Tanking Walls

Tanking walls in a basement or cellar refers to methods used to keep walls dry and free from problems like leaks, mould or penetrating damp.

Our guide below will outline the different types of tanking and methods to waterproof your walls before going on to describe how to tank a wall using tanking slurry or membrane. If you feel you would benefit from professional help or guidance to tank a wall in your property then get in touch with our structural waterproofing team using the button below.

Typically there are three types of basement tanking methods that can be applied to damp walls to prevent water ingress. The solution you require will depend on the extent and severity of the damp problem, and how you intend to use your underground space - whether it is simply for storage or if you want cellar tanking to create a habitable room or basement conversion in the property.

Cementitious Tanking Slurry: If the damp problem is very minimal and you only intend to use the space as a storeroom then it may be the case that the simple application of a damp proof paint or liquid bitumen masonry paint can be painted directly onto the brickwork. However, this method is only advised as a fix for very minor damp problems.

Waterproof Tanking Membrane: Utilises a system of cement-based waterproof coatings to prevent penetrating damp caused by capillary movement of water moving through earth retaining walls.

Walls are tanked in this way when there is no free-flowing water or risk of high water pressure and flooding, otherwise, it will need to be used in combination with a cavity drain system and sump pumps.

For basement or cellar conversions, or in rooms at risk of serious damp problems or flooding then we recommend supplementing tanking slurry with heavy-duty and reliable damp proofing membrane systems consisting of cavity drain membranes or mesh membrane (made from virgin high-density polyethylene) and a specialist cavity drain system where water trapped behind the damp proof sheet is channelled towards a sump pump and ejected safely from the property.

This system is commonly used for tanking basement or cellar walls to convert or renovate the space.

This section will discuss how to apply a tanking system using cementitious tanking slurry, for more information about how to tank basement or cellar walls using damp proof membranes and drainage systems, please see our tanking membranes page.

For the tanking to be most effective the walls have to be prepared properly. This means thoroughly cleaning them and stripping back any flaky or moisture and salt-damaged plaster.

You will now be able to identify any small holes or cracks and fill them in with mortar to create a smooth surface for you to paint on the first coat of tanking slurry.

To make sure the tanking solution is as efficient as possible at resisting water, then we would recommend you apply a second coat of slurry. Once this has dried completely then you are free to plaster or paint over the wall.

Without the relevant expertise, qualifications and trade body accreditations it can be difficult to identify if tanking walls will be enough to keep them dry or if you need a more sturdy and resilient solution such as the application of damp membranes, a cavity drain system and sump pump.

The surest and safest way to ensure you arrive at the right answers is to contact a team of certified basement waterproofing specialists like Rentokil Property Care and arrange a waterproofing survey where our surveyor will attend the property, conduct their investigation and provide you with a report outlining the scale and extent of the job required alongside the best waterproofing solution to keep your walls safe and dry.

Your local team of certified structural waterproofing surveyors and qualified tanking technicians are ready to get started protecting your below ground level walls.

Simply get in touch with our damp proofing team by completing the online enquiry form below for more useful advice and guidance on tanking walls and what waterproofing system is best for you.