Masonry Problem

Willmott Dixon contacted Restek to come up with a solution to the problems of water ingress they were experiencing to there lower basement car park.

On arrival we viewed various areas that were showing signs of water ingress to the lower car park and it was immediately clear that the water infiltration was due to a number of factors and that we would need to work to eliminating each potential cause.

On Further Inspection

It was apparent that the Caltite concrete slab was also showing signs of micro cracking that was due to past injections of polyurethane by another contractor. Due to this, we had to come up with solution that could not just water proof the existing slab.


To adopt a structural waterproofing injection system with the use of Webac 1660, we needed to look at encapsulating the rebar with the W1660 to stop any further channels being created.

Through our pressure injection system we were able to do this, it was decided a drilling pattern of 150mm centres that intersected the rebar at 65mm depth was to be used. Once intersected, we installed high pressure bore packers into pre-drilled holes and mechanically fixed in to place, ready to be connected to our specialist pumps.

WEBAC 1660 was also recommended for its ability to seal, bond and stabilise building components as well as its extremely low viscosity. Through our pressure injection system, the resin will begin to encapsulate the rebar. Once encapsulated, the channels that the water pressure had opened up would then be plugged preventing any further tracks being created. The resin can then begin to permeate through the finest of cracks and pores in the concrete enabling the binding of concrete and rebar back together, thus renewing the slab back to its original design specification. Once the injection process has been undertaken the resin will also provide a watertight seal to the concrete and prevent any further decay of the building components from water infiltration and frost due to the resins displacement of water in the finest of fractures in the injection procedure.

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