Dampness Diagnosis & Treatments
Damp patches on walls after rain – What could it be?
After a day or more of heavy rain, we hear from a great number of homeowners and facility & asset managers that they have noticed damp patches on the walls.
There are many causes of excess moisture in the structure of a building, such as leaking pipes and damage to gutters and roofs. However, a high proportion of damp problems in buildings are caused by rain penetration, condensation or rising damp.
Diagnosing the cause of dampness in a building is vital so that correct treatment and repair can be carried out to address the source of the problem.
When the diagnosis is wrong, the treatment fails and the damp issue remains.
Many of the visual signs of the three main categories of damp in buildings may look quite similar to the untrained eye. This is why penetrating damp and condensation can be mistaken for rising damp or vice versa.
There are 3 main categories of dampness
- Penetrating Damp
- Condensation
- Rising Damp
For each different category of dampness and the cause thereof, a different solution of remedial treatment and repair is required.
1.Treating Penetrating Damp
If the cause of the penetrating damp has been identified as failing guttering, window / door frames or roofing, these need to be repaired as well as replacing damaged plaster and timber work.
If the water is entering through the wall to floor joint, an effective and lasting remediation is to inject the joint with flexible hydrophilic polyurethane along the length of the wall to floor joint.
The hydrophilic polyurethane grouts seek out water in a crack, they absorb into tight cracks and pores bonding to the wet concrete – creating a very effective and long-term solution in stopping leaks via a concrete crack or construction joints.
2.Treating Condensation
If the cause of the damp has been identified as condensation, the cure may be as simple as installing a good quality ventilation system that encourages movement of the air from inside the building to the outside. Damaged plaster and timber work need to be repaired or replaced.
3.Treating Rising damp
This treatment involves injecting a damp-proof course (DPC) into a location where no physical DPC is present.
Holes are drilled at regular intervals. The distance between the holes will vary depending on certain variables such as the type of brick, cavity and how far the product travels when injected. The holes are then filled after the process is completed.
The product works by lining the pores of the substrate to reduce their size so water can no longer pass through, but air still can. The method works on moving cracks, wide gaps or voids.
More about common signs and how to treat damp walls…
This article was contributed by Anne Nilsen of Waterstop Solutions.
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Very informative and well written article, credit to the author. I urge people who are interested in the topic to follow the link. A lot of quality information here, will be passing this onto my builder.
Thank you very much for your positive feed back and for passing this article on to your builder. I hope that they will find the information useful.
Please feel free to contact the Waterstop Soutions team if there is anything we can assist with.
Ph: (07) 3205 1899
Email: admin@wsqld.com.au
Re 1 and 2, assuming the moisture penetration is within the building format plan, is the unit owner responsible for rectification or the Body corporate? The situation may be that water is entering through the wall to floor joint or around or under a door or window adjoining a balcony which is not common property. Condensation will often appear within a bathroom which is clearly not common property. Water penetration causes are often difficult to source due to the water traveling along cracks under doors or tiles in the unit above where the ‘fault’ is within the format plan of that lot. The ‘membrane’ is not installed within the walls and doors of a unit.
I find your post to be very informative and I appreciate you explaining the treatment process that goes on for each different type of damp issues. I think the walls in my basement are experiencing a rising damp problem, so I am grateful that you explained holes are drilled at an even gap to allow the water passes through and once the process is complete, the holes are filled. I feel very much more at ease to call the repairman after knowing this.
Hi Kristofer,
Thank you for your message. I’m glad that you found the information helpful. Regarding treatment of rising damp, if that is indeed what had been diagnosed to be the issue in your basement (it’s very important to correctly diagnose the , I’d like to clarify the process that we use for Injectable Damp-Proof Course (DPC).
First and foremost, the purpose of this system is to, as the name implies, inject into position a damp-proof course (DCP) where none is currently in place or where the existing DPC has failed. Damp proof courses are used to control rising damp and resultant damage.
The process typically involves the following steps:
We drill strategic holes at regular intervals into the middle of the area to be treated. The distance between the holes will vary depending on certain variables such as the type of brick, cavity brick and how far the product travels when injected.
The injectable DPC product is fed into the holes to treat a continuous layer of the wall.
Once the process is complete, the holes are then filled with concrete repair material.
The DPC formulation we use has the added benefit of not repelling itself once set – you can continue to apply further treatments for a deeper seal wherever and whenever required. This is a distinct advantage in using this product over other water-based versions.
The product works by lining the pores of the substrate to reduce their size. Water can no longer pass through the pores, but air still can. The method is not effective on moving cracks, wide gaps or voids and non-porous substrates.
Please feel free to contact our team should you have any queries as we would be happy to help.
Kind regards from Anne,
Waterstop Solutions
(07) 3205 1899
admin@wsqld.com.au
https://waterstopsolutions.com.au/
I appreciated it when you shared that it is important to diagnose the cause of dampness in a building so that correct treatment and repair can be carried out to address the source of the problem. In this way, the issue can be solved as soon as possible. I would like to think if a company is dealing with rising damp, it should consider hiring a reliable service that can provide the necessary treatment.
A few days ago, it started raining around here, and it made us realize how our walls looked damp after last night’s storm. My wife and I are relieved you talked about consulting with an expert before taking any corrective measurement to avoid choosing the wrong repair solution, so we’ll look into it right away. We’re grateful for your tips on damp issues and how to identify them. https://www.precisionbuildingnsw.com.au/retaining-walls