Rising Damp?

Rising damp buildings may be defined as the upwards flow of moisture through a permeable wall structure, the moisture being derived from groundwater.  This moisture rises through the pores (capillaries) in the masonry by a process loosely termed as “capillarity” which cause the masonry to act like a wick.

Rising damp varies in severity depending on of several factors including the level of groundwater, the pore structure of the masonry materials (brick, bluestone, sandstone, mortar etc…) and the rate of evaporation away from the wall surface. It requires treatment because it has a number of undesirable effects on the structure of the building. Like cancer in humans the longer it is ignored the more severe the consequence.

Rising Damp or Rising Salt Damp?

These two headings are often the cause of confusion. Rising Damp becomes Rising Salt Damp when salts are present in the soil and are drawn up with the moisture. In Australia Rising Salt Damp is particularly prevalent in South Australia where it is referred to as Salt Damp due to the high salinity in the soil. On the Eastern seaboard and in the West where the soil contains less salt it is more commonly referred to as Rising Damp.

How do you know if you have Rising Damp?

  1. Decorative Spoiling – Rising Damp and the accompanying salts can cause plaster ro deteriorate and paint to blister.

  2. Erosion of the Building Fabric – Ground salts introduced into the wall by rising damp can attack and dissolve the binders in brick, stone, and mortar causing them to lose their strength and structural integrity. Crystalising salts can exert such forces that the mortar, brick, stone microstructure is destroyed.

  3. Increased Heat Loss – Dampness in porous building materials causes a reduction of insulation properties as air in the pores is replaced by more conductive water. The thermal conductivity of a wet brick has been found to be approximately twice that of a dry brick. Not only does this increase the risk of condensation but increases winter heating costs.

  4. Health Effects - It has been widely documented that excessive dampness in buildings can have negative effects on the health of it’s occupants.

rising damp rising damp risiung damp damp window

If any of these symptoms are in evidence then there is the risk of rising damp being present. However a process of elimination is required as other cause of dampness in buildings need to be eliminated as they require other remedial treatments.

1. Lateral Damp. This is where there is soil, dirt, or a garden bed, etc. which is higher than the inside of the wall where dampness is evident and is entering the masonry laterally. A cellar situation or walls built into the side of a hill are obvious cases where lateral damp would be the cause. Read More

2. Condensation.  A common cause of dampness which can be identified even without a moisture meter if it is evident high up the wall especially over a metre high. Rising Damp normally does not rise above a metre in height. Read More

3. Mould. Mould growth is associated with condensation and is grows as a result of long term untreated condensation. Read More

4. Falling Damp. Again, if the dampness is more evident higher up the wall, wait for a rainy day, the heavier the better, go outside and check the gutters and downpipes for evidence of overflow into the top of the wall. Read More

5. Leaking Pipes and Shower units. If the only walls to have evidence of damp are on the perimeter of a “wet” area such as a bathroom, laundry or kitchen then diagnosis by a plumber pressure testing pipes and checking shower units could eliminate the possibility of rising damp. Read More

N.B. Always consider the above as possibilities if the house is less than 40 years old.

Having identified the cause of moisture is rising damp then it needs to be treated by introducing a new damp proof course. Sanding back damaged walls and/or plaster and repainting, covering the wall with plasterboard and any other band aid remedy will prove to be both a waste of time and money as the problem would not have been resolved.  There is some urgency introducing a new damp proof course at this stage as rising damp in masonry is like cancer  in humans, the longer you leave it untreated the more serious the condition especially if salts are present as evidenced by white powder on the surface. The reason the salts cause so much damage is that they are continually moving. On dry days with low moisture in the air they contract then on wet days or days of high humidity they expand so they are continually expanding, contracting, expanding, contracting until the masonry starts to crumble and mortar turns to dust.

How long does this take? Who knows as there are many variables, it could be years or tens of years but it will happen unless treated.

Rising Damp Treatments

In the big picture there are two ways to introduce a new damp proof course, mechanical and chemical injection.


Mechanical is where the operator removes 2/3 bricks at a time, introduces new plastic sheeting, replaces the bricks and repeats the process along the length of the wall.

Very efficient
Could affect the structural integrity of the wall
Labour intensive and expensive
Chemical Injection
Paraffin Based Solvents

Chemical injection is where damp proofing ingredients are introduced into the wall via a “carrier” by injecting into predrilled holes. Traditionally the carrier for many years has been a paraffin based solvent which is injected under pressure or by gravity feed.

Pressure Injection

Pressure injection, as the name implies, is where the solvent is pumped into the wall via rods inserted into the predrilled hole by using a motor driven pump.

Messy, smelly and can have an adverse affect on asthma sufferers
The solvent injected under pressure will take the course of least resistance where there are fissures in the masonry resulting in uneven distribution.
Sometimes bursts through into adjoining rooms damaging unprotected floor covering
Sometimes blows back through adjacent predrilled holes with similar disastrous results
Efficient application is dependent on the expertise of the operator
Labour intensive and expensive
Gravity Feed

Gravity feed is where the holes are predrilled at a 45% angle into the wall and open ended bottles with nozzles are introduced one to each hole along the wall and the solvent then poured into the open end of the bottle which then gravity feeds into the wall.

More efficient as even distribution of the solvent is guaranteed
Less risk of damage
Messy, smelly and can have an adverse affect on asthma sufferers
Time consuming as it can take over 24 hours to gravity feed depending on the porosity of the masonry
Unsightly, making rooms inhabitable during the time of the process with inconvenience to the householder especially where bedrooms are involved
Labour intensive and expensive

More recently cream carriers have superseded paraffin based carriers.

Cream Carriers

Safeguard Chemicals in England developed the first water based cream carrier “Dryzone” in 2000. Damp Busters (Australia) Pty Ltd introduced it into the Australian market place in 2003.


Australian History: Dryzone was originally offered to our major competitor in Australia and for whatever was rejected by them. We were, at the time, the new kids on the block, being incorporated in 2001, and contacted Safeguard, as they had not approached us, with a view to securing the Dryzone agency. Safeguard agreed to send us samples for testing and to say we were more than impressed with the results would be an understatement.

Previously to 2003 we had been using paraffin based solvents as were all other operators offering chemical injection. Within six months of introducing Dryzone into our range we gave away paraffin based solvent injecting and went solely with Dryzone.

Our major competitors denounced the cream technology claiming that it was not effective especially for Australian conditions. An interesting claim as rising (salt) damp is rising (salt) damp wherever it is found in the World and no more virulent than in English conditions. Now some years later the majority of those same detractors have now introduced creams into their own range none of which have tested to be as efficient as Dryzone which is now being sold in 12 countries around the World and has proven to be the World leading product for eradicating rising (salt) damp by chemical injection.

For us this has proven to be a “Pretty Woman” experience as we have the Australian agency for this premier product with hundreds of successful applications including heritage buildings with not one failure.

So how does it work?

Dryzone is injected with a caulking gun by inserting the metal nozzle into pre-drilled 12mm horizontal holes drilled at 110mm centres along the lowest mortar course above ground. Using the same capillary action that the moisture in the ground used to invade the wall in the first place Dryzone slowly and evenly disperses to a 70mm radius around each hole along the mortar course and into the masonry over a 7 day period.

Proven most efficient chemical injection system.
Water based, no mess and no smell.
Injected by hand pressure thereby minimizing any spillage.
No bottles sticking out of wall.
Fast. Will treat a whole house in 1/3 of the time taken with solvent method therefore saving $$$$$$ on labour.
All rooms including bedrooms can be used the same day as the treatment with no disruption to lifestyle.
No adverse effect to asthma sufferers
Pet friendly
BBA approved.
Some risk of wastage by over filling holes
Rod Carriers

Safeguard have done it again and have now developed over the past 4 years the Dryrod system which supersedes Dryzone.

What are Dryrod Damp-Proofing Rods?

Dryrod Damp-Proofing Rods are the next generation treatment for rising damp. They provide a higher level of performance and quicker installation speed than any other rising damp treatment currently available.
Dryrods are 12mm diameter, 180mm length, fibre rods that contain a powerful water repellent. The patented, and BBA Approved, Dryrod delivery system ensures the correct dose of active ingredient is delivered to the wall every time, permanently eradicating rising damp.
No fuss, no mess, no stress.

How to Install Dryrod Damp-Proofing Rods

The Dryrod Damp-Proofing Rods are simply introduced into a series of 12mm holes drilled into the lowest available continuous mortar course. No special equipment is required.
Once the damp-proofing rods are installed, they diffuse the active ingredient deep into the wall before it cures to form a water-repellent barrier. This prevents the damp from rising up the wall.


Number of packs required per 5m stretch of wall:

Wall depth

4½″ (110 mm)

9″ (220 mm)

13½″ (330 mm)

Number of packs per 5m




Full installation instructions can be found on our DIY page.

Why use Dryrod?

As the latest development in the treatment of rising damp, there are numerous advantages to using Dryrod Damp-Proofing Rods:

  • The most effective form of rising damp treatment available — Dryrod outperforms all tested competitor products.
  • Extremely quick and simple to install — Simply drill holes in a continuous mortar course and insert the required number of damp-proofing rods.
  • Permanent eradication of rising damp — The active ingredient contained within the rods spreads through, and bonds with, the mortar in a wall, providing a permanent solution to rising damp.
  • No specialist equipment required — No costly pumps or lances are needed and only a standard hammer drill and 12 mm drill bit are required plus a sharp cutting tool such as garden secateurs.
  • No chemical mess to clean up — Conveniently foil-wrapped packaging and a simple installation procedure means no spillages.
  • Delivers the correct dose every time — Each rod is accurately dosed with exactly the correct amount of water-repellent.
  • Proven to work on highly-saturated walls (even up to 95% saturation) — Tests show that Dryrod Damp-Proofing Rods outperform even premium damp-proofing creams at high saturation levels.
  • Low-hazard — Dryrod Damp-Proofing Rods are solvent free, odour free and non-caustic.

The Importance of Effective Damp-Proofing

Naturally, homeowners want the most effective products available to be used to treat rising damp in their properties. Creating the best possible barrier to rising damp minimises moisture in the wall and blocks the build-up of ground salts.
For this reason, Dryrod Damp-Proofing Rods have been designed to form an effective damp-proof course in walls of all types and have been tested under conditions of up to 95% saturation, where it has been shown to outperform all tested competitor products.
This is important because no two walls suffering from rising damp are the same. In particular the physical properties of the mortar used to construct walls can vary considerably and this can have a significant influence on the effectiveness of any rising damp treatment.
Dryrod Damp-Proofing Rods are effective in a wide range of conditions, including:

  • Saturated walls (up to 95% saturation)
  • Low alkalinity mortar
  • High alkalinity mortar
  • Low porosity mortar
  • High porosity mortar
  • Lime-based mortar
  • Cement-based mortar

Low Hazard, Dryrod Damp-Proofing Rods are solvent free, odour free and non-caustic
Proven most efficient system out performing Dryzone
Easiest system to install only requiring a hammer drill, 12mm drill bit
and sharp cutting tool such as garden secateurs
Absolutely no risk of spillage so no mess
Delivers correct dose every time so no risk of applicator error therefore
suitable for DIY
Fast, quicker than Dryzone to install
No smell, rooms treated are habitable the same day
No averse affect on Asthma sufferers or pets
Suitable for all different mortar courses
BBA approved
No apparent