Basements

Does it sound odd to suggest that allowing penetrating damp into a property may be a good thing? Well, in the refurbishment of basement areas, it is better to allow any penetrating water into the property, and deal with it on the inside. Delta Membrane Systems has a host of products that will ensure a cold, damp and dingy basement can become a warm, inviting, extra living accommodation in a property.

By creating a barrier – either on the inside or outside face of a wall – problems can arise. If work is carried out on the external (positive) face, then it is likely that a significant amount of excavation work will be carried out.

Barrier methods fixed to the internal or negative face bring further challenges in dealing with hydrostatic pressure – resulting in stresses being put on the applied materials. Any shortcomings in the quality of this installation will not take too long to reveal themselves.

With the cavity drainage membrane systems available from Delta Membranes, water is allowed into the internal face of the basement – eliminating any reliance on a chemical or adhesive bonding to the structure. And, as the membrane is mechanically fixed, any imperfections in the structure are overcome.

For this type of work Delta offers the MS-500 system which is made from high density polyethylene. While the membrane itself is just 0.6 mm thick, it features 8 mm studs on the wall-side and it is these studs that create the drainage channel. The drainage capacity is 135 litres per minute, or 8,100 litres per hour – well in excess of the likely demands.

The construction provides more than 1,800 dimples/m², giving an air volume between the studs of approximately 5.3 litres/m². This dimpled sheeting protects foundation wall waterproofing against mechanical damage – offering a compressive strength of greater than 250 kN/m².

Any water penetrating the external wall meets the plastic sheet featuring the dimples that act as a drainage channel. The natural effects of gravity take the water to a drainage channel at floor level which, in turn, is connected to a sump for collection.

Once it has reached the sump, the water is then pumped to a drainage outlet that must be sealed and have a non-return valve, or to an outside drain or soak-away.

Floor areas need an alternative product, such as Delta MS-20. This high capacity drainage membrane features 20 mm studs which offer an impressive compressive strength figure of 150 kN/m² – allowing workers to walk across without causing any damage.

Contact surface to the ground is about 130,000 mm² per m². The design ensures good pressure distribution and low point loads.

It can be used in applications where extra drainage capacity is required, such as deeper structures, or where a larger flow rate is likely.

Installation is straightforward, and the materials are easy to carry around and install. Specialist contractors are available, and Delta holds an approved list of reliable companies whose experience in this work is invaluable. They understand waterproofing, and any likely problems that might arise. Importantly, they are also able to offer the necessary guarantees for workmanship including insurance-backed cover.

It may seem odd to suggest that allowing penetrating damp to enter the building is a preferable option to creating a barrier. However, as long as that water is then properly managed – as it is with Delta Membrane Systems’ products – then there is no reason why a refurbished basement should not give a warm, pleasant environment for decades to come.

Tel +44 (0)1992 523811

www.deltamembranes.com
info@deltamembranes.com