I am having a 100mm concrete floor laid under my carport, which is at present only dry earth.
The local builder who is helping with this claims that, in view of the fact that part of the area is very occasionally affected by a flash flood, he should not fit a dpm as this would produce a risk of the concrete raft "floating" and cracking.
I have never heard of this before. In fact the 100mm rise in height (with a slight ramp in front) may well overcome this problem anyway. And it will still be well below the dpm of the house, incidentally.
I will be keeping my classic car under there and need as dry a floor as possible. What do other members think? Would you insist on the dpm in this case?
The local builder who is helping with this claims that, in view of the fact that part of the area is very occasionally affected by a flash flood, he should not fit a dpm as this would produce a risk of the concrete raft "floating" and cracking.
I have never heard of this before. In fact the 100mm rise in height (with a slight ramp in front) may well overcome this problem anyway. And it will still be well below the dpm of the house, incidentally.
I will be keeping my classic car under there and need as dry a floor as possible. What do other members think? Would you insist on the dpm in this case?