On the ground floor of your home, the render and paint at the base of the walls are flaking and bubbling, with a salt-like substance underneath, possibly a musty smell. You are likely looking at rising damp. Left untreated, it can cause all sorts of problems.
What is rising damp?
Rising damp is groundwater that travels up through brick or stone walls by capillary action. When it reaches the wall surface it dries, leaving the salts dissolved in it. How high the water will go depends on the pore structure of the bricks and mortar, as well as the rate of evaporation. The finer the pores, the higher the water will reach, in some instances even going over 1.5m.
Rising damp is essentially a failure of the damp course, which is the moisture barrier built into the foundations of homes of brick or stone. Older homes have damp courses of slate, which can crack allowing water to rise. Rising damp can also happen in modern homes where the damp coursing has been insufficient or, commonly, where paving against the foundations is up against the damp course, allowing water to bypass it.
Rising damp doesn’t just affect the wall material and surface, flaking paint and peeling and staining wallpaper. The moisture can spread into nearby woodwork, rotting and decaying timber floorboards, floor joists and skirting boards.
Our approach to rising damp treatment
With years of experience in homes of all ages, we are able to diagnose different types of damp and offer the best solutions on the best treatment and prevention.
Treating rising damp is a specialised process. We use a silicone-based chemical injection system which effectively makes a row of bricks in the foundations into a new damp course. A series of regularly-spaced holes are drilled along the bricks and injection lances are placed into them. The holes are sealed with rubber expansion washers which also hold the lances in the brickwork. The silicone-based chemical injection fluid is then pumped through the lances under high pressure, forcing it into the capillaries of the bricks. Even after the bricks are saturated with the fluid, it continues to penetrate through the masonry and mortar joints by capillary action for approximately a day after the injection.
Depending on the construction of your house, severe rising damp may also require replacement of the render or other wall surface up to a height of 1.5 metres to allow the moisture to escape before rerendering, replastering and/or repainting.