Damp Cellar – Treatments Available
A damp cellar being treated with Newton Damp Proof Membranes
How To Waterproof A Damp Cellar
Because they are constructed below the ground, cellars and basements will invariably have damp walls and floors. When the outside ground levels are higher than the internal ground levels – like in a damp cellar – the earth which bears against the building acts as a route for water in the ground to enter the structure.Unless you are able to remove the ground externally below the internal floor level, the damp cellar or basement is always likely to be damp, and if you require it to be a usable storage or habitable area you will need to take measures to ensure a dry internal environment.
Other Techniques – And Why They Might Not Work When Treating A Damp Cellar
Damp injection techniques will not work in a basement or damp cellar area. Whilst it will inhibit dampness rising through capillary action it will not be affective against water ingress damp. Tanking or waterproofing will be required to effectively deal with penetrating damp below the ground. Even if the adjacent ground levels are only marginally higher, dpc damp proofing sill will not be effective in treating a damp cellar. Tanking systems are designed to be applied to the structure and act to physically hold back any ingressing water and reduce levels of moisture vapour which can cause condensation damp.
Damp Cellar Solutions
When looking for a solution for a damp cellar, there are many tanking products on the market such as cementitious coatings, bitumous coatings, paint coatings and sealants. All of these types of tanking products require a good ‘key’ to the substrate to which they are applied in order to be effective. This may well require some pretty exhaustive, time consuming and often expensive preparation techniques such as needlegunning, bush hammering, hacking off plaster, raking out of mortar joints, repointing mortar joints, applying salt neutralising products etc.When applying a tanking system in a damp cellar, attention must be given to weak points of the structure where water is most likely to enter. This is often where the DIY damp proofer falls down. Following the removal of any friable and damp plaster etc, and before treating damp walls and floors can take place, it is important to heavily reinforce the construction joints within the damp cellar. In an average domestic basement or damp cellar, which typically has brick or stone walls with a continuous concrete infill slab, the weakest area is the wall/floor junction. This provides the path of least resistance for water which comes to bore around the damp cellar or basement. It is a common misconception that the water will pass through the concrete floor slab itself and into the damp cellar.
Of course it will if there is a glaring defect but if the floor slab is of a reasonable standard the water cannot pass through it because concrete is a good deal denser than water. Moisture vapour can pass through the concrete and this can exascerbate condensation and damp mould problems in a damp cellar.With the above borne in mind, water will much more easily come in at the wall/floor junction of the damp cellar, which is why is is a crucial part of any tanking system if it is to achieve its design function when tanking a cellar or basement.Another important thing to consider is the type of structure itself. Damp proofing and waterproofing professionals know that it is not a good idea to tank a damp cellar or basement structure unless it is absolutely certain that it can withstand the tensile bending stresses which can be induced on a structure when a tanking system resists water pressure.Brick and blockwork walls are strong in compression but weak in tension. Therefore when ground water creates bending stresses on the structure and causes rotation of the floor towards the wall. This movement, although in most cases small, can have a detrimental affect to any rigid tanking system and/or the structure and in some extreme cases has caused the floor slab to break its back.
Newton System 500 – The Ideal Solution For A Damp Cellar
Cavity drain damp membrane systems like Newton System 500 do not try to withstand water and water pressure in a damp cellar or basement. Instead they understand the concept that all water wants to do when it enters a structure is depressurise in an air gap.
Firstly, Newton 508 membrane is applied to the earth retaining wall areas in the damp cellar. The Newton 508 membrane is High Density Polyethylene moulded into an 8mm stud profile. The stud shape serves to hold areas of the membrane proud of the damp cellar wall to which it has been applied, which creates an air gap. The air gap is a depressurisation zone for any water entering the structure through the walls. When water enering the damp cellar under pressure finds the air gap it depressurises, loses its potency and falls behind the membrane to the wall/floor junction. At this point John Newton & Company completely advocate that as part of the Newton System 500, their Basedrain drainage conduit is layed into or onto the floor slab at the wall/floor junction of the earth retaining walls. The basedrain drainage conduit is perforated along its back edge which means that it will accept the water which enters at the weakest point of the structure (the wall/floor junction of the damp cellar) or from behind the wall membrane. In the same way as the studs of the wall membrane the basedrain provides and maintains an air gap and therefore depressurisation zone for the water entering the damp cellar. A Newton floor membrane is applied across the floor of the damp cellar, and it acts as a vapour barrier and the water collected by the basedrain is evacuated from the structure using either passive or powered methods.
Passive methods include natural drainage to an open non earth retaining elevation, existing or designed in drainage. In order to drain water from the damp cellar or basement passively, you must be certain that it is a safe drainage medium that is being connected to and if there is any risk that it will back up then another option should be chosen.
Pumping Provision An Additional Requirement When Waterproofing A Damp Cellar
Powered means of removing water basically refers to a sump and pump system. Water collected by the Newton System 500 waterproofing is delivered into a sump chamber positioned either internally or externally and then pumped from the damp cellar or basement to an external drainage source.
Newtons have several packaged pump options that will deal with clean, grey and foul water scenarios and requirements. These can be viewed here: View Newton Pumping Range
So damp coursing in below ground damp cellar and basement areas is unlikely to work and damp membrane when supplemented by drainage and used in waterproofing systems such as Newton System 500 are proven to be successful where more conventional tanking systems will fail to achieve their design function because it is often just too difficult for these types of systems to be applied 100% defect free or withstand the water pressure which comes to bore on the damp cellar.
For these reasons, many damp specialists who are approved installers of most waterproofing and tanking systems avaiable choose Newton System 500 as their weapon of choice when asked to provide a dry internal space in a subterranean building – a damp basement or a damp cellar. A damp specialist who will provide and installation guarantee and sometimes take full design liability will offer the least risk solution.
Newton Specialist Basement Contractors
NSBC Contractors can install a permanent solution for a damp cellar
John Newton & Company will always recommend when considering waterproofing or tanking damp walls, damp cellars, or wet basements, that one of their Newton Specialist Basement Contractors (NSBC) is used. NSBCs will ultimately be responsible for both the design and the installation which means that they will give meaningful, insured installation guarantees for the work they undertake and with most of the contractors having design liability insurance this also allows you to delegate the full design liability of the waterproofing aspect of the project to them. NSBCs are generally approved installers of a number of waterproofing products and as such will, without bias, put forward a design using the system or systems which they feel will be the most suitable, trouble free and effective for treating the damp cellar, wet basement, or general damp problem.
If you are having problems with a damp basement or damp cellar, and would like a recommendation for your local Newton approved contractors, then please e-mail info@newton-membranes.co.uk or phone 020 7237 1217
Toby Champion
National Sales Manager
