I've posted a couple of things about trying to reduce some of the dampness in a lean-to utility room in a Victorian terrace. There is an outrigger kitchen (suspended floor) then a step down to the lean-to utility room which has a concrete floor. The kitchen wall had an injected DPC before I moved here and the documentation from that says that they had to cut away the render at the base as it was right down to the ground. The exposed brick is now painted in some thick black paint of some sort. A little bit of the interior plaster I can see in the utility room suggests it may have been cement tanked.
The whole garden is, sadly, covered in concrete which slopes towards the house. I think someone has tried to aim it towards the drainage grate but hasn't been completely successful. Ground levels are just below the airbricks under the kitchen floor, but because there is a step down to the utility room then the outside levels aren't all that different to the floor levels in the utility room. In the very heavy rain last week you could see water ponding against the house.
I had a quote for a french drain a few years ago, but I was nervous because my understanding is that houses in this area often have very shallow foundations and I didn't want to start messing with how water was moving there. I've recently had a builder suggest that a simple and cheaper option, at least initially, would be to cut a channel in the concrete around the perimeter, remove 100mm of hardcore/soil - whatever is there I suppose - and replace with gravel. I was hoping to get people's views on this approach rather than using a formalised french drain.
My understanding is that a french drain actually takes the water into a perforated pipe, whereby potentially drying the soil immediately adjacent to the house. It should be installed x distance away from the foundations, but I don't know if that entirely mitigates that risk. In this proposal, more water would surely drain downwards, but it would just percolate into the soil rather than being actively taken away.
They haven't specified the width of the channel that they propose. As the rest of the concrete does broadly slope towards the house, I'm wondering if this is almost just creating a 'moat' of sorts. So again, that plays into my concern about messing around with what the water is doing close to the foundations. As it is, the concrete can't be forming a perfect seal - there are cracks in it and water must get through to some degree. But much of it won't and will find its way into the drainage grate.
At the other extreme end of the scale, would it be better to just remove all the concrete and chuck a load of gravel on there? That way water should percolate down over a broad area rather than only in an exposed channel by the house. I would love to get rid of the concrete for many reasons, but the budget is tight so going for an aesthetically pleasing patio isn't top of the agenda.
And I haven't even considered ACO drains!
The whole garden is, sadly, covered in concrete which slopes towards the house. I think someone has tried to aim it towards the drainage grate but hasn't been completely successful. Ground levels are just below the airbricks under the kitchen floor, but because there is a step down to the utility room then the outside levels aren't all that different to the floor levels in the utility room. In the very heavy rain last week you could see water ponding against the house.
I had a quote for a french drain a few years ago, but I was nervous because my understanding is that houses in this area often have very shallow foundations and I didn't want to start messing with how water was moving there. I've recently had a builder suggest that a simple and cheaper option, at least initially, would be to cut a channel in the concrete around the perimeter, remove 100mm of hardcore/soil - whatever is there I suppose - and replace with gravel. I was hoping to get people's views on this approach rather than using a formalised french drain.
My understanding is that a french drain actually takes the water into a perforated pipe, whereby potentially drying the soil immediately adjacent to the house. It should be installed x distance away from the foundations, but I don't know if that entirely mitigates that risk. In this proposal, more water would surely drain downwards, but it would just percolate into the soil rather than being actively taken away.
They haven't specified the width of the channel that they propose. As the rest of the concrete does broadly slope towards the house, I'm wondering if this is almost just creating a 'moat' of sorts. So again, that plays into my concern about messing around with what the water is doing close to the foundations. As it is, the concrete can't be forming a perfect seal - there are cracks in it and water must get through to some degree. But much of it won't and will find its way into the drainage grate.
At the other extreme end of the scale, would it be better to just remove all the concrete and chuck a load of gravel on there? That way water should percolate down over a broad area rather than only in an exposed channel by the house. I would love to get rid of the concrete for many reasons, but the budget is tight so going for an aesthetically pleasing patio isn't top of the agenda.
And I haven't even considered ACO drains!