I have spent my entire working life dealing with basements and particularly in addressing failed waterproofing systems of all types. I hope to provide some useful information, to those that might be interested in, affected by, or care about basement waterproofing issues.
The 90’s were great; it involved most of my time at school, then starting and completing both college and university, with a lot of building site work thrown into the mix during the ample holidays that you enjoy as a student. But what a time to be that age, and in Manchester…
Anyway, back then we, and I say ‘we’ but essentially I mean George/my M.D./Dad, was moving away from the traditional multi-coat cementitious tanking render systems, towards cavity drainage waterproofing systems, generally using three components:
At present we are completing a remedial waterproofing scheme within a residential basement, where we are installing cavity drainage waterproofing to address issues of penetration past the internal cementitious slurry tanking system.
Nothing particularly unusual about that, but it is significant to me at least, in that this takes our turnover remedying failures in that specific slurry tanking product, to over £250k excluding VAT.
We seem to be remedying more and more failed podium deck waterproofing systems and so I thought that this topic would make for an interesting post.
The examples all involve apartment buildings with basement car parks beneath, where that basement extends beyond the line of the structures over, with this creating external decks subject to rainfall.
Even in basement car parks where a degree of seepage is considered to be acceptable (BS8102 grade 1 environment), penetration through a soffit can be an issue since water moving over or through concrete (cracks etc.) leaches free lime, which is damaging to paintwork (as below) and so the space may not be fit for purpose as a result.
Firstly, apologies for the overly dramatic title but hopefully this will provide a useful example of the implications that a basement conversion can have on a property, where the work and guarantees which stand behind it are questionable.
Soakaways are a means by which surface water (roof/rainwater) can be discharged into the ground. These have a range of benefits, in that they deal with surface water where there is no access to mains drains, they place a lesser demand on those systems if they are present, and they can provide a saving on your utility bills versus discharge into a mains system. They are commonly employed within new-build developments and we often see them.
The design of soakaways is a science in itself and should be undertaken by a suitably qualified Civil Engineer. It is not the design of soakaways that I want to comment upon, but their use in association with basement waterproofing systems, and implications upon the waterproofing where soakaways do not function as intended. Continue reading Soakaways and Basements, not Always a Good Combination.→
This is an article written by David Bucknall, Technical Director at Newton Waterproofing Systems. I’m a fan of Newton’s, in part because of the product range and also because most of the staff have a background in contracting (in waterproofing) and so they understand what it is like at the sharp end, implementing works and then promising clients protection for a decade.
As intimated in this post, British Standard 8102 Code of practice for the protection of below ground structures against water from the ground, is the primary design guide which we and others rely upon in our work designing and installed structural waterproofing systems. As an ‘approved code of practice’ it has an elevated legal status versus other design guides and hence its importance.
One of the key considerations listed is that of defects and remedial measures. In essence designers should assume the risk that any given waterproofing system might not be installed defect free, with risk of defects being associated either with workmanship or the products installed. Continue reading Defects, Defects and Defects (BS8102).→