Rising Damp: what are the dangers?

What is rising damp?

Rising damp occurs as a result of ground moisture being soaked upwards into the walls of a building through the porous materials such as stone, brick and mortar.  It develops if the “damp proof course” in the wall is ineffective or if ventilation is inadequate. By the way, a damp proof course is an impenetrable membrane that is standard nowadays in building practice.

Contributing factors to rising damp may be stormwater or roof water run-off creating too much wetness near the home. Or, it could be that raised ground levels have accelerated the deterioration of the damp course.

Rising damp will often show up as a high tide-like stain on the interior surface of the house walls and can cause blistering of paint, wallpaper and plaster.

Rising Damp_Peeling paint_The Happy Habitat

In its report on rising damp, the ISS Institute notes that water penetration and dampness is the number one problem faced by the construction industry.  While modern buildings keep water out by a system of barriers, old buildings relied on the principle that any moisture entering the building should be able to evaporate.

There is nothing new about rising damp.  It’s been documented for centuries by scholars in Ancient Rome and the UK.  And whether you live in a new or old building, you’d better hope that the correct building procedures were adhered to and have stood the test of time.  You want any moisture on the outside, not the inside.

How common is rising damp?

Unfortunately this building issue is all too common.  While you may think rising damp is purely the scourge of heritage houses (and that is true to some extent), rising damp is not selective.  Many modern homes are afflicted by this insidious problem, as a result of flaws in the damp proof coursing or other poor construction techniques.

In the Australian Bureau of Statistics Housing Survey of 1994 (no more recent data has been released), rising damp was attributed to 4% of all dwellings. So that's 288,000 homes across the country.  Other sources have estimated as many as 45% of solid brick homes over 70 years old are affected and 25% of homes aged 50-70 years.

4 reasons you should be worried if your home has rising damp

Costly to fix - Dampness in the walls of your home will, over time, undermine the very structure itself.  If left untreated, rising damp can carry soluble salts into your masonry which can result in erosion and crumbling from the foundations up.  And, if your home has timber floors then you may additionally encounter wood rot, adding to your woes.  Remediation work can be costly, to say the least!

Damaging to health - Another, less obvious cost of damp is to your health.  Damp walls encourage the growth of mould which can have devastating effects on humans if left unchecked.

Toxic Mould Support Australia raises awareness of mould illness in Australia.  Their list of common symptoms is long and frightening!  It includes upper respiratory complaints, cognitive issues, flu-like symptoms, frequent colds/flus, muscle pain, joint pain, ice pick pain, neurological pain, frequent urination and thirst, headaches, vision problems, insomnia, “tired but wired” feeling, and psychological issues (depression, anxiety, OCD, ADD and emotional dysregulation).

Furthermore, diseases associated with mould illness are usually autoimmune and neuroimmune in nature. For example, myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS), fibromyalgia, multiple chemical sensitivity, atypical multiple sclerosis, Lyme disease, irritable bowel syndrome, POTS, rheumatoid arthritis and more.

Rising Damp Mould Illness www.thehappyhabitat.com.au

Encourages pests - If that’s not enough to have you running in fear of rising damp, how about we talk pests?  Yup, unfortunately moist conditions provide the perfect breeding ground for termites that feed off damp timber (potentially causing even more damage to your home).  Cockroaches too will be coming from miles away to set up camp at your place.

Creates bad odours - And did I mention the musty smells created by rising damp?  Ok ok, you get the picture.  Now what can you do about it?

A stitch in time… How to prevent rising damp

To combat damp, check around your home regularly. Look for blocked vents, leaking pipes and roofing, and mortar crumbling from joints.  According to Australian Handyman magazine, the six signs of dangerous moisture in and around your home are:

  1. Leaking gutters (external)

  2. Mouldy brickwork (external)

  3. Discoloured grout (external)

  4. Peeling paint and plasterwork (internal)

  5. Mildew on walls (internal)

  6. Water stains or tide marks (internal)

Steps you should take to prevent rising damp may include:

  • Improving site drainage and landscaping to deflect rainwater and underground water away from your building.
  • Eliminating design or construction flaws to stop water pooling near the walls.
  • Improving under-floor ventilation, to encourage evaporation and reduce the amount of moisture reaching the walls.
  • Establishing good maintenance - fix your roof, leaking pipes and drains.
  • Remove coatings and membranes that prevent evaporation from the walls. Let nature reduce the moisture load in the walls.

Domain, the real estate experts say “When it comes to rising damp, the key is to act fast. Rising damp can affect the health of you and your loved ones, as well as the value of your property. So don’t let it get any worse – nip it in the bud today.”

Treatment options for rising damp

If you suspect rising damp in your home, then definitely speak to the experts about what sort of remediation work you may require.  The Happy Habitat conducts on site assessments with testing apparatus and can help you determine not only the cause of the problem but help you find a solution.

Typically homeowners have been offered one of three traditional solutions but these all have their drawbacks.  Luckily there’s a fourth option now available.

  1. Underfloor ventilation (if the house structure allows for it).  This could mean installing new vents at regular intervals that allow for natural air flow. It could also involve using a pump to mechanically circulate air below the home to flush out the humid air and replace it with fresh dry air.  The downside of this option is that it’s really only a band-aid solution. The damp remains but the air flow prevents it getting out of hand. Another major problem can occur if you already have mould growing under your house. In these situations, the ventilation can spread the mould spores both under and through the floorboards to the inside of your house!
  2. Installing a new damp proof course. This impenetrable membrane (such as thick black plastic) physically prevents moisture rising from the ground up the walls.  Using this method can be effective but requires extensive building and structural work so tends be costly and time consuming.
  3. Installing a chemical damp proof course. Here, water-repellent chemicals would be injected into the wall.  Unfortunately this approach is not environmentally or people friendly. Volatile gasses (VOC’s) are released into the air and guess who may be breathing them in?

A better solution for you and your family

Fortunately there is a non-invasive and non-toxic solution that offers a 20 year guarantee.  It's our job to help families optimise the environment they live in. That means finding solutions to problems like rising damp that restore the home to one that supports the health of the inhabitants.  To find out more contact us at info@thehappyhabitat.com.au or fill out the form below.

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