citizen m hotel london

Case Study / Waterproofing 

Citizen M Hotel, London

Waterproofing basement level to a hotel in Westminster

Citizen M

Dutch Hotel chain Citizen M has opened its 4th hotel in London. The 11-storey hotel was completely rebuilt after the demolition of former Press Association offices in Westminster. The new trendy hotel is located close to Buckingham Palace and Victoria Train station.

Even though the upper storeys were built new, the existing basement of the building remained, and it needed complete waterproofing with a system that was failproof, could be remediated if needed and serviced to provide longevity.

Successful contractor Gilbert-Ash contacted MacLennan for our waterproofing design. They had worked with MacLennan on very large projects before and were looking for a waterproofing specialist to take responsibility, design liability for the waterproofing system, and have an appropriate professional indemnity cover specifically for waterproofing.



citizen m hotel london


MacLennan was delighted to offer our Waterproofing system and take on full design liability on this project. The large, existing basement needed two forms of waterproofing. Our Crystalline Slurry system Crystalcoat was sprayed on the internal walls of the basement - This waterproofing system repairs any defects in concrete that could potentially let in water.

According to British Waterproofing Standard BS8102/22 "Consideration has to be given to form and feasibility of repair after construction and after finishes are installed."

This is why the Cavity Drain system was installed on floors and all the way up to the ceiling. This system can be serviced, and any potential problems can be resolved even before they have become an issue. Any water would run down behind the membrane, into a cleverly installed channel and then into a sump where it gets pumped out and away. Cavity drain system is a serviced system which is a huge benefit to the client because it keeps the installing contractor involved and responsible. It can pre-empt leaks and stop them from occurring, unlike all other waterproofing where the first sign of a leak is water or dampness on finishes which is often difficult and expensive to trace and resolve.

Using this system, the internal walls of the basement remain completely dry for Grade 3 basement which was needed in this project. Damp proofing membranes were also installed where necessary and detailed waterproofing was applied to all service entry points, which tend to cause a lot of issues if not detailed and waterproofed properly.


MacLennan installed a fully compliant waterproofing system in the basement of Citizen M hotel in Westminster. The work was carried out in the agreed time frames and within budget.

MacLennan guaranteed the work, and it was all covered by our 10 million PI.

Photos by MacLennan, Gilbert Ash

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