Important note: If the new build is residential, and to be insured by a structural warranty provider (NHBC etc.), it is essential that the designer responsible for waterproofing (design covered by their P.I.) is CSSW qualified, and that the installation carries an insured guarantee. Always seek acceptance of design from the warranty provider at an early stage.
Trace Basements are market leaders in the provision of new build basement waterproofing design, installation and maintenance solutions for new build residential and commercial basements. You can rely on us to deliver high quality, innovative and reliable basement waterproofing solutions.
We have now completed over 50,000 surveys and 18,000 projects in our 47+ years of trading. Our expert new build basement waterproofing team has extensive knowledge and experience in successfully managing a wide range of projects. We have won 3 PCA ‘Project of the Year’ Awards; 2 CSRT awards, and 1 CSSW award.
Our clients include councils, housing associations, leading developers, Architecture Engineering and Surveying practices, major house builders and house-hold brands.
Waterproofing is an essential consideration for anyone who is building a new basement that they intend to use for work, hobbies, storage or habitable space.
If a new build basement waterproofing project does not benefit from professional and experienced oversight nor allocated a realistic budget, it could result in a cheap, inappropriate and ineffectual basement waterproofing design in seeking cut corners to save time and money. This may lead to waterproofing system failure and losses that are commonly significant for the owner of the property.
New build basements structures vary greatly from reinforced concrete, to reinforced masonry, to modern methods of construction (MMC) such as ICF (insulated concrete formwork) blocks.
Differing structures provide varied resistance to water ingress, and depending on site conditions and form of structure, Trace Basements will propose waterproofing to ensure that whatever the form of structure, high levels of resistance to penetration are provided. However to comply with BS8102 (Code of Practice for protection of below ground structures against water from the ground), we must always be mindful that any system, however carefully and professionally installed may have defects, and to design in such a way that these do not result in issue.
Where the structure is not considered to be integrally waterproof these forms will include:
Trace Basements will not employ tanking as a form of basement waterproofing to new structures in isolation. For such systems to perform when water pressure bears, they need to be completely defect free (perfect), but such assumptions conflict with the advice in BS8102.
Most new build basement waterproofing designs that incorporate an external tanking system will also include a land drain to try and de-water the surrounding ground and prevent or limit pressure against the structure. Land drains are rarely infallible.
The BS8102:2009 (CoP for protection of below ground structures against water from the ground) recommends a maintainable basement waterproofing system. However, a buried external tanking system and land drain are often difficult to maintain.
In new construction, there is a common desire to block water out and to keep the structure dry. A popular way of seeking to achieve this, is to use a barrier tanking system, which is applied to the external face of the structure, intended to keep the structure and internal basement space dry.
As stated, the 'structure' which receives this tanking can vary, but will commonly include a reinforced concrete raft foundation, and it’s more typical that the form of retaining wall built upon this can differ.
Reinforced masonry wall construction is popular because it is a simple way in which retaining walls can be constructed. This form of wall comprises two separate skins/leaves of blockwork with a cavity between. The blockwork acts as shuttering into which steel reinforcement is placed and concrete is then poured.
The limitation of reinforced masonry is that it is a permeable form of wall construction. If joints form a typical weak point to allow penetration in any structure, every mortar bed in both leaves of blockwork forms a joint, the depth of the concrete core is typically circa 150mm and often with only one layer of steel reinforcement. There is an unavoidable joint between the wall and the raft slab it sits upon and compaction of the concrete at that position may be poor, resulting in honeycombed concrete and a permeable joint.
Concrete has fluid properties at the time of pour, and in this form of shuttering has to be poured in 'lifts' or otherwise the hydrostatic pressure caused by the 'liquid' will blow the shuttering apart and allow escape of the concrete. Therefore, Once a lift has been poured, it is allowed to cure before adding more concrete over it, and this creates more joints which can allow penetration of water. The implication of this is that where applying tanking externally, you are totally reliant on that tanking, because if water penetrates past that barrier, it is essentially going to come through the structure by any available route that it can find.
The BS8102 states that a combination of Type A, B and C basement waterproofing systems is the most effective solution, but where the objective is to provide and maintain a totally dry space over the long term Type C cavity drainage is must be included and is widely considered as the most reliable form of protection.
A more reliable form of new build basement waterproofing is a Type C cavity drainage system
Type C cavity drainage systems for habitable dry space include three basic components, dimpled vapour barrier membranes lined to walls and floors, with a drainage channel system installed within the floor build-up beneath. Water can drain behind the membranes and through the channels to a point at which it can be discharged from the structure, either passively for example to low ground externally (structure built into hillside) or via a sump pump system.
Principally Type C cavity drainage basement waterproofing systems take into consideration the following points:
We promote the fact that we take total responsibility for all aspects relating to waterproofing on a new build basement waterproofing project. What this means is that we provide the complete design (backed by £2.5m professional indemnity insurance), installation by in-house staff, maintenance, guarantees, and true FCA regulated third party insurance through optional GPI guarantee insurance.
A great deal of care and attention to detail is required when choosing a new build basement waterproofing system. Failure to make the correct decisions can have a major impact on the future use of the building. Employing a waterproofing designer/contractor with the correct experience and qualifications is therefore absolutely essential.
Whether you need a waterproofing system designed at a pre-construction stage or a system designed around an existing structure, the experts at Trace Basements can design a functional and effective waterproofing system that will keep your space dry. We can design and deliver a bespoke basement waterproofing system that fits your needs on time and to budget.
Design is about following a process, refined by Trace after nearly five decades of practice. A simplified summary is:
NB: The simplified process above is laid out within BS8102 (2009) Code of Practice for consideration of below ground structures against water from the ground. This is the principle design guide employed for basement waterproofing in the UK.
If the most important element in new build basement waterproofing is design, the second most important is installation.
When constructing a structure below ground level, a waterproofing specialist should always be included as part of the design team. BS 8102:2009 highlights the role a waterproofing specialist should play in any project below ground level.
In the past traditional project specifiers such as Architects and Engineers have often taken responsibility for waterproofing design, however it is now more typical (as per the above) that dedicated specialist designers fulfil this role. Our Designers are truly specialists, working full time in this field alone. We truly believe this is the only way to safely address what can be a high risk field in construction.
Furthermore, our view is that the Waterproofing Designer/Waterproofing Specialist should be appointed contractually, and should take design responsibility on their professional indemnity (P.I.) insurance. Many waterproofing materials suppliers will seek the ‘waterproofing specialist’ role, so that they sell their materials into the scheme, but most suppliers do not want to accept design responsibility, instead placing this on others within the design team (usually the Architects).
Our in-house and directly employed staff install the systems that we design. Work will be project managed by the appointed Trace Basements Waterproofing Designer alongside our Contracts Manager, so that we maintain control of and responsibility for the waterproofing process from conception through to completion.
We do not walk away at the end of the project. Where systems require maintenance, we also provide and manage this in-house. We’re still looking after some of our early systems installed more than 20 years ago, ensuring that clients maintain dry habitable spaces.
Contact us to discuss a project, arrange a meeting, inspection, or simply send us drawings and supporting information and we can provide support and proposals.
