What could be the source of moisture on external bricks?

[bluewave1]

Good evening all,

Was hoping to see if anyone has had similar experience with the question above.

Bit of background - we’ve recently noticed that the bricks on our driveway have started to become moist. It’s pretty much on both sides of our front foyer (our entry way is elevated with a few steps). It also appears to become larger and larger. Photo attached for reference.

Approximately six months ago, we did a DIY wood sleeper retaining wall (5mx400cm, on the other side) as our block is slightly sloping. We made sure that the weep holes remain exposed and sit above the soil line. 

We are concerned and hoping that it is not too serious as we’ve just moved in. In the meantime, we are trying to organise a building/leak inspector to see where the moisture is coming from. Also looking to get a proper landscaper redo our DIY and possibly put a drain when the retaining wall is rebuilt.

I suppose before we go through all the above options (anticipating huge costs involved), we wanted to see if this is something that we can fix.

Thank you all and hoping for some help/advice.

 

[EricL]

Hello @bluewave1 

Welcome to the Bunnings Workshop community. It's sensational to have you join us, and thanks for sharing your question about moisture coming from your brick wall.

I was going to suggest engaging the services of a leak detection specialist, but you've gotten ahead of me. They should be able to track down where the water is coming from. My thoughts are if the other side of that wall is hollow and there is no soil or plumbing in that area, it's possible that water is travelling inside that wall and is pooling specifically in that area. Where that water is coming from is the big question.  

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

If you need further assistance, please let us know.

Eric

[bluewave1]

Thank you @EricL for your response, much appreciated.

[Nailbag]

Hi @bluewave1 

Unfortunately there maybe rainwater leaking internally which can be serious is left. Quick fixes like making sure the gutters and downpipes are clean. Roof tiles in place and in good condition. Failing that, you can either get a roof plumber if you have a colourbond roof in to check or as @EricL suggested a leak detection service to establish the cause and advise who and what needs to be done.

Nailbag

[Dave-1]

Good Morning @bluewave1 

Would it be possible to get a few more photos from the front on and also of the 5m garden bed? Its hard tto see the discoloration you mention from the photo. The driveway does block the weepholes/air vents as it slopes and by the height of the vents we can see the garden bed would be covering the holes from teh front. I cant see the other side of teh steps but am presuming that the garden beds would be roughly the same height?

If you have changed where the water would normally run (that retaining wall) and soak in, water will find the next easiest path to travel downhill. I would backtrack from where your dampness is and work my way up the slope thinking of the garden bed as the main culprit atm.

Dave

[bluewave1]

Thank you @Nailbag much appreciated

[bluewave1]

 

  

Hi @Dave-1,

The new retaining wall was my first suspicion, given the soil wasn’t touching the brick until we’ve DIY it. The end of the sleeper also started to lean outwards after a week of rain, hence we’ve just placed a metal pole to support it. Prior to the DIY, the soil was already sloping from the garden bed (near the window). Essentially we’ve backfilled it up to the column and then placed a retaining wall so it’s easier to mow. Unfortunately is also present under the powerpoint on the other side of the entry way.

I’ve added more photos from different angles if it helps. 

@Nailbag - we’re also thinking about the rainwater drain, we’re not sure if the underground rain water tank is actually under the house or under the garage. Hopefully it’s not too sinister as it sounds very costly if it involves the entire rainwater system

thank you all for your input.

[Dave-1]

Good morning @bluewave1 

Thank you for the photos, I think they show how the moisture is getting into the brickwork.

So a question, or a few questions.

- Did you line the brickwork you backfilled up against with anything?

- Did you install agi pipe or some other form of drainage behind the new retaining wall?

- Did you install any type of drainage around the edge of the house before backfilling?

Subsurface water is water you cant see that travels downslope undre the grass, its a resonable amount of water that shifts this way (Yeah I didnt know either) Putting drainage in to mitigate the issue would be my first step toards solving your issue.

- Remove soil from brickwork edge of house by 300mm from the wall.

- Remove soil from behind the retaining wall by 300mm from the wall.

- Soil is removed to base of retaing wall, same depth as against the wall.

- 30mm fine 8mm gravel first.

- 100mm socked agi pipe run aroundthe whole edge of the area.

- Backfilled with gravel to 20mm above the pipe

- Weedmat then Soil and grass on top.

- Agi pipe exit needs to drain freely to somewhere, stormwater or a low point. 

- The brick work should also be sealed with some bitumen styled paint to just below the grass level. Note that that stuff is sticky and smells for a little.

I still cant see the dampness you first described tho, its not directly underneath that patio area?

Dave

[bluewave1]

Thank you so much Dave, this is very helpful. Unfortunately my answer is no for all the questions you had - this tells me that we would need to get the retaining wall re-done and have appropriate drainage and other prep work undertaken.

The initial dampness is on the first photo (driveway side), it’s directly underneath the patio area. I think you’re spot on with the water flowing through given there is no drainage on the other side. At this stage we are not sure what is under the patio (i.e. filled with soil or void)

From here I think we will proceed with the landscape remediation first, then if still ongoing we’ll follow through with the leak inspector.

thank you all for your help @Dave-1 @Nailbag @EricL 

[Dave-1]

Afternoon @bluewave1 

If its just under the slab for the patio floor, then it looks like general water runoff from your patio. I wouldnt be overly concerned and would keep an eye for pooled water on top against the house. A stiff brushing would clean the dirt that tracks onto the brick from the corner.

Dave