The options for waterproofing a basement are External Waterproofing, Waterproof concrete, or cavity drain.
We do not use or recommend waterproof additives . We work on 4 – 6 failed waterproof concrete basements a month where the additive companies have left the contractor and engineer with a water ingress problem to sort out.
The major problem is that leaks occur behind finishes and so it is not possible to repair the problem without removing all of the internal finishes to establish the source of the leak.
We do provide waterproof concrete structures.
Additives fail due to poor workmanship, cracks, honeycombing, and most commonly defective joints and hydrophilic strips and water bars.
The MacLennan CrystalCoat System is applied directly after construction. MacLennan repairs all defects and waterproofs the concrete completely and effectively.
The system when combined with our cavity drain is guaranteed for 20 years.
The problem with Additives
The guarantees with these products are meaningless. They don’t cover design or consequential damages. Most of them only cover the value of the original material value. Once you exceed that value you will have no guarantee whatsoever. If a leak occurs after fit out, as it often does then you have to pay for all repairs.
Water proof additives are the most expensive form of waterproofing because of the required construction to BS8007 requiring 30% additional reinforcement. The basements MacLennan design are built of ordinary concrete to BS8110. This saves thousands on steel and makes detailing of hydrophilic strips and external water barriers so much easier.