single layer of waterproofing for raft foundation

huangyhg

single layer of waterproofing for raft foundation
hi
we have raft foundation and contractor refuse to make double layer of waterproofing under the raft
he side the high level of ground water table under the raft by 45 cm and he that that is enough
but i insist in to make two layer he ask me about the reason
but i can not answer
anyone can help
regards
check out our whitepaper library.
if it's in the contract documents (specifications or drawings), he agreed to it and has to do it.  if it's just a preference from you because you want a belt and suspenders design, he doens't have to do it.