Joined: July 2019
||Posted: 03 July 2019,17:06
I would really appreciate some advice as to how best to lower the ground level around my property. I have had differing advice from surveyors, builders and architects, and am very much "drowning in information, but starving for knowledge".
We have large concrete pavings surrounding our house, including a large patio area. The gap between the external wall insulation and the pavers varies around the house - At best they are a couple of cms below the DPC, at worst they are touching the external wall insulation which is at the level of the DPC, thus bridging is very likely. We do have some issues with damp. Options we have been presented with:
Lower and move all paving slabs so they are 150mm below dpc and away from wall insulation. Create gravel border between slabs and wall.
Lower and move slabs as above, but create french drain between slabs and wall consisting of trench, mesh and gravel.
Use an angle grinder to cut slabs or move them so they are 150mm away from wall insulation and create french drain as described above. The top of the gravel in the French drain will be less than 30 mm from dpc - will splashback still be a problem?
Just lower paving slabs to 150mm below dpc.
I don't know what the best option is. What I do know is that in my work, french drains tend to cause more problems than they solve, but this relates to historic churches which don't have dpcs.
Any advice greatly appreciated, can also provide pics if this would help?