Basement Waterproofing/Tanking

Many properties have unused basements. In this age where space is at a premium, the cost of converting this space into a useable bedroom, office, playroom, etc is very cost effective and will increase the value of your home.

With nearly 30 years of experience in solving problems with dampness in buildings, Shaw Preservation is recognised as an approved installer of the cavity drain membranes and a member of the Structural Waterproofing Group.

Most buildings and decorative materials are sensitive to moisture. If the passage of moisture and penetrating water is allowed to continue, then defects and deterioration of the internal surface will take place.

Typical indications of moisture ingress are:-

• Plaster/render cracking or de-bonding from the substrate.
• Decorative finishes discolouring or peeling away from the plaster.
• Rotting of skirting boards, doorframes and architrave’s.
• Pungent musty odours and mould growth.

There are two types of waterproofing a basement, one is using a cemetitious waterproof plaster, the other a cavity drain membrane system. Cavity drain membranes work on the principal of allowing water to continue to penetrate the structure, but control it in the air gap, diverting it to a suitable drainage point, incorporating a sump and pump, whilst a cemetitious system is applied directly onto the walls at the point of contact.

Shaw Preservations will advise you of the one most suited to your property/ budget/ needs etc.

Cavity Drain Membranes

Membrane is fitted to the walls using specialist fixings. In some instances, a sump and pump is also installed to drain the free running water. The walls are then dry lined or plastered onto directly and the floors screeded or chip-boarded. Decorations can begin almost immediately.

Advantages:

• No preparation of contaminated surfaces.
• Quick, clean and simple to fix.
• Can be used on crumbling and painted surfaces.
• Easy to achieve a high standard of decorative finish.
• Can be decorated almost immediately.
• Helps to reduce heat loss.
• Allows pipes, electrical wires etc to be hidden.
• No water pressure build up.
• Withstands structural movement and vibration.
• Carries a 10 year guarantee.
• Guarantees can be underwritten by the GPIC (underwritten insurance company).

Sump Pumps

The sump basin is a polyethylene pre-formed chamber with a series of perforations around the perimeter. These perforations relieve the ground water pressure, allowing easy access for water to flow into the sump. The basin is commonly located into the floor sitting flush with the surrounding floor level.

The flat lid situated over the basin (which can be walked upon) is easily removed to allow regular maintenance of the internal submersible pump. The pump is positioned inside the basin and is controlled by an automatic float switch. As the water level increases within the sump, the float rises, and when the pre-sent level is reached, automatically discharges the water. To avoid any water being discharged back into the basin, a no-return valve assembly is provided. This is fitted directly to the submersible pump outlet via flexible couplings and supplied ready to accept a standard 1½’’ waste pipe. The no-return assembly has easy access for cleaning the internal value.

Cemetitious Waterproofing

Cemetitious waterproofing is a slurry mixed with water and applied directly onto prepared masonry becoming an integral part of the structure. This mix forms a bond with the masonry blocking the passage of water. This method is particularly effective for intricate structures and does not require the use of any pumps.

Advantages:

• Withstands high water pressure.
• Easy to apply suitable for complex and intricate structures.
• No sumps or pumps required.
• Carries a 10 year guarantee.
• Guarantees can be underwritten by the GPIC (independent insurance company).