Mythe WTW

Service Reservoir Repair & Refurbishment

The project was carried out over a 14-week contract period, which included the essential survey, repair and waterproofing of a 2 million gallon clean water tank at Mythe WTW for Severn Trent Water. Due to the time of year and low temperatures, the entire tank was protected by a heat and moisture controlled air-conditioned marquee.

The existing tank roof landscaping, grass and failed membrane was carefully removed, by lightweight machines due to limited weight restrictions, followed by thorough clean by 7000psi pressure washer to remove existing laitence and remanence of primer. Thereafter, the substrate was repaired locally, all construction joints formed, filled using flexible poly-sulphide mastic and overbanded with flexible sheet banding Fosroc Proofex.

Due to standing water ponding issues, the perimeter edge beam upstand along one elevation was carefully removed, reinforced, tied down and concrete carefully profiled to provide natural water run-off.

Upon completion of all repairs, the entire roof surface and associated perimeter wall downstands were encapsulated with the Fosroc Proofex sheet waterproof membrane system, covered over and taped with Sheetdrain 80 cavity, geotextile protection layer followed by backfill of aggregate.

Hatch access points were also waterproofed using a Fosroc epoxy membrane system with UV stable coloured finish.

Under confined space permits and controls, internal concrete floors, walls and columns were surveyed with isolated concrete repairs carried out using DWI approved materials.

Wall and floor joints were carefully prepared and overbanded using the Sika Combiflex waterproofing banding system.