the source and from the building materials. The left behind salts are emitted out through the plasterwork and settle as salt deposits on the walls. If evaporation is not allowed in cases of defective impermeable paint finish, then salt concentration increases resulting in thick crystalline deposits in the form of flowers. If evaporation occurs within the building material, salt deposits within the pores of the surface.

The most common factors that influences the movement of moisture upwards is the failure in ground and surface drainage systems and the use of slopes without proper drainage, improper plumbing as well as flood catastrophe. Also condensation of warm moist laden air cooling to dew point against a cold surface influence the rising damp condition. Sometimes, hygroscopic salts present in materials absorb moisture and result in bloom patterns at fluctuating relative humidity levels in unoccupied structures. When structures lack installation of a damp proof course or have a damp proof course that is inadequate due to its age or improper installation, then rising damp occurs.

When this damp proof course is breached by another structure or left over building materials, then rising damp becomes prevalent by the creation of a bridge for moisture to travel from ground over the damp proof course, up the wall. Additionally, when the neighborhood lacks a damp proof course or the damp proof course is higher, moisture can travel around the damp proof course from the neighbour into the resident’s area causing rising damp. Rising damp is often misdiagnosed and unwanted treatments are introduced that can eventually cause more symptoms of rising damp.

Treatment of rising damp

A damp proof course is a water proof layer in the wall or both walls (if cavity wall is seen), about 6 inches from the outside ground on the external wall and under the raised timber floor or near the concrete floor on the internal wall, in which both the courses are on the same level. If the course is breached by debris or building materials, then water travels around the course and up the wall. If the area next to the external wall is higher than the damp proof course installed, then water is allowed to travel up through the area and cross to the wall over the damp proof installed, acting like a bridge. These factors must be considered when dealing with rising damp.

Rising damp treatment can be simplified by unblocking the blocked cavity wall, removing or adjusting the bridge-inducing structure by trench digging below the damp proof layer, removing the breaching object from the damp proof course, and modifying the old into a new damp proof course to extend the lifespan of the wall. The damp proofing involves removing the affected bricks or stone and replacing with new materials. Another method is to pressure inject chemicals into the walls by drilling through the brickwork to create a new damp proof course. Treatment options are:

  • Water repellant chemicals in the form of gels, Creams
  • Pore blocking salt mixture (cement based mortar)
  • Osmotic water repellence through embedded wires

If the plaster is just stained but sound then redecorating without replastering is sufficient. Sometimes replastering the rising damp walls will increase the damp and mould issue. Careful examining of the walls can optimise the best treatment plan saving time and cost.
Prevention of rising damp issues include the construction of proper moisture sinks, isolating vulnerable building materials and maintaining proper ventilation and drainage systems.

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