Great Portland Street, London

08 February 2021


Basement type: Refurbishment Building type: Commercial
Type of waterproofing: Type A Member: Sika 

Sika’s provision of a waterproofing solution for a high-end commercial refurbishment ensured the valuable building’s long-term protection against water ingress.

The renovation of office premises in Great Portland Street, central London involved the installation of a proven waterproof system to the property’s basement, vaults and pavement areas.

Project Requirements

Selected for the project by the main contractor, the waterproofing specialists installed the Sika 1 Pre-Bagged Waterproofing System. A strict deadline was agreed to complete the works in order to minimise disruption to business. This was hindered by a need to restrict noise levels and limit disturbance to neighbouring businesses. It resulted in installers carrying out waterproof work in two-hour intervals.

The Solution

For the waterproofing, the Sika 1 Pre-Bagged Waterproofing System was applied to the building’s main basement, front vaults and pavement light areas at the rear of the building. The system, an ingenious tanking solution, was applied across a 550m2 area. Its versatile cementitious render is ideal for new and refurbishment projects. A liquid waterproofing admixture is mixed into the render, and once applied, bonds monolithically to the substrate. At wall and floor junctions, Sikadur®-Combiflex®, a high performance and waterproof joint-sealing solution, was applied to a 190ml thickness.

Dust presented a further challenge to installers during waterproofing work. This was controlled by wetting down surfaces and installing extractor fans where necessary.

Download the case study PDF.