Basement Waterproofing

How does waterproofing work?
All forms of internal waterproofing, except cavity drain membrane systems are reliant on the bond or loading between the waterproofing material and the substrate to which it is adhered, as well as being flexible and strong enough to resist any bending stresses imposed on the structure where the tanking is holding back ground water (hydrostatic) pressure. If not, as is often the case, lateral bending stresses of the structure will crack or de-bond the waterproofing, leading to the failure of the system. For that reason we recommend that a thorough inspection and assessment is carried out by an experienced and ideally qualified waterproofing surveyor (CSSW). Our surveyors have this qualification and would be pleased to discuss your project requirements.

An internally-installed Cavity Drain Membrane system uses a completely different principle. Rather than holding back ground water, it allows water which has entered the structure to be controlled and directed to suitable drainage. A Cavity Drain Membrane system consists of impermeable studded sheet membrane which is mechanically fixed to the walls using specialist fixings and seals. The stud profile of these membranes creates a cavity allowing any water or dampness permeating through the structural fabric of the building to be isolated behind the membrane. Any ingressing water is depressurised and falls to the floor or drainage channels. On the floor the Cavity Drain Membrane is normally laid loose over the floor, allowing any water to pass under the membrane and into a drainage system, which is then discharged from the property normally by a sump pump. The Cavity Drain Membrane systems do not impose stress on the structure of the property, and has other advantages over tanking systems such as ease of access for inspection, reparability and insulation performance.

Despite the aforementioned advantages, cavity drain membrane systems alone cannot be used in all structural waterproofing/tanking situations. Cementitious and resin systems or other coatings and sheet systems still have their place, and can provide an effective waterproofing solution and sometimes are the only practical method.

BS8102 states that a drained cavity form of waterproofing (Type C) is the form of waterproofing which is least likely to fail.

See our video about waterproofing:

What are the steps to make a space waterproof?
– Inspection & Surveys
We have knowledge and working experience of most waterproofing systems in buildings and structures. In 1990 The British Standard Institute published a “code of practice BS8102 Protection of structures against water from the ground”. This publication has resulted in a major impact in how buildings should be waterproofed and caused much rethinking on the specification and extent of works now involved with the design principles in and providing a fit-for-purpose waterproofing system. Cavity Drainage systems are proving to be very reliable; indeed BS8102 states that Type C (Drained protection) “waterproofing is considered the most effective and trouble free”. It is less demanding on the structure, with improved installation procedures. However, this system is not suitable in all locations and situations, increasing the need for you to call on our broad experience and knowledge to design and install a waterproofing system you can rely on to perform efficiently.

– DrySide Surveys
DrySide carries out inspections according to your instructions on properties in relation to basement waterproofing and rising damp, as well as timber defects, such as infestations by wood-boring beetle (woodworm) and decay such as Wet Rot and Dry Rot. The purpose of our inspection is to provide a report with justification, specification and quotation for our proposed works and treatments.

The inspection is carried out by specialist qualified staff holding Certified Remedial Treatment Surveyor (CSRT), Certified Surveyor for Structural Waterproofing (CSSW), as recognised by the British Wood Preserving and Damp Proofing Association. Additionally they have passed the examinations of the School of Waterproofing, as well as many manufacturer’s exams and training courses.

Our senior surveyor alone has over 26 years surveying experience. DrySide offers an honest, balanced and informed opinion, which is not restricted to any single manufacturer or pay-related bonus/commission scheme, thereby enabling us to provide our clients with a reliable report, giving justification for our works, identifying the extent of such work and the proposed specifications, with a realistic quotation in relation to your instructions.

Will vary greatly depending on the waterproofing system being installed, generally cementitious and resin applied systems require more surface preparation, than cavity membrane systems, all will require that any structural works are completed prior to installation.
Our surveyors will advise and specify within the report on necessary preparation works.

Cementitious and resin systems are (wet trades) and are applied by trails or brushed on generally with two to four coats applied and require drying/curing time between coats in most cases
Cavity membrane systems comes on varying size rolls and are cut and fitted on site using special sealed plugs and sealing tapes.

Any waterproofing system must not punctured after application, cementations and most resin systems require some time to cure prior to applying any further decorative finishes be that plaster or paints.

Cavity membrane system can have battens fixed directly to them using special sealed plugs and plaster boarded be fixed immediately on completion of the system or a free standing stud wall built as there is no drying time required.

About Groundwater Sump Pumps

More information about Waterproofing

We've put together a range of PDF downloads about waterproofing.

About Waterproofing (British Standard)
Cavity Drain Membranes (Safeguard)
Sump and Pump Systems (Safeguard)
Sump and Pump Systems (Delta)
Fosroc® Proofex Engage
Dryside Drainage
Dryside Drainage
Cavity Drain Membranes (Delta)

Why choose DrySide for this project?
Not only will DrySide advise on the best waterproofing system to achieve dry usable space it will take into account both local and global environmental effects to the building using the best quality and environmental products used for waterproofing, from leading manufactures who have strong environmental policies in place

With over 26 years experience of waterproofing we would be pleased to discuss your requirements and provide a practical and effective solution.