How to fix drainage issue causing damp wall?

Hi guys,

I was hoping some for advice on how we can rectify this issue or who we should contact to help us sort this issue out. Renovating an old house and we’ve inherited quite a bit of rubbish like old sheds and building materials outside. We were about to put a PAX wardrobe in today and found the floor was leaking some water underneath from the rain. On the other side it looks like this (picture attached). The gutters don’t seem to be leaking (from what we can tell) but I’m assuming the issue is that we have this weird cutout in the concrete right up against the house that is catching all the water.

A few questions:

1. Would filling it in with more concrete and redoing the drain higher up work?

2. if so, should we slope the concrete away from the house?
3. In the meantime (while we remove the shed and things against the wall to get access) is there anything we can do seal it the wall so it stops letting in water?
4. Can we do this project ourselves or should we call in a professional and is so who?

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Comments

JacobZ

Hi @marthaishka,

It's a bit of a complicated issue to deal with because the concrete slabs supporting the shed and rainwater tank are in a way funnelling water towards the house. This is not ideal, and I would be inclined to remove these concrete slabs if at all possible.

Is it possible to get some wider shots of the area to get a broader perspective?

Ultimately, we need to limit the amount of water that can get near the walls and more specifically, where the brick meets the concrete foundation.

Is this section I've highlighted below the foundation of the house?

If not, is there a location that shows where the bricks meet the concrete that they sit on?

I would suggest having a drainage channel installed against the wall that sits below the level of the foundation. This would mean cutting a channel into the concrete so the top of the drain can sit below the level of the foundation. This drainage channel should then be plumbed to your stormwater outlet by a licenced plumber.

While this drain is being installed, you'll want to apply Bastion 4L Exterior Waterproof Membrane over the join between the bottom course of bricks and the foundation. This will create a barrier to prevent water seeping through this crack which is the likely location of ingress.

Unfortunately, this job is best left to the professionals. I would suggest contacting a plumber who has the capacity to cut concrete. You will want to have the channel cut, and then apply the membrane to the length of the wall before installing the drainage channel.

This is the best plan I can see from the information provided, but a plumber may be able to assess things better in person and offer a solution. I'd suggest contacting a plumber and mentioning what I've suggested above. They will be able to assess this plan and offer their recommendations.

Let me know what you think and if you have further questions, please don't hesitate to ask.

Also, allow me to tag @Dave-1 and @Nailbag for their thoughts.

Jacob

Dave-1

Good Afternoon @marthaishka

That area with the downpipe dosnt look like it drys out completely, ever. It has the green moss type deal growing on it so that means shade and no air flow. Also that the down pipe is possibly full from that bend onwards as the green sits at the join. Do you know if that pipe is clear all the way through?

The gully that is between the house and the slab looks like it also has water sitting in it long term as that black line looks like a tide mark.

Having the area free of debris (leaves, sticks) will help but I like @JacobZ 's suggestion about a grill drain. Im not sure if the concrete trhat the down pipe is sitting on is something that has been added to help maintain the are (but failed) or part of either slab. Do you know if there is a fall to that concrete? As in the base of the downpipe and away to wherever the pipe goes to? If there is no fall to that concrete it would certainly help pool the water.

Dave

Nailbag

Hi @marthaishka

Appreciating you want to do as much of the rectification yourself, I would make a start by removing everything out of the area that doesn't need to be there to give yourselves and any trades required an uncluttered open space to evaluate the situation. So thats the shed, old bricks, garden debris and any other rubbish.

With all that gone, the next step is to establish why water is being retained in that area so that can be stopped before repairing the damaged caused. For example, does the water tank have any sign that it leaks? What about its overflow drainage, is this plumbed to the stormwater and does it leak?

Can that stormwater pipe thats running through the channel be removed and redirected higher up across the wall and then down so it's not sitting within the channel? Both this and any other storm water connecting from the tanks needs to be done by a licensed plumber.

With the channel cleared, you could then look at applying the waterproofing membrane @JacobZ talks about. Then install the drainage channel which would be then concreted in to fill the remaining space. The channel will need to be at the worst case at the same level as the top of the channel and have some fall to take the water away. Again at the other end a plumber will need to complete the connection to the stormwater.

Personally, I think if you do some of there grunt work in clearing the area, take @JacobZ advice and get a couple of plumbers in to evaluate and quote on the repair work. You have only just moved in and its very important that this type of work is done right and anything else thats plumbing, electrical and structural (builder) in my opinion is invested in before cosmetics. Especially with an old home. Without doubt, early intervention will save you in the long term.

Nailbag

marthaishka

https://www.workshop.bunnings.com.au/discussion/comment/47579#Comment_47579

Hi @Dave-1 thanks so much for your reply. I’ve seen it dry before but it definitely collected water. We’re going to start clearing it out today now that the rain has stopped and order a small shed we can place away from the walls of the house to pack the old shed contents into. Then we’ll offer that old shed up for free or FB marketplace. (Someone might want it)

From inspection it looks like absolutely no fall on the concrete in the gully I’m afraid. It’s just rough lumpy concrete in that gully and no visible /or very little fall in the drain that runs along it. We don’t know if it’s completely clear but water is definitely running through to the other side.

I’m not sure of the black line you are referring to - there is a black line that is the dampcourse from the house slab there too.

Dave-1

https://www.workshop.bunnings.com.au/discussion/comment/85854#Comment_85854

Good Afternoon @marthaishka

The black line I was refering to is the green/black line of mould/slime in the first photo. It kind of looks like a water tide mark.

Sounds like you are taking the right steps in prepping the area to get it sorted. Once you have access then you can see even by pouring some water (once its dry) and seeing where it flows.

Dave

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