The Commercial Sector:

Leicester University – Structural Waterproofing


Restek’s Key Products & Services Used For:

Leicester University Ducting – Structural Waterproofing


• Site survey & testing

• Remediation process design & material specification

• Specialist resin injection to seal, bond and stabilise the corrugated pipe

• Concrete breakout & reinstatement

Project case study for Leicester University

structural waterproofing


Restek was asked by Leicester University to assess a steel corrugated pipe approximately 1.8mØ x 23m that was showing signs of persistent water infiltration, resulting in corrosion to the base of the ducting. We were asked to value engineer a solution that could be carried out in a confined space to extend the service life of the ducting by up to 25 years.

We looked at a number of options that would eliminate all points of water ingress and after the site survey we decided the level of ingress required a unique solution. Our in-house design team engineered a solution to create three effective barriers against water infiltration and to enable the ducts to remain in place while the work was carried out.

Restek recommended using a combination of polyurethane resins, modified to suit the site conditions. A waterproof foam was used for fractures that displayed severe pressing water conditions.

The benefit of using resin injection waterproofing is its ability to seal the finest of pores in building components that would otherwise enable water to find a path to the surface. This is due to the ultra-low viscosity and specially designed formula for filling voids within the building components, sealing all capillaries and pores in the injection procedure.

The resin has a controlled expansion of four times its volume compared to much higher expansion with other polyurethane resins. Due to its controlled expansion, the resin will cure to form a tough flexible resin designed to maintain a good bonding strength with the advantage of absorbing any movement without losing adhesion. 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 it’s ability to displace water within the structure due to its hydrophobic nature.


Resin Injection:


Hydrophobic water (hydro) activated water cut-off grout and foam resin based on a MDI (methylene-diphenyl-isocyanate) polyurethane. The resin is 100% solvent free and 100% solids. The cure time of the resin is adjustable with the attention of an Accelerator.

During the injection process, upon contact with water, the foam reacts to become semi-flexible. Water is not a component of the foam’s structure, so the cured material typically has a closed cell structure, doesn’t shrink or swell and is not affected by water or dryness. Depending on the amount of accelerator added, the foam reacts to form a very dense closed cell, a semi-rigid material or an open cell that is semi-flexible and provides long-term protection to the structure.

Restek’s Unique Approach 


Restek’s approach of designing tailored solutions together with our value engineering capabilities for projects ensure every part of the scheme brief from client’s expectations through to budget and programme requirements are met.

We are unique in our whole project approach as we look to engage with clients and main contractor very early (ECI) allowing Restek to value engineer a specific project solution using a variety of products and application techniques, to not only meet but exceed the client’s requirements.