The Royal Household, Kensington Palace

Harrison Waterproofing is an authorised and recommended installer for the two leading methods of internal waterproofing systems in Britain.

Where the water pressure is particularly high, where noise and dust are likely to cause concern or where it’s required to retain the existing features of a building, we generally recommend a Cavity Drain Membrane (CDM) system, to control damp or water ingress.

With a CDM system any moisture is allowed to pass through the masonry. Thereafter it’s controlled by the use of a waterproof, ‘eggbox’ design, High Density Poly Ethylene membrane, attached to the masonry.

This was the case when we waterproofed stately Kensington Palace. We first begun to manage the water flowing through the cellar walls in the underground vaults.

Once an area is waterproofed, we can either render directly on to the CDM or provide a ‘dry line’ plaster finish.

Where there is not a gravity fed option, the Cavity Drain Membrane system is supported by pumped system.

Many architects now recommend the installation of a water collection channel, pictured right, which can be bedded into a preformed channel at the floor/wall angle. Holes in the channel wall allows water to ingress at this point to drain away to a sump. Rodding eyes are available to allow maintenance and inspection.

Wellington Arch

A Cementitious waterproofing system maintains a dry environment, in an underground area, by creating a physical internal barrier to damp and water. For this type of system we are authorised and recommended by industry product leaders, Sika Ltd. During this relationship we have installed the Sika water-proofing system in basements, lift pits, underground tunnels, bridges, reservoirs and swimming pools. As such, we welcome tenders for any size of contract.

The first step towards a successful Sika system is adhesion and it’s essential the substrate is suitably prepared, either by Scabbler or Bush Hammer, prior to work starting. Thereafter, if there is any likelihood of movement, we also recommend the use of combiflex movement joints around wall / floor joints. False economies here can lead to expensive problems further down the line.

Thames Wall, Rainham

Firstly, we had to cut away any affected concrete and treat the reinforcing bars.

We used specialised flexcrete repair mortar to re-instate barrier wall, stripped out the failed mastic in the movement joints and then finally the re-instatement of new expansion movement joint.