Creating a type B integrally waterproofed basement can be achieved far more effectively, and for less cost, than by using additives and additional steel reinforcement. Type B is notorious for leaking.
We work for waterproof additive companies, repairing failures with our injection systems and cavity membranes. Waterproof additive companies often have to employ injection specialists to put right their frequent failures. Additives do not stop leaks through cracks, honeycombing and joins. The additional reinforcement and joins required by most additive companies add unnecessary cost to the construction.
If you have a leak after construction phase, the additive companies will not return until fixtures and fittings and even internal walls are removed at the clients expense. They will not accept consequential damages.
A concrete structure without waterproof additives but with well compacted concrete and no honeycombing and well prepared (scabbled) joins with correctly specified reinforcement water bars will provide a Type B structure.
A concrete structure with additives and reinforcement to BS8007, but with less than adequate workmanship in any small area will leak. Honeycombing occurs due to lack of accessibility to poker due to the amount of steel. Water bars are difficult to detail and install surface prep of joins is difficult due to steel.
The Maclennan method does not affect programing which can save thousands. Our water bars are installed into ordinary concrete to BS8102 saving at least £20/m2 on additional steel, labour and additives.
The well placed concrete is compacted correctly around the properly installed water bars and crack inducement.
The work is inspected for honeycombing and cracks by either the engineer or MacLennan surveyor. Defects are repaired locally ( as they should be anyway ) All surfaces are then coated with a crystalline slurry which effectively waterproofs the concrete and promotes self healing up to 150mm into the concrete.
For Habitable type B basements a cavity drain system is installed. This is crucial to comply with BS8102 and get meaningful 20 year guarantees and insurance that covers consequential damage.