Waterproofing
Waterproofing is a process that ensures a structure or object is able to keep out 100% of any water that comes into contact with it. In construction, waterproofing can increase the life of common materials like concrete, iron, paint and more. Although it is not common to refer to a building as being 'waterproof' (although it would not be wrong and would be understood by most), it is more common to use the term ‘watertight’ or 'weatherproof'.
A new building will reach a stage in construction where it is made watertight to prevent water from penetrating into internal areas. Alternatively, an existing building may undergo remedial works to make its basement watertight, to prevent penetrating damp or rising damp and so on. For more information see: Damp proofing.
However, the term waterproof can be applied to particular elements of the building fabric that are designed to keep out water. For example, although high-grade concrete can be highly impervious to moisture this is difficult to achieve in practice due to a number of construction reasons. But when PVC or copper water bars are incorporated at joints (the weak points) and a waterproofing agent is added to the mix, a waterproof construction can be achieved.
Similarly, a synthetic roofing membrane may be termed waterproof not only because water is unable to penetrate the molecular structure of the material but also because it can form a continuous, seamless roof surface that can be waterproof when properly installed.
In contrast, a slate roof may be termed watertight as it will generally do an excellent job of keeping water out. However, in severe weather conditions (such as wind driven rain) it may not be waterproof since water ingress may occur through joints. Cladding systems such as rainscreen cladding may allow water to penetrate through a first layer of defence, but this is then drained away before reaching the interior.
Cementitious waterproofing is a method of waterproofing used in wet areas like toilets and bathrooms. This is a semi-flexible or rigid type of waterproofing, and material should not be exposed to weathering or sunlight.
More flexible than cementitious waterproofing, liquid membrane waterproofing is a thin coating of primer and two top coats.The liquid cures into a rubbery coating on surfaces and can provide high elongation. The durability of the coating depends on what type of polymer is used.
[edit] Related articles on Designing Buildings Wiki
Featured articles and news
National Apprenticeship Week 2026, 9-15 Feb
Shining a light on the positive impacts for businesses their apprentices and the wider economy alike.
Applications and benefits of acoustic flooring
From commercial to retail.
From solid to sprung and ribbed to raised.
Strengthening industry collaboration in Hong Kong
Hong Kong Institute of Construction and The Chartered Institute of Building sign Memorandum of Understanding.
A detailed description fron the experts at Cornish Lime.
IHBC planning for growth with corporate plan development
Grow with the Institute by volunteering and CP25 consultation.
Connecting ambition and action for designers and specifiers.
Electrical skills gap deepens as apprenticeship starts fall despite surging demand says ECA.
Built environment bodies deepen joint action on EDI
B.E.Inclusive initiative agree next phase of joint equity, diversity and inclusion (EDI) action plan.
Recognising culture as key to sustainable economic growth
Creative UK Provocation paper: Culture as Growth Infrastructure.
Futurebuild and UK Construction Week London Unite
Creating the UK’s Built Environment Super Event and over 25 other key partnerships.
Welsh and Scottish 2026 elections
Manifestos for the built environment for upcoming same May day elections.
Advancing BIM education with a competency framework
“We don’t need people who can just draw in 3D. We need people who can think in data.”
Guidance notes to prepare for April ERA changes
From the Electrical Contractors' Association Employee Relations team.
Significant changes to be seen from the new ERA in 2026 and 2027, starting on 6 April 2026.
First aid in the modern workplace with St John Ambulance.
Solar panels, pitched roofs and risk of fire spread
60% increase in solar panel fires prompts tests and installation warnings.
Modernising heat networks with Heat interface unit
Why HIUs hold the key to efficiency upgrades.

























Comments
Waterproofing is the process of making a surface or structure resistant to the penetration of water. It is commonly applied to various areas in buildings or structures to prevent water ingress, leakage, and potential damage. Waterproofing is essential in areas that are exposed to moisture, such as basements, roofs, bathrooms, balconies, and foundations.
There are different methods and materials used for waterproofing, depending on the specific requirements and the location being treated. Here are some common waterproofing techniques:
Thanks for your comment, maybe you want to create a new article covering your points above, perhaps called "common waterproffing techniques", We could then cross link it to the above. Best regards. Editor