Skip to content

Project solutions

Tunnel / underpass

Tunnels and underpasses sit in wet ground, so water through joints and cracks is the main problem. Sprayed concrete, sheet membranes and injection are the usual tools.

Request a project proposal

Solutions in build order

What this project needs, step by step

Tunnel arch in rock partly lined with sprayed concrete, with a rig nozzle fed by an accelerator line spraying the rest

Shotcrete, tunnels & slope stabilisation Sprayed concrete supports tunnel faces, galleries and cut slopes and lines channels and pools. The system is a pumpable base mix with a superplasticiser, an accelerator dosed at the nozzle, and often fibres. 7 steps

Basement wall and base slab of waterproofed concrete holding back ground water, with a waterstop in the wall-slab joint

Waterproof (watertight) concrete For basements, water tanks, pools and sewage works, make the concrete itself resist water with a low water–cement ratio, an integral waterproofing admixture and sealed construction joints. This is for new pours; it cannot fix a structure that already leaks. 7 steps

Basement section with a membrane on the outside face of the wall and under the floor slab, facing the groundwater.

Basement waterproofing from outside (positive side) For new basements, or where the soil can be dug away, stop water on the face that the soil and groundwater press against. Build watertight concrete, seal every joint, coat or sheet the outside face, then backfill carefully. 7 steps

Two concrete slabs on columns with a gap between them sealed with orange sealant over a round foam rod

Building expansion and movement joints The gaps between building blocks, slabs, walls and roofs that let the structure expand, shrink and settle. They need a sealant or tape matched to the movement, a correctly sized joint and a backer rod, or water gets in and edges break. 7 steps

Wall section with water-bearing soil outside; angled drilled packers inject resin into the crack from the dry inside face.

Leaking cracks & active water seepage Cracks and holes that let water through basement walls, tanks, roof slabs or retaining walls. First stop running water, then seal the crack with elastic injection, then waterproof the surface; rigid epoxy is not used while a crack is wet. 7 steps

Cracked concrete beam with a sealed crack and injection ports, connected by a hose to an injection gun.

Structural cracks in beams, columns & slabs Cracks in load-bearing members can come from overload, settlement, corrosion or design faults, so an engineer must find the cause first. Dry or damp cracks are then bonded by epoxy injection; leaking cracks follow the leaking-cracks guide. 7 steps

Concrete beam with a square cut-out repair: cleaned steel bars coated, and repair mortar being trowelled in flush.

Spalling concrete (chhajja, balcony, beam, column) Concrete that cracks, bulges and falls away, usually with rusty steel behind it, on chhajjas, balcony slabs, beams, columns and tank slabs. This guide follows the EN 1504 sequence: remove, protect the steel, rebuild, seal and protect. 7 steps

Concrete building facade half coated with a protective coating by a roller on a pole, with rain beading off.

Protective coatings & water repellents for concrete Coatings and impregnations that keep water, chlorides and carbon dioxide out of concrete facades, bridges, car parks and repaired structures. Choose a clear impregnation, an anti-carbonation coating or a crack-bridging coating to suit the exposure. 8 steps