How to fix a drainage issue at the back of two storey terrace house?

[justaussie]

Hi there, so - I have a drainage issue at the back of the house.  My late parents bought the house about 42 years ago and until 2 years ago we didn't have an issue.  Then the floor boards got rotten from water damage.  The back of the house and the brick backyard are against one another and it seems that water had seeped under the floor of the house and damaged a joist and the floor boards.  I have builders doing fixes on the house - and they were going to lower the bricks but discovered they cannot due to the height of the drain running along the side of the property out to the alleyway.  They said they could drop the bricks a short way, then raise them but terrible tripping hazard, then said could waterproof them and put that black rubber water proof material around the back and corner of the house and would last awhile - but it would look terrible.  I read about a French drain and wondered if that might be an option or if you can suggest anything else.  The house from the back door to the side drain has a slight slope to the drain but obviously not good enough to stop water from getting under the house.  I've attached some photos of the back door to the bricks then the side corner and the drain at the side of the property that goes along the edge to the alley behind the property where it drains out.  they cleared out the drain and tested that it worked along the side of the property. Thank you for your advice - I really don't like the proposed black rubber running along the back and corner.

[EricL]

Hello @justaussie 

Welcome to the Bunnings Workshop community. It's sensational to have you join us, and thanks for sharing your question about your drainage. 

For a long-term solution, I propose removing the brick pavers and digging around the sides of the house and applying the Gripset Betta 1L Waterproofing Membrane Bitumen Rubber on the lower sections of the wall of the house to prevent water from going in. This would also be a good time to fix the drainage in the area. I suggest engaging the services of a licensed plumber to add a drain channel such as the Everhard 3m EasyDRAIN Polymer Grate And Prejoined Channel and redirect the fall of the pathway. 

It is possible to install a socked agi pipe for added drainage, but this is best discussed with the plumber. Once the plumbing has been sorted out, I suggest re-laying the brick pavers but this time with no gaps. This will limit the amount of water water that will pass through, and it will all get redirected to the new drain channel that has been installed. I suggest using a traditional filler such as sand and cement so that it will not get washed away.

In order to waterproof the higher sections of the wall, I suggest using Crommelin 1L Exterior Grade Brushable Waterproofer - 1L, it's grey in colour and looks much better than the black bitumen paint.

Let me call on our experienced members @Dave-1 and @Nailbag for their recommendations.

If you need further assistance, please let us know.

Eric

[Nailbag]

Hi @justaussie 

I have to be straight up and say that This appears to be a situation that an online solution isn't going to provide a solution as there are a lot of variable and unseen complications.

At first glance, the concreted pavers are at ground level to the green door frame, which isn't good. the pavers should be well below the door sill level with a drainage system running around the perimeter. 

If you're not satisfied with the solution the builder has suggested, then get another 1-2 quotes to see what their solution is. Better still is get the advice from an engineer who will be unbiased in whats required so you can then enlist trades to perform the required works.

Nailbag

[Dave-1]

Good Morning @justaussie 

I actually like the paver setup you have but straight away I know that you will probarlly have to pull up all of it to fix the issue.

It will be a large job with a few things to factor in as @EricL and @Nailbag have both mentioned.

Seperation of the pavers to the house and waterproofing of the brick wall below ground level. (stop water coming into under the the house)

Change the fall of the pavers so it slopes away from the house.

Drainage to take the water away, the grilled drain that @EricL mentions is definently what I would be using all the way along the fence line.

Joining the drainage to stormwater (Would recommend a plumber for this and also to suggest other drainage solutuins)

Fixing the area from the back door out to the pavers with the grill drain as well.

All this you can do yourself  

Stormwater rectification stage 1 there is also a stage 2 and a whole bunch of flow on associated projects. It takes time and some work. I found it enjoyable tho every now and then it was "ugh"

Start off with a few more quotes as @Nailbag has mentioned. then determine what you want, what paving style and the projects will go from there. Hit us up for questions over something you may want as someone in the community will for sure have had the same question

If I had to grade the amount of work out of ten Id say an 8-9

Technical wise 4-5

Messed up yard  6-12months at least.

Dave

[justaussie]

Many thanks for all your advice - much appreciated.  I actually found out that the black rubber they proposed goes under the bricks not over - and I think what they are proposing will work - they'll be digging up the bricks and laying waterproofing etc.  Hopefully will all work out.  Many thanks for the information.  Cheers, Justine

[EricL]

Hi @justaussie 

Please keep us updated with your progress, we look forward to seeing the drainage problem sorted out.

If you need further assistance, please let us know.

Eric