The Marnham Building, Mill Hill School

The Marnham Building at Mill Hill School was refurbished as part of a major project being carried out at the school by Mansell. The basement of the building had damp problems with the floor slab, the previously painted brick walls and the concrete filler joist soffit below an external pedestrian walkway. The refurbishment of the area was planned to provide a future teaching facility.

Following opening up of the soffit and investigation we were awarded a design and build contract for the repair and strengthening of the defective filler joist steels and concrete surround. Steel joists were grit blasted and 55m of weber.tec force carbon fibre reinforced plates were bonded to the underside with their EP structural adhesive.

Repairs were completed with weber.cem hand applied polymer modified repair mortars. The external walkway above was treated with a Tor coating to provide a waterproof non-slip membrane.

Grit blasting techniques were used to remove defective coatings from the basement walls, to etch the glazed brickwork beneath and to also prepare the floor slab prior to the application of a waterproof membrane.
In addition a chemical dpc was injected to the internal walls using Remmers Aida Injection Cream and defective pointing made good with a polymer modified repair mortar to provide a suitable background for the waterproof render treatment.

15,000kg of Weber Motex Dry-rend waterproof render, consisting of bonding coat and 2 further coats to a total of 12mm, were applied to the prepared surfaces with a fillet and mastic detail at the floor junction.

Finally the prepared floor was treated with 2 coats of RIW Toughseal and a self-levelling screed to protect the membrane.

The Main Contractor’s finishing trades then completed the conversion to classroom conditions with new blockwork and plaster walls and joinery works.

The Main Contractor’s finishing trades then completed the conversion to classroom conditions with new blockwork and plaster walls and joinery works.