Written by

Danny Neill

Rising Dampness vs. Penetrating Dampness: Identifying Signs and Recommended Treatments

Dampness is a common problem in buildings that can cause significant damages and pose health risks.

Two common forms of Dampness in buildings are Rising Dampness and Penetrating Dampness. Both types of dampness require different approaches for proper diagnosis and effective treatment.

This article will provide a detailed discussion of the causes, signs, and treatment options for both types of dampness.


Rising Dampness

Causes of Rising Dampness

Rising dampness is caused by groundwater or soil moisture moving upwards through capillary action and into the walls or floors of a building. It occurs when the ground level is higher than the damp-proof course (DPC) or damp-proof membrane (DPM) or when these barriers have failed.

Common Causes of Rising Dampness include:

  • Absence or failure of a DPC or DPM.

  • Bridging of the DPC or DPM by raised external ground levels, lower internal floors, or debris.

  • Missing or degraded plaster on the internal surfaces due to prolonged exposure to moisture.


Signs of Rising Dampness

Rising dampness primarily affects the lower sections of the walls, although it can extend higher up, usually no more than 1 metre high, if the moisture has been rising for an extended period. The signs include:

  • Damp patches on walls coming from ground level, usually up to 1 meter high.

  • Peeling paint or wallpaper.

  • Discoloration or staining on the wall surface.

  • A musty smell in the affected area.

  • Decayed skirting boards, floor joists, and timber.


Treatment Options for Rising Dampness

One of the most common and effective treatments for rising dampness is by means of a Damp Proof Injection System. It involves drilling holes into the affected walls at regular intervals and injecting a specialized chemical into the mortar. The chemical then spreads and forms a new DPC or DPM that blocks water movement and prevents further rising. There are two main methods for a damp proof injection system:

Chemical Injection Fluid

This method involves injecting a fluid containing silicone / siloxane based chemicals into the walls' mortar. The injected fluid then penetrates the cavities in the mortar, creating a barrier against rising dampness.

    Chemical Damp Proof Fluid System Using Triject 3


    Damp Proof Cream

    This has become a much more common and modern treatment of Rising Dampness. This method involves injecting a silane based cream-like material into the wall's mortar. The cream material spreads easily, filling the pores and cracks in the mortar, ultimately creating a barrier against rising dampness.

      Why not read our Blog on 'How To Use Damp Proof Cream'?

      Damp Proof Cream Injection Using Ultracure



      Penetrating Dampness

      Causes of Penetrating Dampness

      Penetrating dampness refers to water that seeps into the building from the external environment. It may result from poorly sealed building envelope elements, a leaky roof or defective plumbing.

      Common causes of penetrating dampness include:

      • Damaged or missing flashing around windows, doors, or roof penetrations.

      • Poorly maintained gutters and drainpipes.

      • Non-functioning damp-proof membrane (DPM) or inadequate insulation.

      • Poorly maintained masonry or brickwork.

      • Ingress of rainwater due to poorly designed landscaping.


      Signs of Penetrating Dampness

      Penetrating dampness can affect any part of the building's internal surfaces, unlike rising dampness, which typically affects the lower sections of the walls, no more than 1 metre high.

      Common signs of penetrating dampness include:

      • Stained or discolored patches on walls, floors or ceilings.

      • Musty odor and mold growth (this can also be a sign of Condensation Dampness due to poor ventilation).

      • Peeling paint or wallpaper.


      Treatment Options for Penetrating Dampness

      The treatment for penetrating dampness depends on the nature and extent of the problem. A professional damp specialist can diagnose and suggest a solution that can range from minor repairs to a complete overhaul of the building's envelope.

      Depending on where the dampness is penetrating from, Damp Proof Membranes, Water Repellent Treatments and Damp Proof Paints are often the most effective methods for treating penetrating dampness.

      Masonry Water Repellents (For Exterior Walls)

      These products are applied to the surface of the exterior masonry, where they penetrate and form a protective barrier against water penetration and ingress. Masonry Water Repellents often have varying levels of breathability, depending on the product's specifications. Why not read our Blog on AquaSolve-Pro Masonry Protection Cream?

      Application of a Masonry Water Repellent on an Exterior Brick Wall

      Damp Proof Paints (For Floors)

      Damp proof paints such as Wykamol Technoseal DPM or Wykamol EP40 Epoxy Floor System are an excellent solution, as they provide a long-lasting protective coat that prevents the ingress of moisture.

      • Wykamol Technoseal DPM is a high-performance Liquid DPM coating that is designed to protect concrete and wooden floor surfaces from water ingress, however it does not leave a wearing surface therefore requires further coverage of flooring or other protective means to ensure its effectiveness. Technoseal DPM can also be uses on concrete walls and masonry. Read our Blog on how Technoseal DPM works.

      • Wykamol EP40, on the other hand, is a two-part epoxy floor coating that provides excellent adhesion and durability on concrete floors. It is designed for use in areas subject to high traffic, and is resistant to abrasion and impact. This product is ideal for use in industrial or commercial settings, as it can withstand heavy foot traffic and equipment usage.

        Technoseal DPM Being Applied to a Brick Wall Surface


        Studded Damp Proof Membranes (For Internal Walls)

        This form of damp proofing is effective against BOTH Rising and Penetrating Dampness. This method is designed to create physical barrier that isolates the internal walls from damp substrates. It involves installing an HDPE membrane which has studs on one side to create an air gap (or void) allowing a pathway for air to circulate.

        The membrane is installed over the affected wall, secured with Fixing Plugs and sealed with a damp proof tape, usually made from butyl.

        New plasterboard can then be secured directly over the membrane, or alternatively, can be plastered directly on top of, effectively creating a dry internal finished surface ready for decoration. Read our blog which focuses on Damp Proof Membranes.

          Internal Damp Proof Membrane System Installation Using Newton 803 Newtonite Mesh



          Identifying and treating dampness in buildings require an understanding of the causes and signs of rising dampness and penetrating dampness.

          The use of damp-proof injection systems, water repellents, or studded damp proof membranes can effectively help to address these issues, preserving the building's structural integrity and creating a dry, comfortable internal environment.

          Regular maintenance and timely repairs, coupled with professional expert advice, can prevent dampness from posing significant health and safety risks.



          Copyright Infringement Of Images

          Please be aware that all images displayed on our website are protected by copyright laws, including any images acquired through licenses from stock photo providers. Unauthorized use, reproduction or distribution of these images may result in legal action. We take the protection of our intellectual property seriously and will take all necessary steps to enforce our rights. Thank you for respecting our work.


          Related Products

          On Sale
          Limited Stock
          On Sale
          On Sale