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Penetrating damp is a very common problem that can occur around the home. Without damp proofing treatment, this can cause structural damage to affected areas, become costly to cure, and be a risk to your health.
At Cobalt Carbon Free, we have over 30 years’ experience diagnosing and treating rising damp problems. It is our job to provide a professional service to eradicate your damp problems.

What are the symptoms?

Penetrating damp shares a number of symptoms with rising damp, although water movement is more likely to spread across or outwards, rather than upwards.

  • Wet, discoloured plaster on walls or ceilings 

  • Black mould and mildew on walls or ceilings

  • Rainy weather causes patches to darken or spread

  • Peeling paint work on external walls

What are the causes?

Penetrating damp is caused by either structural issues or leaks.

These issues could be:

  • Failure of the roof or chimney - this could be missing tiles, degraded/missing bricks or pointing, or faulty flashing

  • Gutters, soffits or fascia’s - faulty seals or finish leading to water ingress

  • Internal leaks - this could stem from pipes in the bathroom or radiator

  • External walls - cracks, missing or old, porous mortar or bricks

How do we treat penetrating damp?

Phases Involved:


  • Phase 1 - Preparation
    Inspection of all rainwater goods to ensure they are fit for purpose. Clean, repair or install drains as required to carry away surface water. Thorough inspection of the roof line, brickwork, pointing, chimney and any flashing detail around the property. Where reported, the necessary repairs will need to be made to the suspect details. Re-pointing, re-facing brickwork, roofing and flashing must be completed before application of waterproofing repellents/ membranes, wall insulation (internal/ external walls) or re-rendering.


  • Phase 2 - External Waterproofing Repellent Spray Systems
    Waterproofing masonry liquid penetrates brick, stone, concrete & cement. It creates a long lasting water-repellent breathable barrier. Prevents penetration of rain, the risk of water damage & spalling caused by frost is minimised.


  • Phase 3 - External Waterproofing Membrane Systems
    External waterproofing systems, combine a primary and secondary waterproofing system along with a priming stage.


  • Phase 4 - Priming Stage
    Priming involves applying a specially-designed spray to the external structure, the primer narrows the masonry pores, creating a water-repellent surface. The chemical design ensures a bond with the waterproof coating used in the primary waterproofing stage.


  • Phase 5 - Primary Waterproofing 
    Primary waterproofing involves applying a waterproof material directly to the external wall. The substrate is treated with a waterproofing compound. These specially-designed coatings have a high compression strength and are water tight even under aggressive pressure.


  • Phase 6 - Secondary Waterproofing – Cavity Membranes 
    An external cavity membrane can also be installed, which works as a drainage system. By employing the above external waterproofing system, you have both a primary and secondary waterproofing barrier. Combining these methods reduces the risk of defects. Both methods are also highly flexible - during building settlement or movement, the external masonry waterproofing moves with it and maintains watertight integrity.


Wall Insulation

Solid Wall Insulation systems are specially designed to be installed on solid wall construction. These systems provide an insulating barrier against the climatic elements. 

Types of wall insulation systems used are External Wall Insulation, Internal Wall Insulation, Hybrid Wall Insulation and Cavity Wall Insulation. All systems play a big part in resolving penetrating damp in houses and buildings. We would always recommend looking into wall insulation as an option alongside damp-proofing a property, as it increases the thermal efficiency of your property, resulting in lower energy bills. We can also provide you with a free wall insulation survey. 

Find out more about this in our HOME INSULATION section. 

If you are interested, please don't hesitate and CONTACT US now to arrange a free consultation with a member of our team of experts.
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