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Waterproof Lab

Rising Damp

Rising Damp Problems?

How To Treat Rising Damp?

As experts, one of the things that we hear a lot about from clients is the fear of rising damp and, more importantly, their reservations about, how to deal with it. However, let’s put aside the debate on how to treat it and start with an understanding of if you have the issue; in other words, how do you know that you have the problem in the first place?

In this article, we’ll go over how to correctly identify damp rising in your home or place of business and talk about how it is different from common dampness-related issues. Plus, we’ll bust a few common myths. Finally, we’ll talk about how this issue can be addressed.

What is Rising Damp?

It is a rare form of dampness that affects mainly the walls of buildings like flats and condos. It usually occurs when there is enough moisture to seep through the ground and then travel through the walls using what we refer to in physics as ‘capillary action.’ In most cases, what’s happening is groundwater is being sucked up via small tube-like structures in the bricks; it is like having a series of straws. The water mainly has salts which too travel with the water through the wall. Just about any type of structure can be affected by rising damp.

You will also have porous building material often near the affected wall, like timber and plasterwork. Usually, there are joists, and floorboards, etc., near it. The materials help conduct the rising dampness because they absorb groundwater, and usually, you can identify this by checking for timber rot.

Rising dampness is initially determined by checking out the damage usually starting by inspecting the internal walls of a structure. The first and most common sign is the peeling of paint and plaster. If you have wallpaper, then that too will start peeling off. After a while, a visible stain will appear on the wall that appears to be a tide mark, and that is usually how far the groundwater may have reached. It should be your goal to stop rising damp from proceeding any further.

In some cases, you might also see the salts blooming, which too is associated with rising damp and leads to the debonding of paints and even plaster. Over the course of several years, if not addressed, the mortar will start to crumble and be replaced by white salt stains on the wall.

Yes, rising damp is a problem that can be remedied using a DPC chemical barrier strategically pumped into the affected areas of the inner and outer wall.

The best way to treat instances of rising damp is to use a DPC chemical barrier by a leading brand. Make sure to hire an experienced professional who uses the best quality DPC barrier. That way, you can be assured of years if not decades of not having to deal with rising damp

Depending on the extent of damage, fixing rising damp can be expensive. However, the key is to spot signs of it early on and hire a professional to address the issue using the best materials that money can buy. Limiting the issue early on can save you a great deal of money compared to waiting for later.

The signs of rising damp include:

  • Tide marks left behind by salts.
  • Staining of the walls coverings, blistering paint, and peeling wallpaper.
  • Various types and sizes of dark patches on the walls which feel wet to the touch. However, you will want to determine if the masonry and brickwork are wet and not just wet plaster or damp wallpaper.
  • A musty smell.
  • Fragmented plaster and discoloration.
  • Decaying wood or timber like those used for the floor joists, skirting boards, and floorboards.

What Causes Rising Damp

Many buildings are constructed with a barrier installed on the lower level of the wall, which is meant to prevent rising damp. The barrier is also called DPC or damp proof course. The material is made from water-resistant items like bitumen, slate, plastic and is meant to be non-absorbent. However, it isn’t uncommon for the physical DPCs to fail, especially as the structure ages. Also, if you live in an older house, then it may not even have a DPC. When the DPC fails, nothing stops rising damp except for rising damp treatment.

We’ve also seen instances where the DPC has remained intact, but it was bridged. What that means is despite the DPC barrier, the dampness was able to travel up, and that’s down to a construction failure.

Is this Damp problem more of a myth?

Now, we would like to address this debate, mainly because many people think that rising damp is more of a myth and does not exist. In fact, there is a debate both on and offline since rising damp is a rare occurrence, as mentioned earlier. Then there is also the fact that the problem is misdiagnosed often by people who are not aware of what causes it or possible rising damp solutions. 

We have many underqualified and inexperienced surveyors in South Africa who often misdiagnose the issue. When you have a wrong diagnosis, it often means that treating the problem will fail.

How is Rising Damp Misdiagnosed?

The most common misdiagnosis has to be with the issue being confused with condensation as the cause. Most just label it as damp walls. However, one of the best and most reliable ways to distinguish between rising damp and condensate is to compare the amount of moisture and its content from masonry samples gathered from the mortar or the depth of the wall and near its inner surface. If surface condensation is the root cause of the problem, then samples collected from within the wall will not be damp.

Now there are situations where an accurate diagnosis of rising damp was made, but contractors often fail to treat it. Usually, it means that there was a failure to inject a DPC cream. Incorrect installation of the DPC chemical means it will not work. Incorrect installation of DPC chemicals leads to angry and often dissatisfied customers, which has meant that, at least in South Africa, the industry has suffered tremendously. It is also one of the reasons why people would rather believe it is a myth than spend money on something that does not work.

The fact is that rising damp isn’t a myth, but it affects fewer houses than you’d imagine. But for those who are affected, it is a serious issue that requires care and attention at the home owner’s earliest. It is important to get rising damp treatment right away. Qualified professionals should be hired to diagnose and address the issue accurately.

Signs You’re Dealing With Rising Damp And How to Damp Proof

As mentioned earlier, the rising damp problem is a rare form of dampness, and treating it only works if it is correctly diagnosed. That’s why we strongly advise that you get a professional diagnosis from a certified and qualified surveyor. Usually, the diagnosis will involve an analysis of the salts.

Without the experience needed, it can be hard to distinguish rising damp from various other forms of dampness like penetrating damp and condensation.

As a homeowner, you can try and examine your home by looking out for the most common signs of rising damp which include:

  • Tide marks left behind by salts.
  • Staining of the walls coverings, blistering paint, and peeling wallpaper.
  • Various types and sizes of dark patches on the walls which feel wet to the touch. However, you will want to determine if the masonry and brickwork are wet, and it’s not just wet plaster or damp wallpaper.
  • A musty smell.
  • Fragmented plaster and discoloration.
  • Decaying wood or timber like those used for the floor joists, skirting boards, and floorboards.
rising damp showing in walls outise
rising damp showing inside a house walls
,am showing problems that rising damp causes

How Is Rising Damp Treated?

In our opinion, which is also shared by many experts in South Africa, the best way to treat it is to use damp proofing injection cream which is done after drilling holes in the dam wall. You can find complete kits, and there are individual cartridges of this cream available by leading brands in the country.

treating rising dampThe way the cream works is that it has to be either hand-pumped or injected into locations or holes in the mortar. Once the cream enters the area, it will turn into a liquid, which allows it to penetrate through the bricks and help to absorb the moisture. Once it starts curing, it will turn into a water repellent barrier and stop water from going higher in the wall. It is important to highlight here that this isn’t something that everyone can and should do, it’s best to leave it up to experts like us. As mentioned earlier, incorrectly installing the damp proof course will lead to trouble later on.

The alternative to using the method above is to install a new damp-proof membrane that works as a damp-proof course. However, it is a more expensive and complicated process involving physically removing every brick around the affected area and installing the new membrane. That said, some experts believe that it is a better technique when a larger area is affected by rising damp and not just a damp wall

Addressing Instances of The Problem on Internal Walls

When you notice evidence of substantial amounts of rising damp on the internal walls, it becomes imperative to remove the wallpaper and the plaster to reveal the substrate. The same needs to be done on the external wall.

The goal is to check if the DPC has been bridged before you proceed with using the injection or injecting a new DPC. Treatment usually involves carrying out the injection process across all affected internal walls after you drill holes into strategic locations. Then you need to redo the plaster and wallpaper.

How Effective Is DPC?

In our experience, chemical injections are very effective when it comes to treating rising damp. However, it needs to be installed correctly. Formulations have over the years improved greatly, and now they (DPC chemicals) offer a long-lasting barrier. The DPC can also be used at ground level to address damp problems.

Replaster After Treating Rising Damp

After you have injected the DPC into the affected area, you will have to get the area from where the plaster was removed re-plastered. The existing plasterwork will most likely have hygroscopic salts, which could attract moisture unless it’s entirely removed. It is also important that you get the professional to re-plaster the area with a precise specification to prevent further salt contamination issues.

Final Word

Rising damp can be a major issue depending on where you live and the age of the structure. In addition to using DPC chemicals, you should also use high-quality mold and damp proof paint on the home since that prevents or retards the growth of fungus and eliminates instances of discoloration.

While paints can’t directly prevent instances of rising damp, they can help severely limit its impact on your property, especially after you have applied a DPC barrier. Some paints come with a warranty to protect your home or walls for up to 5 years against fungal degradation. It may also work well in laundry rooms, bathrooms, and kitchens. The paint is perfectly suited for commercial use, too, with the satin finish being resilient to rubbing.

It is always a good idea to call in a professional company at the first sign of suspicion. Whether you’re buying a home with rising damp or have one with the problem, a professional will be able to make an accurate diagnosis and fix the issue so that it does not bother you again.

damp inside a house wall
damp outside a wall