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Expert Advice: Signs of Rising Damp to Watch For
Key Takeaways:
Wet Patches Indicate Rising Damp: Wet or damp patches on walls, particularly at the ground level, serve as a clear sign of rising damp.
Tidemarks and Stains as Visible Clues: Rising damp often manifests as tidal markings on walls, resulting from damp evaporation and salt migration. Tidemarks are visible up to about one meter above the floor.
Peeling Paint and Wallpaper: The visible peeling of wallpaper or paint is a prominent indicator of excess moisture within internal walls.
Rising damp is a real issue that damages homes without damp proof course in the United Kingdom. It creeps up the walls until the paintwork is destroyed, the bubbling of plaster appears and you end up dealing with damp or wet walls causing an eyesore due to the excess moisture. In other words, rising damp can be a real nightmare for home owners!
And, it’s not just the appearance of damp walls, if left untreated it can cause damage to the structure of the property. The worry of living in a damaged house makes things more worrying for the home owners. But what can be done to prevent rising damp? If homeowners ignore the signs, the problems will get worse and there is very little of getting the rising damp problem resolved without a larger price tag. So, it is important to spot the signs early on.
If the home owners are aware of what rising damp exactly is, how it occurs, and what the early signs of it are, then it can be dealt with and resolved without damaging the house in the first place.
So, this article will focus on the early signs of rising damp and look into them in detail so that you can steer clear of this problem in its first stages. Let’s get started, then!
What are Signs of Rising Damp?
Yes, damp can feel as though it appears all of a sudden. But actually, it will always warn you first with some more subtle signs of excess moisture. Although it doesn’t happen overnight, it will still occur very quickly, and most homeowners do not notice it right away.
To make sure you don’t miss it, there are some signs that can let you know if moisture or damp is actually happening in your house. So, let’s see what these signs are:
Wet Patches and Excess Moisture on the Walls
If your house has the odd damp patch or wet patches on its internal walls, particularly on the ground level, increasing moisture is likely to be the cause. It occurs when moisture from the ground rises through the brick or masonry of your property’s outer walls by capillary action (when liquid can flow through a narrow space, even against gravity).
The lack of an efficient damp-proof course at the base of the wall increases the vulnerability to rising damp signs and moisture. It is critical to remember that rising damp is limited to the bottom floor and cannot develop on any other level of the home. If wetness appears on a floor higher than the ground level, it is likely that another damp issue, such as penetrating damp or condensation. (Please note, it is important to address signs of penetrating damp early too!)
Therefore, wet, damp patches on any wall of the ground floor of the house, especially on the bottom part of the wall below 150cm, can be a sign of rising damp.
Tidemarks or Stains on Walls
Rising damp is commonly visible as apparent tidal markings or patches on walls, which arise from damp evaporation and salt migration from the bottom, increasing up to around one metre above the floor.
If the tide markings on external walls are still not clearly visible, another significant clue when recognising other signs of damp on internal walls is brown or dark yellow tinged stains. Again, these stains are visible from the lowest portion of the wall to one metre above the floor, similar to tidal markings.
Notably, if the wetness on the wall exceeds one metre, it may indicate the existence of profound rising damp treatment process here. It is critical to use caution during the diagnostic process since rising damp and penetrating damp might coexist on the same area. Penetrating damp occurs when water (such as rain or leaking gutter) penetrates through the exterior walls and causes damp patches on interior walls. This is different to rising damp as rising damp occurs when groundwater rises through capillaries in masonry.
Peeling of Paintwork and Eradication of Wallpaper
The visible occurrence of peeling wallpaper or paint is one of the most visible symptoms of growing moisture in internal walls of the house. This occurrence is a direct result of the ongoing damp-related concerns, which lead to an increase in the overall moisture content of the walls.
The increased moisture levels, in turn, cause wallpaper or paint to separate from the wall surface. This separation is most noticeable around the skirting board or the lowest areas of the wall. Notably, the wallpaper also gets loose and starts peeling off slightly above the skirting board, with the edges bending away from the wall.
However, it is critical to realise that peeling wallpaper or paint alone is not always symptomatic of rising damp; it may also indicate the existence of condensation or penetrating damp concerns within the house. As a result, an accurate and complete diagnosis is required to determine the precise nature of the problem and, later, implement an appropriate repair specification to properly fix the underlying issue.
Visible Salt-Like Powder Substance on the Walls
Capillary action, a mechanism that allows moisture to migrate upward through masonry, transfers salts from the ground as it ascends the wall structure. These hygroscopic salts have the unique capacity to attract moisture from the surrounding environment, worsening damp-related issues in the walls.
The resulting impression includes the compromise of plaster. Further, when the moisture present on the wall dries, the salts emerge as a visible white coating on the surface. Therefore left untreated, rising damp not only causes damp problems but also adds the complicated element of hygroscopic salts, demanding extensive remedial actions to correct.
Bubbling of Plasterwork
If you notice flaky or bubbling plaster, crumbling plaster, or the presence of powdery deposits on the walls adjacent to the ground floor of your property, it is possible that you have a damp problem, which could be characterised as rising damp.
The entry of moisture associated with rising damp has the potential to have a negative impact on the plaster decorating your walls, causing in significant damage and weakening, and occasionally dislodgement from the wall surface.
That, in turn, causes apparent visual damage to your house’s plastered exterior walls, potentially resulting in significant financial investment for property owners if corrective actions not taken promptly.
Musty Smell in the House
Identifying evidence of rising damp within a house may can often be led by the mould and mildew growth, with one of the most apparent markers being the detectable smell of damp. Even when visible signs of damp problems are not immediately obvious, the sense of smell is typically capable of detecting it pretty quickly!
The musty smell associated with wetness is ordinarily described as an unpleasant combination of muskiness and moisture. However, if there are no apparent physical sign of damp in the house, determining the type of damp affecting the house becomes difficult, demanding the need for a trained damp specialist or surveyor.
Rotting in the House
If the problem of increasing moisture in your home goes unaddressed for an extended period of time without damp treatment, the potential consequences might include the rotting of skirting boards and flooring. This degradation is caused by an abundance of moisture, which promotes the commencement of a fungal attack on the underlying timber structures. This is often referred to as wet rot.
Rising damp, like other types of damp, has the potential to cause rotting in the timber it comes into contact with. House owners must be on the lookout for signs such as the appearance of cracks or the damage of timbers. Furthermore, visible fungal growth on skirting boards or flooring timbers will be a strong sign of rising damp in the house.
Appearance of Black Mould
The visible presence of black mould in the lower sections of your wall unmistakably indicates the presence of damp. When there is visible black mould, particularly in bathrooms, around window frames and in small kitchens, it probably suggests the presence of a condensation problem rather than rising or penetrating damp.
However, if this problem reveals itself primarily on the lower section of the ground floor walls, it is definitely suggestive of a more significant issue, such as a rising damp problem, needing a complete and comprehensive investigation.
Damaged Brickwork and Crumbling Mortar
Rising damp has a destructive effect on both the interior walls and exterior sides of ground floor external wall, where the breakdown of bricks and mortar can result in significant financial repercussions for repairing the internal and external walls.
Another sign that rising damp is damaging the structure of your property is loosening or disintegration of bricks and mortar caused by the harmful effects of rising damp creates pores, allowing more moisture to enter through the masonry. That, in turn, causes more damage to the inner walls. Fortunately, crumbling bricks or mortar may be identified through a process known popularly as fretting.
Also, a thorough examination of the cement joints is required when inspecting the exterior brickwork or masonry. The appearance of crumbling or powdery mortar, along with the collapse of the brick surface or broken brickwork, is a vital sign that the brickwork is fretting. This is another problem caused by the infiltration of moisture and salt deposits. In its latter stages, the mortar within the joints may be eradicated, sometimes completely crumbling away.
Rusting Iron or Steel
Prolonged and increased exposure to high moisture levels can cause rust to form in exposed iron and steel components. Corrosion of iron and steel fasteners may result in a significant deterioration of their structural integrity, lowering the overall security of the property.
The rusting of fasteners within the property, such as cavity wall ties, might result in a decline in their efficacy, aggravating the possible impact on the structural integrity of the entire structure. Therefore, if there’s something like this happening in your house, it might point towards the presence of rising damp.
Rising Damp or Penetrating Damp
It is critical for people to understand that signs of rising damp only appear on the ground level of houses that lack a practical damp proofing course. It is due to the upward rise of moisture from the exterior ground surface, which permeates the walls and causes damp-related difficulties in the structural integrity of the house.
If one has damp-related concerns on levels above the ground level, it is likely that they are going to need to deal with treating penetrating damp, fixing plumbing leaks, or a condensation problem.
Detecting the presence of rising damp can be difficult, especially for individuals without specialist knowledge. Many homeowners are prone to misinterpreting many damp indications, incorrectly identifying them as key rising damp signs, rather than detecting other damp types.
Before reaching a conclusion or investigating your house for rising damp, it is critical to carefully consider the following questions:
Is your plumbing faulty? Have you checked all pipes that you can for leaks?
Is your Damp- Proof Course (DPC) less than 20 years old?
Do your guttering and downpipes leak or have faults?
Are your gutters clean and free from blockages?
Is the brickwork or stonework damaged?
Do you see signs such as damp patches, stains, black mould, etc., in the house? Are they below the bottom half of the ground floor walls?
Is it a condensation issue?
What’s Next?
If you suspect that there is a rising damp issue going on in your house, call in for a damp surveyor as soon as you can. Before beginning any restoration, a damp surveyor will do a thorough investigation of the affected area. This can prevent penetrating damp and rising damp from escalating.
This sophisticated method allows for a thorough diagnosis of the specific nature of the damp problem present in your house, allowing for the creation of a personalised plan for efficiently treating the issue.
Advanced Damp Ltd. has skilled damp surveying specialists. We can perform a thorough damp survey of any property and the necessary repairing operations in a timely and cost-effective way.
Rising damp restoration treatments are chosen based on the individual characteristics of the property and the current conditions. Depending on the scenario, this may include the delicate process of stripping wall fabric, repairing the existing damp-proof course (DPC), or even installing a new DPC.
So, if your house has a potential rising damp issue going on in it, call Advanced Damp Ltd. as soon as possible.
Related Case Studies
Our recent work includes lower ground flat, Kings Cross WC1X; entrance party wall, Kilburn NW6 and bay window room, Highbury N5. Each case study sets out what the survey found and how the problem was fixed.
Lower ground flat, Kings Cross WC1X
Rising damp returned around an arch and back door despite an earlier DPC. Treated with a new DPC, waterproof render and skim ahead of a sale.
Read the case study →
Entrance party wall, Kilburn NW6
A raised front step was bridging the DPC. The party wall was treated with a new DPC, render and set.
Read the case study →
Bay window room, Highbury N5
Two areas of rising damp treated with a new DPC, waterproof render and replaster, with external defects set out for repair.
Read the case study →
Sam Fitzgerald is the founder of Advanced Damp and a working damp and structural waterproofing surveyor diagnosing and treating moisture problems in residential and commercial properties across London and the South East. He is FODCS certified (a Federation of Damp Certified Surveyor) and a member of the Federation of Damp. His hands-on work covers rising damp, penetrating damp, condensation, basement waterproofing to BS 8102, and thermal imaging surveys, and he has personally completed over 400 damp surveys across properties of every type and age. Everything he writes draws directly from jobs he has carried out. He does not write about treatments, products or causes he has not dealt with first-hand in the field.
