Best way to divert water from leaking walls?

[pvcpro73]

Just after some advice please.
We did some work for a customer on an old mid terrace property, the makeshift rear extension was leaking from the roof so we built a new front wall and put a new pitched roof over, sorted no more water coming in from the roof but the floor is still soaking wet.
We discovered the old walls that the old guy built 30 years ago are leaking at the bottom but I don't know the best way to get rid of it without it costing him a load of money.
It's an awkward situation as it's his son's house but his son is in hospital and the hospital want to send him home, social worker said he can't go home yet as it's not fit for living, (the extension is used as a kitchen)
The old guy has already paid for the new roof and wall including new pvc window and door out of his own pocket and has said he hasn't got much more money left.
He wants me to fit some sort of drain at the bottom of the walls to channel the water out through the bottom of the new front wall then fit a timber floor above with a laminate finish, I'm not sure if that will work and don't really want to waste his last few quid on a bodge job that will only last until next winter.
I'm thinking it needs some sort of tanking type work but that will surely cost loads?
Sorry for the long post and I'm sure I've missed loads of info but please ask and I'll try to explain more if I can.

 

[stuart45]

What's the construction of the old walls that leak?

 

[pvcpro73]

They are single skin block walls but they are built just inside stone walls, one of which is a sort of garden party wall and the other is basically a retaining mountain wall!
Because he built these walls a few inches in from the existing walls he formed a cavity which is now bridged by all sorts of stuff including soil, branches, roots etc.
Also there is no access to the other side of the walls so any resolve would need to be internal!

 

[stuart45]

You might have to put in a French drain.

 

[pvcpro73]

Wouldn't that require access to the exterior of the wall?

 

[stuart45]

Only to take the water out to a drain.

 

[pvcpro73]

There isn't access to the exterior of the walls!

 

[stuart45]

Where's the nearest drain to get the water to?

 

[pvcpro73]

Just outside the new front wall

 

[stuart45]

Can you get the drainage pipe to the front from the kitchen.

 

[pvcpro73]

Not sure what you mean sorry!
Where do I put the drain and what type of drain?

 

[stuart45]

Pipe runs along wall and out to front. Don't know the layout of the house, so can't say the route. Perforated pipe.

Untitled

• stuart45
• 3 Feb 2014
• 1

 

[pvcpro73]

So I can install that on the inside of the walls?
It's the back wall and the right side wall that are leaking so can I join the pipes at 90 degrees?
Any idea what size the pipe is as I'll need to get some sort if timber floor above?
Can I make my own using half round down pipe?