The tanking to this sunken music room for a concert pianist had constantly failed, and continued to do so despite an earlier intervention by someone else which attempted to stem the floods by the use of a combination of Bituthene and Newton 500 membrane. Having been asked to resolve this problem once and for all, and in view of the considerable volume of water coming up through the ground, I opted for a beam and block floor with a smooth screed laid to falls below.
Flooded floor above the waterproof membrane (this photograph was taken after the removal of the screed)
Beam and Block floor built over the self-draining void
Hardwood floor laid on the beam and block floor
