Waterproofing a commercial basement in Highgate

We received drawings from a main contractor, who was developing a new housing block in North London. They had a large basement which required waterproofing to a ‘Grade 3’ (dry) environment.

The construction has reinforced concrete walls and floor with an internal space above.

As with most concrete structures and despite the implementation of a ‘Type B’ (Integral waterproofing) system, water was leaking through the construction joints and tie bolt holes.


Sovereign used a cavity drain membrane system from Newton Waterproofing, which enabled the channel to sit on a level slab using closed cell insulation to infill the space between the channels. 

The quality of the concrete and openness of the work area allowed for a speedy installation. The main advantages of using concrete (when placed well) is that, by design, the structure is well equipped to resist the passage of moisture into the internal environment.

Therefore with minimal preparation, membrane could be installed to the walls and floor, then follow-on trade could come in soon after.

Project Requirements

There weren’t many challenges with this project. Working with a concrete structure is incredibly beneficial. The most difficult aspect of this project was parking as with most London boroughs!