Water coming in to house from underneath the patio doors

ParkRobert

Hi all, we were recently getting new flooring fitted in our downstairs and when the company started taking off skirting boards they were rotting and soaking wet. We think there is water coming in the back patio doors.

We have had a glazer out to look at the door and check for leaks etc but he is unsure if the work he can do will fix the problem and that it could actually be when the previous owners landscaped the garden- new patio they may have removed the damp proof course or it’s not been properly fit for purpose so water is coming in somewhere.

It’s obviously been there for a significant time considering the skirting board is rotten. Not sure if the really bad weather has also highlighted it more. Is there anything that anyone can suggest we can do and do the previous owners/ company that carried out the work have any responsibility?

I have been told by a friend that it could be water running in from the stones and that building regulations states that the damp proof course should be a minimum 150mm above the slabs or stones. With and without the stones in place it does not meet the required 150mm. We have not made any changes to the garden or layout (including the stones around the side of the building).

In terms of difference between the slabs and the damp course. The damp course is only 0.5mm above the level of the slabs.

We bought the house about 4 months ago.

I have attached some photos.

Any help/information would greatly be appreciated.

Regards,

Robert


Robert

JGB1955

Looks like the patio needs to be lowered and (maybe) a French Drain installed.  There seems to be some mesh behind the stones/beneath the door.... wonder what that is supposed to achieve? 

And as for the previous owners being responsible - not a chance - caveat emptor.

FreeBear

ParkRobert said: I have been told by a friend that it could be water running in from the stones and that building regulations states that the damp proof course should be a minimum 150mm above the slabs or stones. With and without the stones in place it does not meet the required 150mm.

Current building regulations state a minimum of 150mm below the DPC - Not always achievable, so you should aim for a minimum of 75mm. Without digging up the entire area and reducing the ground level, your only option is to either install a linear drain between the wall & slabs. Alternatively, a french drain - Basically, a gravel filled trench ~200mm wide, 50-100mm deep, and ~75mm below the DPC.

Personally, I'd go for the french drain as it is easier to install and will cut back on the amount of rain bouncing up & soaking the wall. Long term, you should be budgeting to replace the slabbed area with one at a lower height.

stuart45

Ground levels can be at higher levels nowadays for wheelchair access, but the details need to be right. Here is an example, although it's for a solid floor.

plumb1_2

JGB1955 said:

  There seems to be some mesh behind the stones/beneath the door.... wonder what that is supposed to achieve? 

That looks like a piece of dpc that someone has put there to try to stop water ingress. So they’re known about the issue before.
Best way is to cut back the slabs and fit a channel drain

twopenny

Now I thought the mesh was raised with the pebbles on top.
That could mean there's a channel under where water is collecting and stayin as it can't evaporate.

It is a problem I've seen under the sills of patio doors before. The water runs off them and collects under where it is shady.
You need to get those pebbles up and see what is going on.
I found the mortar between the bricks was sodden and some rotted out. It was a miserable job digging out the gravel deep enough to clean out the mortar and let the whole lot dry out before repairing.

I've now leant some board or strips of slab against the wall under the sill. That keeps it dry and no further trouble.

stuart45

The mesh could be a.plastic DPC, as some have that shape on them to help grip the mortar.

ParkRobert

JGB1955 said:

Looks like the patio needs to be lowered and (maybe) a French Drain installed.  There seems to be some mesh behind the stones/beneath the door.... wonder what that is supposed to achieve? 

And as for the previous owners being responsible - not a chance - caveat emptor.

Thanks for you advice and opinion. It is damp course that you are seeing. We may try the French Drain option for now and then lower the patio at some point in the near future. Hopefully, that sorts it so we can have our new flooring installed.

ParkRobert

stuart45 said:

The mesh could be a.plastic DPC, as some have that shape on them to help grip the mortar.

Hi, yes the mesh is actually DPC.

ParkRobert

stuart45 said:

Ground levels can be at higher levels nowadays for wheelchair access, but the details need to be right. Here is an example, although it's for a solid floor.

Thanks very much.

greenface2

underneath the slider could be letting in water . Investigate and you may need to remove and make sure its properly sealed