Waterproofing Wisdom – Episode 01

Waterproofing Wisdom is our monthly snippet of thoughts/lessons learned/news. You can sign up here.

This past month I’ve worked on two expert witness type appointments. Both happen to be on podium decks/ plazas. Both happen to be failed renewal of waterproofing schemes. Both were procured under a traditional contract.
Both of these schemes have left the employer in a weak position where they are unlikely to have any proper recourse against the contractors/consultants involved.


Waterproofing Wisdom

  1. I think it is best to procure waterproofing as a design and build/Contractors Designed Portion (CPD) or similar such that the waterproofing contractor is responsible for the design. I believe this will reduce finger pointing in the event of a failure.
  2. The waterproofing still needs to be designed so we should expect to pay for this. Waterproofing is a complex niche profession and we want the design right. This is far more than simply placing standard details onto drawings. Always make sure that the specialist waterproofing contractor has competent in house design teams.
  3. Often the specialist waterproofing contractor is a sub-contractor. In order for the employer to have recourse we need to check more than just the collateral warranty. We need to check the scope of the sub-contractor’s appointment to ensure that they are responsible for design.

Next time

In about a month I intend to share another episode of Waterproofing Wisdom. That will focus on ‘what’s new with BS 8102’. I was on the committee that revised this guidance document and the 2022 version has just been published. I’ll try to pull out what I believe are the key changes.



Ben Hickman



hello and welcome to this the first ever issue of waterproofing wisdom my name is ben hickman and I’m the technical director of CLWand I’m hoping to share with you some waterproofing wisdom every month based on whatever it is that we’ve seen this month and what what we’ve learned and experienced so thank you for watching uh this past month I’ve been working on on two different expert witness type appointments and both happen to be on podium decks or plazas both happen to be refurbishment schemes which have failed both happen to be traditional contracts and in both situations the employer has been left in a weaker position than they should be one scheme is an eight million pound renewal of waterproofing on a large plaza and as i said it was uh procured under a traditional contract however the design information was very sparse and in reality the waterproofing supplies details formed the basis of the waterproofing design the workmanship from what I’ve seen is pretty good but the design was poor and unfortunately this has left the employer in a difficult position where they’re probably looking at facing um another renewal of this waterproofing system so that’s the same problem again now how do we avoid this sort of thing um it’s uh I guess this is the wisdom part so if you want to in if you want to procure some complex waterproofing um you really shouldn’t do it under a traditional contract it would be much better to use a with design form a contract and that’s because in the event of failure there’s much less finger pointing having said that please don’t think that you know if you go with a JCT with design or a d and b sort of contract please don’t think that you don’t need to pay for the waterproofing design that’s going to come free of charge waterproofing is complex and it’s high risk so we should expect to pay people to do it properly and in my experience this is far more than an architect taking standard details and putting them onto the relevant drawing awards proofing should be designed by competent specialist contractors with suitable in-house experience and expertise and then lastly if we want to make sure that the employer really does have recourse with the designer that’s not just a case of checking is there a collateral warranty we also need to check that the appointment documents line up so that the specialist waterproofing contractor is also appointed to do the design those are my top tips my waterproofing wisdom next time I’ll be talking about uh what’s new with bs8102 and I was involved in the committee that’s just reviewed that and it’s been published very recently and it’s going to cause some some slight changes in the basement waterproofing industry thank you very much for watching and uh if you can if you ever need anything to do with waterproofing design or consultancy give us a call

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