Water ingress through floor - what are my options?

[MartyJ]

A few months back after heavy rain I noticed a very small pool of water on lino floor of WC (effectively in outbuilding with own roof)

Fast forward to this week, lino and floor tiles underneath have mostly been removed and after very heavy rain there are significant damp patches on the floor.

The gutterring is clear which leads me to think the source of water ingress is one of two places
1) previous owner built patio that is higher than floor of WC i.e. water could be coming in via the walls?
2) guttering feeds a drainage pipe that disappears into the ground i.e. potential issue/blockage there

If it's 1), what can be done? It's an old structure with no DPC, would internal tanking do the trick?

 

[MartyJ]

Some say time shots externally. On another forum the recommendation externally was to cut a channel between patio and wall.

What measures should I take internally of any?

 

[Deleted member 292770]

you could create a channel between the slabs and the wall. That won’t stop moisture in the floor though if there’s no dpm. If it was me i’d create a channel outside and tank the whole floor and a metre up the walls .

 

[MartyJ]

you could create a channel between the slabs and the wall. That won’t stop moisture in the floor though if there’s no dpm. If it was me i’d create a channel outside and tank the whole floor and a metre up the walls .

I think this is the best way forward too, thanks