A Perfect Solution For A Leaking Basement Car Park

Background To Case Study

Timberwise were contacted by a commercial customer who was experiencing severe water ingress to their basement car park. As further damp related problems progressed, it was essential that the source of water had to be stopped, and the problem rectified, this would ensure the property would not suffer any costly damage.

Our Findings

Following a survey, Timberwise identified the source of the water ingress:  the floor slab was cast on to a permanent metal formwork and leaks were found at the edges, particularly where the terraces abutted a concrete piled wall and where there was a change in levels. Our surveyors also identified a sticky sheet membrane seen over the terrace decks, this provided evidence of previous failed remedial works.

The floor slab was laid level and the existing drains were only collecting surface run-off.  As a result, water was ponding on the sheet membrane and running to the edges.

 The works will improve the environment for users of the car park and eliminate the risk of damp related problems.””

Steve Montague, Waterproofing Specialist

Our Solution

Timberwise proposed that the terraces be stripped of pavers and that the facing bricks and concrete infill were to be removed. Once this was done, a screed laid to a 1:80 fall toward the apartments could be laid. Our waterproofing solution consists of a liquid applied hybrid bitumen and cement coating to be trowel applied across the screed and into the floor to wall junction.  The coating was flexible and tough when cured and could be applied to damp substrates.

To protect the primary waterproofing layer, we then proposed that a geotextile covered horizontal cavity drainage layer belaid. This would direct water to the edges, where it can be drained off and act as a sound base for paving sand etc. To collect the water we used an ACO free deck drainage channel. This has entry slots in the side as well as the usual top grid allowing free flowing water to enter the channel.

Need help with waterproofing?

If you suspect you have a damp problem in need of treatment, please contact your local Timberwise team on 0800 288 8660 for advice or to arrange a survey. Alternatively, complete the  on-line survey request form to arrange a surveyor to visit your property.

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