When visiting potential clients at home we get asked many questions regarding the method of waterproofing that we might use to protect their awesome new basement conversion from the ingress of water and moisture.
Keen to answer some of the most common questions, THINK BASEMENT has teamed up with Mike Vernon, a structural waterproofing consultant with DELTA membranes, to offer some great guidance on what you need to know about some of the best waterproofing methods available.
Why is my basement damp?
Dampness in basements is usually caused by hydrostatic pressure in the ground, which means the pressure of water in the ground coming to bear upon the basement walls and floor. Dampness can also be caused by condensation. Unconverted basements rarely benefit from adequate heating and ventilation so “stale” cool moisture laden air comes into contact with cold surfaces causing condensation on them.
How can I stop the moisture entering my basement?
There are two main systems which are designed to stop water ingress into basements. Delta Type A systems are barrier systems which key to the structure, designed to block water out forever. Delta Type C systems (Known as cavity drainage systems) are dimpled membranes applied to the internal face of the structure where the aim is to manage and control water behind the membranes, diverting it to a Delta Dual V3 sump and pump system with high water alarm and battery backup.
What are the benefits of each system?
Delta Type A barrier systems are generally more appropriate for new build schemes where they can be applied externally. This means they are pushed onto the structure by water pressure. However, once back filled it is difficult to access them for repair or maintenance. Where Type A systems are installed on the internal face, the “key” they form with the structure is vital, so the structure needs to be of very high quality and mechanical strength, otherwise failure will result. There is a very high emphasis on “perfect” workmanship and no penetrations are allowed because of the premise that the system is constantly resisting pressure.
Delta Type C cavity drainage systems rely upon the structure slowing down water ingress to a manageable level and dealing with water as it comes through by controlling and draining it away. Delta also specialises in Type A products designed to improve the integral water resistance of the structure. The Delta system is inherently safer because the Delta “System 500”membranes are point fixed using sealed Delta plugs, can cope with movement, penetrations, and the quality of the substrate is not so important. Type C systems rely on gravity drainage or sump pump systems. Delta Sump pumps are highly developed, reliable and safe, with additional features such as Delta Dual V3 pumps, UPS battery backup units, high water alarms and textmax remote notification systems.
What to consider when thinking about my conversion?
Firstly, you need to consider what type of waterproofing system will be safest, because everything you put into the basement, including services, finishes, fixtures and fittings will need to be kept dry. Delta Type C cavity drainage systems are usually better for domestic basement conversions because they are very versatile and finely tuned and less reliance is placed on the quality of the existing substrates because cavity drainage membranes do not need to chemically “key” to them. Give consideration to using Delta Type A cementitious products such as Delta Koster Repair Mortar Plus and Delta Koster NB1 Grey in depth crystalline slurry in terms of localised measures to improve the integral water resistance of the structure first.
It is important that suitable environmental controls (heating and ventilation) are designed and installed to avoid issues with condensation. A specialist basement conversion company such as THINK BASEMENT can advise you on these.
If you are seeking Building Regulations Approval, your Local Authority will be able to advise on considerations such as fire regulations, means of escape, conservation of energy requirements, acoustic issues etc. It is a good idea to seek an informal meeting with your Building Control Officer first, prior to making submissions, in order to seek an opinion regarding what your Local Authority would like to see.
What to look for when choosing a contractor?
Look for a specialist basement contractor who specialises in the installation of Delta systems. There are industry specific qualifications too, which the contractor may hold or may be in the process of attaining. Delta products and technical backup are second to none, so you may be assured you are in safe hands when choosing a Delta system.
What to ask a potential contractor?
- Do you specialize in Delta systems?
- What industry specific qualifications do you hold?
What impact on my designs might waterproofing systems have?
Delta systems are completely compatible with installation of internal finishes and services. Delta Membrane Systems Limited have scrupulously developed these and perfected them over time, so they are complimentary to both a variety of structures and allow you complete freedom to choose the fixtures and fittings to give you the basement of your dreams.
THINK BASEMENT and DELTA MEMBRANES are happy to be working together to provide you with all of the information that you will need regarding your basement conversion project. As part of the design process for your basement conversion, specific specialist attention will be given to the design of your structural waterproofing system to ensure that your basement remains a dry and pleasant environment. DELTA consultants will even visit your basement project to ensure that the fitting of their products are to the highest standard, giving you extra peace of mind. All of the technical specifications for DELTA products can be found on their website or provided by THINK BASEMENT during your design phase.
You can find DELTA membranes online: www.DeltaMembranes.com or contact us: firstname.lastname@example.org or 01992 523 523.