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How to stop water ingress under house through external brick wall?

approachmhn
Having an Impact

How to stop water ingress under house through external brick wall?

 The external wall is single brick, I am getting water coming through the brickwork to crawl space under house when it rains .

 

I can get to both positive and negative sides of the water transfer.

Is there a suitable product to seal the wall on the outside or inside.

the upper part of external wall is rendered. So I think water ingress is through bottom where wall is not rendered and is covered by soil.

appreciate your suggestions

thanks.

IMG_6296.jpeg

IMG_6080.jpeg

MitchellMc
Bunnings Team Member
Bunnings Team Member

Re: how to stop water ingress under house through external brick wall

Hi @approachmhn,

 

It sounds like you'll need a multifaceted approach to resolve this issue. The correct way to do this is to dig a 200mm wide trench along the from of the wall to the depth of the bottom of the brickwork. You then need to waterproof the bricks. Next, lay a socked slotted Draincoil in the bottom of the trench and connect it to your stormwater pipes. Note that you'll need a professional for the connection. You can then backfill the trench with drainage gravel

 

Although there are membranes that can withstand hydrostatic pressure, simply painting one on the inside of the wall is unlikely to resolve your issue, as the water will then try to migrate under the bricks. Installing a Draincoil, capturing the water and diverting it elsewhere will be the most likely solution.

 

Please let me know if you have any questions.

 

Mitchell

 

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Dave-1
Community Megastar

Re: how to stop water ingress under house through external brick wall

Morning @approachmhn 

I was just scrolling, scrolling and then BAM! Saw you pic, I would swear that it was the photo I took ages ago of under my house! lol Same issue, same description. The way I fixed it was to actually remove the concrete path (had to to replace my old stormwater pipes) and when i relayed the path with large pavers I used a gravel base underneath. This plus the stormwater pipes being covered in gravel has mean that I dont get a lot of surface water running up against the single layer brick wall and filtering through the brickwork/mortar to form mini waterfalls! Side path rebuild from recyled pavers 

 

Here are some photos of the leak and the path which was helping teh water seep under the house as the path fell back towrads the wall.

01 04-11-2020.jpg

02 04-11-2020.jpg

04 04-11-2020.jpg

05 04-11-2020.jpg

Removing the water chaneling towards the wall worked well. If you dug out the soil against your wall and installed drainage or left the soil at a lower level that could also solve your problem.

 

It really came down to removing the ability of the water to run that way more then seal the brick work. I have sealed the brickwork in another section of the house and it also worked nicely. Fixing water ingress issues in garage 

 

Dave

 

Re: how to stop water ingress under house through external brick wall

Thank you very much @MitchellMc  and @Dave-1 .

 

with all the suggestions you have provided, I just need to make sure implement it asap.

hope if rain gives sometime this week or next, I will do this over a weekend.

my storm water pipes are at the other end of the driveway. which means I need to cut concrete to connect.

As a first step, I will just leave the water to filter through gravel and flow across driveway.
If it is too much of water flowing across driveway, what is the best solution without cutting concrete?

EricL
Bunnings Team Member
Bunnings Team Member

Re: how to stop water ingress under house through external brick wall

Hello @approachmhn 

 

Would it be possible for you to post a photo of your driveway? This will give our members chance to assess its layout. We can then offer suggestions how to handle the waterflow without cutting into the concrete.

 

Eric

 

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Re: how to stop water ingress under house through external brick wall

Hi @EricL ,

thank you for your response.

Please find the photo of driveway attached. Driveway towards fence is slightly sloped like may be 3-4 cm.

storm water pipe goes next to fence under the soil. Renewed with pvc pipes. We had to remove all scrubs and small trees next to fence because old clay pipe under was damaged due to roots.

IMG_6394.jpeg

 

Re: how to stop water ingress under house through external brick wall

Evening @approachmhn 

Oh man, I know about replacing those old pipes :smile: wooooo lots of effort involved.

 

As to cutting the concrete, I can see a join line across the driveway. Id use the low side as an edge and cut the high side of it in a straight line across the driveway. I was lucky as my carpenter mate who was use to using a concrete cutting blade/saw did it for me (he also had the saw :smile: ) I paid him even tho he said nah. By chance, he says on purpose (did not see him measure the distance or the pavers lol ) he cut a beautiful line the perfect distance for pavers to be laid across the width. If you are unsure Id actually hit up a builder to do it as you want it to look nice. When the pipe is laid you can either fill to a little overthe pipe with gravel and reconcrete or pave as I did (if you are going to pave you will need to make sure you have enough support aroundthe pipe for a car to sit on the pavers)

 

Dave

Re: how to stop water ingress under house through external brick wall

Hi @approachmhn,

 

I'm unsure how you'll allow the water to flow across the driveway. To install the drain coil and drainage gravel, you'll need to dig down to the bottom of the wall. Your drain coil will then be much lower than the level of the driveway, so I can't see the water flowing across it.

 

Drainage plumbers will have access to machine that can't dig a hole and run the pipe under the driveway without cutting through it.

 

Mitchell

 

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Re: how to stop water ingress under house through external brick wall

@MitchellMc  I understand now.

 

can I put a concrete slab next to the wall. May be a metre width.

will that stop water ingress through brick?

Re: how to stop water ingress under house through external brick wall

If the water comes only from the surface, that might work @approachmhn. However, the moisture is likely also coming from beneath the soil and a concrete slab on the surface likely wouldn't resolve that issue. It could help, though.

 

Mitchell

 

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