Below Ground Waterproofing - A Guide

If you are thinking of waterproofing your property there are lots of things to consider, and you may be wondering where to start. We have put together a comprehensive guide on when you might need below ground waterproofing, the types of waterproofing and the regulations that need to be considered when designing and installing waterproofing systems.

If you wish to go ahead with below ground waterproofing, whether its a wall affected by high external ground levels, or a below ground space such as a basement or cellar, you should use a company with the right credentials and experience. Peter Cox have been carrying out below ground waterproofing for decades, with qualified surveyors and technicians working out of a network of branches, meaning we have specialists local to you.

We can provide advice and recommendations from the initial on site survey, to designing a system fit for purpose and through to installation. Our systems are designed to British Standards 8102 - the industry standard for below ground waterproofing in the UK.

Waterproofing is the process of making a structure water resistant by applying special coatings, barriers or techniques to prevent moisture penetration. This will prevent water damage from moisture ingress from outside the property, either from groundwater, rain or flooding. This therefore stops leaks and damp from affecting the internal space that has been waterproofed, allowing for a habitable dry environment. Waterproofing can be used in specific areas affected by lateral penetrating damp caused by high ground levels, or full systems can be used for below ground spaces such as basements and cellars.

Waterproofing a below ground space can add significant value to your property by creating a new habitable part of the property, perfect for a home gym, home office or extra storage.

Lateral damp penetration is the horizontal movement of water or moisture into a building’s structure from the outside. It will affect walls, basements, cellars, vaults and other spaces that have external high ground levels, or are completely below ground. Lateral moisture can move from the surrounding ground and through the structure itself.

It can cause damp and mould growth internally, leading to an unhealthy living environment and can even cause structural issues such as woodworm infestations or fungal decay.

As long as external ground levels are higher than the internal floor levels, there is a route for moisture to ingress inside the property. This can be prevented by using specialist waterproofing techniques which should extend to at least 2 bricks or 150mm above external ground levels, therefore transforming basements, cellars and vaults into dry and habitable spaces.

Waterproofing is used to make a structure impermeable to moisture ingress, so is often used for underground structures, but not necessarily all the time. In the UK there are many above ground properties built into slopes or on hillsides which require waterproofing. Waterproofing can also be used to prevent moisture ingress from above structures, often through a podium deck, like car parks, plazas and roof tops.

Common areas requiring waterproofing include:

• Basement and cellar waterproofing
• Below ground vaults
• Retaining walls
• Car parks
• Rooftop terraces
• Tunnels
• Commercial Infrastructure
• Plant rooms
• Balconies
• Podium decking

If you are considering waterproofing a below ground space, there are numerous options available, so it is important to work with a professional to fully understand the best waterproofing system appropriate for your property and intended end use.

If you are thinking about waterproofing a below ground space in your property, you need to choose a system fit for purpose. There are a number of ways to waterproof a building, but if you’re considering a basement conversion in your property, you should always deal with a professional company who will conduct a thorough survey before designing and installing the system to British Standard 8102 standards.

BS 8102 provides recommendations and guidance in dealing with moisture ingress into a below ground space. 

Peter Cox will design and install a waterproofing system to BS 8102 guidelines, made up of a combination of Type A (barrier protection), Type B (structurally integral) and Type C (cavity drained) waterproofing methods, or a combination of them.

All our waterproofing is carried out by trained and experienced technicians.

Peter Cox are approved installers of Delta, Koster, Safeguard and Newton waterproofing products. We undertake quality assurance checks from the design stage, throughout the installation and onto completion of all projects we are involved with. Where drained protection is utilised and a sump pump is recommended, we also ensure this is commissioned and signed off by an independent third party to ensure it is functioning as designed.

If you have a damp and leaky below ground space and are considering below ground waterproofing, the first step is to have a waterproofing survey carried out by a CSSW qualified surveyor. They will take the time to discuss your requirements and provide you with advice on the waterproofing process.

Our surveyors will conduct a thorough survey and inspect the below ground space and check the water ingress levels, past history, assess drainage options and any existing waterproofing systems. All our findings will be detailed in a comprehensive survey report, along with a waterproofing system designed to British Standard 8102 unless otherwise stated.

A Peter Cox waterproofing system will fully protect your internal space from water ingress and will be made up of a combination of barrier protection (Type A), integral protection (Type B) and cavity drainage membrane systems (Type C), with all works carried out by our trained and experienced technicians.

Peter Cox are the market leaders in property preservation and have branches across the UK. From our network of local branches we have a number of surveyors with the ‘Certificated Surveyor in Structural Waterproofing’ (CSSW) qualification, meaning they have the knowledge and experience to advise on below ground waterproofing.

We can work with homeowners, architects, contractors and builders to design a waterproofing system to suit your needs, helping you step-by-step from design to completion.

Our frontline CSSW qualified surveyors are supported by our national waterproofing division with decades of experience in structural waterproofing and basement conversions. All our waterproofing is carried out by trained and experienced technicians local to you.

• Peter Cox are approved installers of Delta, Koster, Safeguard and Newton waterproofing products.
• We are rated ‘Excellent’ with over 2,500 independent reviews on Trustpilot and are a Which? Trusted Trader.
• We are CHAS and Safecontractor approved and also registered as a Quality Assured Firm under ISO 9001.
• All installations that comply with BS8102 standard carry a 10-year guarantee - giving you long term protection and peace of mind.