waterproof concrete

Waterproof Concrete.

  1. You buy the readymix concrete.

  2. We treat it when it arrives on site.

  3. We supervise your pour.

  4. You pour it, compact it and cure it.

  5. We repair any visible leaks later free of charge. But no one had any visible ingress of water during the past 6 years.

  • We supply the necessary chemical to make your concrete completely waterproof.

  • We supply the supervision to ensure good practice and avoid mistakes.

  • We hire you vibrating pokers that are powerful and work properly.

  • We will repair any visible ingress of water later free of charge.

  1. £29 per cubic metre of concrete treated.

  2. £300 a visit supervision and training.

  3. £40 poker hire. You pay only for what you use. We bring a spare.

  4. Fibreglass threaded rods and nuts: £3.50 each 1m rod and £2.00 each nut. Leave no holes, leave no leaks.

  5. We repair any visible leaks later free of charge.

That means we are guaranteeing the workmanship of people who do not work for us, as long as they do as they are told, obviously.

  Please note. The author acknowledges all the trademarks it mentions on this site.


Phil Sacre

Basement Expert

07773 377087



We are different.

We waterproof the actual concrete you use on site, we supervise to prevent errors and we often got samples tested at the lab to prove you use completely waterproof concrete.


The choice is:

Do you carry on using expensive products because they have BBA certificates despite the BBA certificates proving nothing?

Or do you use us to supervise and avoid all the causes of leaks and we get your concrete tested and prove you used waterproof concrete?


We are different because:

Following the revelation that the cladding sadly used on the Grenfell Tower had a BBA certificate and had passed a BBA fire test, we analysed the BBA certificates of all the well-known brands of water-resisting admixtures: e.g. Caltite, Pudlo, Sika, BASF, Xypex and Kryton.

Analysis of their BBA certificates revealed that all of them either had not tested readymix concrete or do not work.

Most of the admixtures were not tested in site concrete and do not waterproof either.

Since then, April 2018, more revelations have come out regarding Grenfell,
including a report by the Association Of British Insurers
describing some UK testing as 'utter inadequacy' .

In December 2017, Dame Judith Hackitt said in her interim report that the regulatory system, including building regulations, was not fit for purpose.

In her final report, May 2018 , she said the following:

" The current system is far too complex, it lacks clarity as to who is responsible for what, and there is inadequate regulatory oversight and enforcement."

What I am trying to explain is that BBA certification seems to be at the core of passing the buck of responsibility. The experience of Grenfell cladding and water resisting admixtures for concrete (and anything that swells in a concrete joint or against a concrete wall) is that virtually useless products get a certificate in exchange for a huge sum of money and then specifiers, trying to avoid responsibility in the way Dame Judith Hackitt reports, choose a product with a BBA certificate - and bags of sand, waste or just a bit more cement are sold for 100 times cost to contractors who blindly do what they are told, and
" The current system is far too complex, it lacks clarity as to who is responsible for what, and there is inadequate regulatory oversight and enforcement.".

Specifiers specifying Caltite, Pudlo, BASF, Sika, Xypex, Kryton etc. are passing the buck choosing products with a BBA certificate yet not reading and fully understanding those certificates, because every one of those certificates contains the information that every one of those water-resistant admixtures for concrete
  1. Was never tested in the concrete that will be supplied to site.

  2. Did virtually nothing to improve the water resistance of concrete (used beneath ground).

  3. Sells for outrageously more than it costs to produce.
Two out of three apply to all of these BBA certified products. All 3 apply to most of them.

Cherry picking more from Dame Judith Hackitt's final report

" The new regulatory framework must be outcomes-based (rather than based on prescriptive rules and complex guidance) and it must have real teeth, so that it can drive the right behaviours," the report says. "This will create an environment where there are incentives to do the right thing and serious penalties for those who choose to game the system and as a result put the users of the 'product' at risk."

" An outcomes-based framework requires
people who are part of the system to be competent, to think for themselves rather than blindly following guidance, and to understand their responsibilities to deliver and maintain safety and integrity throughout the life cycle of a building."

I have been explaining on this web site since 2013 that the products I list do nothing of value relative to their cost and those suppliers make a fortune from BBA certificates that are worthless yet implicitly trusted, demanded even, by the likes of NHBC.

Anyone who understands all the sources I quote ought to understand they are part of
people who are part of the system to be competent, to think for themselves rather than blindly following guidance, and to understand their responsibilities.

  1. The specifier, surely, must now first evaluate what he specifies.

  2. The contractor, surely, ought to question large sums of money spent on something he knows will not work.

  3. The client, surely, from now on will want to take an interest in some of the expensive products he is expected to pay for.

Dame Judith Hackitt said that "The new regulatory framework must be outcomes-based".

We have already been taking this approach since 2013.

Throughout the EU, concrete is made to BS EN 206-1 and hardened concrete is tested to BS EN 12390.

Part 3 is the test for compressive strength.

Part 8 is the test for impermeability.

Your engineer will specify C35 or C40 etc.. That is the compressive strength of the concrete and part 3 is the test to prove that your concrete is adequately strong.

To be classified impermeable, depth of penetration of water under 4 bar pressure maintained for 96 hours must average 20mm or less.
We have had many successful tests for compressive strength and water permeability under pressure to BS EN 12390 parts 3 and 8.

Click on either image below to see two original test certificates.

concrete compressive strength report to BS EN 12390 3                        concrete permeability report to BS EN 12390 8


The choice is:

Do you carry on using an expensive product because it has a BBA certificate despite the BBA certificate proving nothing.

Or do you use us to supervise and avoid all the causes of leaks and we get your concrete tested and prove you used waterproof concrete?


The concrete mix you will need to buy is
  1. P350. This means 350kgs of cement per m³.

  2. CEM 1, pure OPC, or pure OPC and a blend of GGBS, slag.

  3. Over-sanded for pumping.

  4. Target slump 60mm.

  5. No other additives. Tell the readymix concrete supplier you are having a powerful plasticiser added and mixed in on site.

  1. You order and pay for the concrete.

  2. You pay us for threaded rods, nuts, waterproofer, training, supervision and poker hire.

    Our products and services ensure complete success. If you accept our methods and buy all we recommend you get the free leak repair guarantee.

  3. You pay us for testing to BS EN 12390 if you wish. £780 including VAT at the lab, mould hire etc..

  4. Note.
    In hot weather, or if the concrete needs to make a long journey, CEM 1 pure OPC can set too fast to get a good finish. OPC blended with GGBS will give you more time, though in most cases you will not need it.

    Most projects do not need sulphate resistant concrete. If your does, CEM 1 with this much cement is usually resistant to DC class 2. A GGBS blend might be completely resistant to DC class 4. Check with your readymix supplier.

In 2011, the new edition of a long-respected university text stated more clearly than ever before that completely waterproof concrete could be produced without admixtures.

"concrete with a low water/cement ratio ... make the capillaries discontinuous"
Neville, A.M. (2011). Properties of Concrete. 5th ed, p330. Harlow: Pearson Education.

In 2013, the UK's Concrete Society published a report by a working group of 18 members, experts in their fields, that states:

" water/cement ratio .... primary measure of water penetration and hence the durability of the concrete."
The influence of integral water-resisting admixtures on the durability of concrete. P36. Concrete Society. 2013.

The Concrete Society had the idea to plot the various data on BBA certificates onto one chart. I have plotted the same data here, as well as a few educated guesses where marked.

from Processes, water retaining BS EN 12390 8   Here I have plotted the before and after figures for compressive strength and water permeability from the BBA certificates I found for water-resisting admixtures for concrete.

What is striking is how varied the results for concrete without admixtures and how limited, in comparison, the benefit of a water-resisting admixture.

Some data was missing, such as Caltite compressive strength test results, so I have made up missing data with my educated guess.

This chart proves how little difference all the water-resisting products make, compared to the huge difference that a better concrete mix design can make.

The 'active' ingredient in Xypex, Krystol and Triton is only OPC. Cement. At about 100 times the usual cost.

If you click on the chart it will open in a new window so you can print it.

Have BBA conned you and not tested any of these concrete admixtures on site concrete?

To pump any concrete on site it needs a slump of at least 70mm. But the workforce would complain if the concrete was that stiff and add water (which would ruin any waterproofing and void any warranty) so concrete used on site needs a slump of at least 100mm.

But as this chart of data from the various BBA certificates shows, most brands seem to have cheated in the lab, proving that they did not test concrete that would be used on a building site.

These are the quoted figures on these brands' BBA certificates for the slump in the concrete with the admixture after 30 minutes, which is about how long a truck takes to batch, drive to site and manoeuvre into position. I have also put the cement content for each and for C35A.

Pudlo Sika BASF Xypex Kryton Krystol KIM C35A
45mm 40mm 135mm 35mm 45mm  
350kgs 350kgs 350kgs 325kgs 325kgs 325kgs

Reminder. BBA testing of Caltite did not make any concrete more resistant than a plain structural concrete, neither did they quote as many figures on their certificate as the other brands shown above.

I used to buy from BASF before I went to Asia and bought the best available there. In my opinion, the slump figure for BASF - the only one tested in concrete that could be used on site - supports the science that a quality plasticiser is all that needs adding to high quality concrete to make it waterproof.

Caltite's guarantee, you will find one pictured on this web site here, guarantees that if their product fails they will put things right (but only to the value of their product).

But what does their product do? They don't say anywhere. Therefore no one could sue.

They seem to guarantee only the product but they promote 'the system'.

'The system' includes concrete with extra sand and cement and less water. So 'the system' will work because the concrete works.

Specifiers seem led to believe that the Caltite rep on site supervises.

But on site the rep makes the foreman sign a disclaimer saying the Caltite representative was not there to supervise and Caltite is not responsible for workmanship.

Most specifiers think that the only way to get anything close to supervision is to buy a BBA certified water-resisting admixture.

But you shouldn't be fooled that you will get supervision, or by the bogus guarantees that come as well, just because a product has a BBA certificate.

We supply supervision and vibrating pokers that really work well for an extra cost. That way you know Supervision and good compaction will happen.

Please go the Basement Expert web site for details of the threaded fibreglass rods and nuts.

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