Membrane Systems


8mm MembraneCavity drainage membrane allows water to pass down the back of the membrane into the channel below. The membrane on the wall normally has 8mm dimples (looks like small egg boxes)

There are two main types of wall membranes these are a) standard 8mm dimple and b) an 8mm dimple with the added benefit of a lathe layer - this allows plaster to be directly applied to the membrane if the area is restricted for space or you need to match into an original feature.  If the lathe membrane is used then you need to have a good strong sub straight as lots of plugs need to be used to support the plaster.

It is important to note that the membrane is fixed using special waterproof plugs and is fixed through the membrane unlike the traditional “Tanking Slurry’s”.

Alliance uses a range of internal waterproofing products and systems, provided by DELTA, to not only stop water from entering your basement/property but also to manage and control it.

Internal ‘Type C’ waterproofing systems consist of two main components.  These are the cavity drain membranes, and the specialist drainage, such as sump pump stations, perimeter drainage channels, or 129 drainage detail.  

Internal Basement Waterproofing | Alliance

The cavity drain membranes act as the internal barrier that is wrapped around the walls laid across the floor and sealed using the Delta systems range of adhesive products.  These membranes have a studded profile which creates a cavity to allow water and water vapour to collect and drain to a drainage system such as a sump pump.

The two main types of specialist drainage systems are the perimeter channel system, and the 129 drainage detail. This is designed into the new slab using 110mm drainage pipe, with upstands, one inlet for every 12m² of floor area. The water is then drained to one of our sump-pump stations that pumps the water out of the basement externally.



Floor membranes are similar to the wall membranes but have bigger dimples normally 20mm, this allows the water to pass freely under the membrane to the peripheral channel without blocking.

It is normal to coat the new concrete slab with an anti-lime treatment before any membrane is installed.

Alliance can waterproof both existing structures as well as new constructions. Properties undergoing refurbishment frequently have basements that will need upgrading so they can become drier and then converted into the desired room.  Different levels of dryness are required dependant on what you are converting your basement into.  For example a car park may require a different level of dryness compared to a bedroom. Buildings/structures aren’t always dry, water and water vapour will always exist.

Basement Conversion | Alliance

Before you can refurbish your basement you need to have control of the moisture and water which is in the actual building structure as well as the humidity and temperature.  Each of these are a vital part of removing the dampness from your basement and maintaining a dry building.

A waterproof coating should be applied inside the walls and floors which should be done before insulation or decorating. Once the room is waterproofed/damp-proofed the air needs conditioning to maintain the right levels of humidity through sufficient ventilation or air conditioning. If this specification is not met then any moisture in the home will cause the humidity levels to rise.

Areas below ground level are prone to condensation.  This occurs on the coolest surfaces so steps need to be taken in order to prevent condensation causing problems. Alliance use the right products provided by Delta Membranes for all your needs.

Internal Basement Waterproofing | Alliance

Typical detail of our internal ‘Type C’ waterproofing system

DELTA®-MS500 on the walls fixed with Qwik-Seal Plugs, DELTA®-MS20 on the floor, both sealed with Tape and Corner strip at the joints. DELTA Drainage Channel is installed around the perimeter of the room collecting the ground water draining away to a Dual V3 Sump Pump.


Modular Drainage | AllianceIt is essential to make sure that your Type C systems and most importantly the pumps are maintained to a high standard.  They require regular servicing to ensure that the pumps do not fail and that the cavity membrane does not become blocked.

Free lime could potentially build up especially where new concrete is present in the basement construction.  It is recommended to treat this with an anti lime primer as part of a Type A system. Built into the drainage design flushing ports and access panels are to be incorporated at the required points. 



Alliance offers the full range of waterproofing products from all the main Waterproofing manufacturers: - John Newton, Delta and Basement Systems USA.

Alliance Surveyors are fully qualified and are Certificated Surveyors in Structural Waterproofing.  In addition to this they have attended training courses from the leading manufacturers in the UK and USA.