Hopefully someone can advise on my 2 following questions as i'm a bit undecided at moment!
1)
My house has a number of damp problems primarily caused by a good part of it having the external ground level up to 600mm higher than internal - see pic:
I'm planning to excavate and around the external walls and build an open perimeter drain with dished channel to gullys etc. My question is how would the detailing of this go? See below picture:
I want to use as little concrete as possible as I will be mixing it onsite as i go and im currently looking at a couple of cubic metres as it is! At the moment i am proposing to cast the L section in situ and then bed the dished channel on top, is this the best idea and if so what mix should i use for bedding the channel to the concrete base?
Any better/ simpler/ cheaper thoughts on detailing this?
2) I am also planning to install below ground water drainage further away from the house to intercept water as outlined in articles on this site - see sketch:
My question here is as I need this to be 20m long, I'm trying to cut costs as pea shingle ore similar soon adds up over this volume and length!!
Keeping the channel 700mm deep but submerging it 300mm down - i assume this is okay? Stone for this still comes to something like £25 a tonne and needing 7/8 tonnes worth!
Alternatively the website mentions Fin Drains being cheaper and easier, does anyone have experience of these or where to buy for domestic market in the UK?
Sorry for the long post but any advice would be greatly appreciated!.
Thanks.