How do I fix damp issues caused by outdoor pathway/staircase?

[pippajennings]

Hello,

I’m looking for guidance on how to fix the damp issue on my newly purchased house.

The damp is on a lower level living room and is on the inside of the single brick wall  that runs alongside a poorly constructed cement staircase pathway. On the inside, the damp is at a right angle to a stud wall which separates the living space from an underground storage room. More info below. 

We understand that the damp has been caused by the following key issues:

(1) an external staircase which runs alongside the external brick which is angled towards the house and not away, so heavy rainfall is going towards the house instead of away from it;

(2) a small gap which has opened up between the external stairs/pathway and exterior wall where heavy rainfall is getting in; and

(3) poor drainage and subfloor ventilation in an under house storage room (which is essentially a vacant space with exposed earth / rock) which runs parallel to the staircase.

I would really appreciate advice on what the best solution is to fix this problem and who to engage to help. 

We have spoke with three specialists who have provided conflicting advice, being:  

- One damp specialist quoted $9k (not including gyprock/soil removal or stud wall modifications that need to be done by a carpenter). Their solution was to waterproof / damp cream inject the brick wall with mould, and add hebel under the stud wall and add waterproofing to that. They said we could leave the outdoor pathway/staircase as is, and that it wouldn’t matter if water got in through the pathway crack as it wouldn’t get through the internal wall waterproofing.

- A second damp specialist quoted $3.4K to replace poor quality vents in under house area to increase ventilation under the house. He said a better levelled pathway would also need to be done, and suggested gravel/pavers as a good option (services not offered from him though). 
- A concrete specialist whose quote came back at $10k. They proposed leaving the internal mouldy wall and that it would sort itself out in time, and to demo then relay the concrete pathway/staircase properly.

We would like the solution to fix the damp, improve the aesthetics of this pathway and it be a cost effective solution. We are very happy to engage professionals for certain jobs, while doing other aspects ourselves to keep costs down. 

We have researched some alternative pathway materials and are very open to gravel/pavers, tiling, etc. as an alternative to concrete. 

We would really appreciate your advice and suggestions on how best to sort this problem out! Thank you very much in advance. 

 

  

[EricL]

Hello @pippajennings 

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

I propose engaging the services of a tradesperson to jack hammer the surface of the concrete path and steps to remove the fall going to your house. Once the surface fall has been removed, I suggest resurfacing the concrete path and steps with the fall going away from the house. This single correction will immediately remove a large amount of rainwater being directed to your house wall. I also suggest filling in the gap between the path and your wall with Sika 310ml Grey Concrete Sikaflex Pro+ Polyurethane Sealant.

Next, I recommend addressing the drainage and subfloor ventilation. Would it be possible for you to post a photo of this area. This will give our members a better idea of what it looks like. Putting in proper drainage is essential as it carries away standing water and moisture, if left to drain on its own water will find the lowest point possible with the least amount of resistance which I suspect is the bottom of your brick wall. The suggestion of improving ventilation is also an excellent idea as it moves the trapped moisture in the area preventing mould and mildew from developing. 

Let me call on our experienced members @Dave-1, @Jewelleryrescue, @TedBear and @JoeAzza for their recommendations.  

If you have any other questions we can help with, please let us know.

Eric

[Dave-1]

Good Morning @pippajennings 

As soon as I saw the path and the inside wall of the room I had flashbacks of mine Below are a few links of the fixes that I had to do to stop the surface water as well as the subsurface water to a large degree.

The first link shows the water coming in from the highside of soil next to the garage wall. This was a larg job but the only way I could really stop any moisture from traveling through the brick into the garage. This has worked extremely well.

Fixing water ingress issues in garage 

The second shows how I redid the path with a gravel surface and pavers. This has worked amazingly well with no more instances of water under the house. No channeling within the gravel either.

Side path rebuild from recyled pavers 

The third link shows the water coming in from the edge of the concrete (not so likely) but more subsurface wise. As in traveling underneath the concrete withing the soil.

Stormwater rectification stage 1 

In relation to your path and steps. I agree with @EricL 's solution. 😕 Its a large chunk of work but the water needs to be stopped if you want the issues undre the house to stop. I would redo your path and have it slope away plus drainage to take all that excess water elsewhere down your yard. I cnat see any ventilation vents in the brickwork in you photos but have a look and see if you can find them. If soil has covered them then that needs to be sorted as well. 

It is a big job but doable, have a think of what you could have if you rip up the path I have come up with loads better areas for my place by thinking that way.

One note of caution, when removing the concrete you need to support your fence posts in case it wealens them.

Also If you cut a channel down the side of the path about 200mm from the house and put in a grill drain and sealed it... Id say its a easy way to quick fix but dont think it will solve your problem long term. (May let even more water in)

Dave

[Jason]

I can sympathise @pippajennings. It is challenging when you get different advice from professionals.

Let me also tag experienced renovator @Nailbag to see if he can join the discussion and share his opinion. 

Jason

[pippajennings]

Hi Eric, 

Thanks very much for the warm welcome and speedy response! 

The concrete pathway/staircase is of pretty poor quality and has significant chunks that have fallen out along the steps (I don't think any steel/structural elements were used in the original DIY job unfortunately!). In addition to this, we recently noticed the concrete platform at the base of this pathway (see photo with wooden staircase leading off it, no photo of gap itself sorry) has a 3-4 inch gap between the concrete and earth. With this being the case, would you still suggest jackhammering and resurfacing as the best solution or do we need to start it from scratch? 

Sure, I've attached two photos below of the lower ground under house storage area (taken when we inspected the house, has a lot of the previous owner's stuff in there so not the clearest view sorry) where you can see a couple of vents that are quite old and not up to current standards. The flooring under there is open rock/earth with bricks placed on top, but there's no sub-floor or drainage system in place for any water getting into that room to divert it back out of the house. 

Bottom of concrete pathway/staircase Under house storage area (with small vents, not up to standard) Other side of under house storage area

[EricL]

Hello @pippajennings 

Now we come to the decision-making part of your repair. I propose studying the area very carefully and picturing in your mind where the water will flow should you decide to do a major overhaul of the area. I propose engaging the services of a plumber so that they can provide insight on the best way to divert the rainwater coming into your area.

If the pathway/staircase are not that robust then it would be wise to remove the old one and start fresh. With the new pathway/staircase, I suggest installing Everhard 3m EasyDRAIN Polymer Grate And Prejoined Channel on the side to catch any rainwater that falls on the path/staircase. Your path/staircase acts like a funnel, any rainwater that falls on it does not get absorbed but redirected and it's important that this redirected water be sent towards your stormwater drain. 

If you have the budget for it, I recommend digging underneath the house to remove that fall that is directed to your wall. I recommend putting in a properly sealed concrete base along with a sealed wall. You can also install a drain at the bottom of that base should any water happen to come through that area. As Dave said it is a large chunk of work, but if you address these issues now, your house wall and foundation should be protected from any future rainstorms that may come your way.

If you need further assistance, please let us know.

Eric

[Dave-1]

Good Afternoon @pippajennings 

Thank you for the extra photos. I was hoping to see some air vents below the damp proof layer of your brickwork. The stuff that is stored kinda blocks all that area 😕 You should be able to see them outside but I have a sneaking susppision that may be burried. If you look at most brick houses you will see little little vertical slits just bellow floor level and the bricks may "jut" out a tiny bit (by 1cm)

The photo showing the end of the path kind of suggests that the whole area under the concrete may have been filled with rocks/bricks and then concreted over. This could explain how water would get under the slab and then make its way through to the room underneath via the brick wall. Having cavitys in the soil from builders refuse covered over was the reaon I had the water enter my garage. 

What is under that old lino under the steps and is it wet? If there is water trickling it shows there is a path down the hill the water is following.

Dave

[Nailbag]

Hi @pippajennings 

Anything internal sub level to external ground level is always a major challenge in maintaining essentially a waterproof barrier. You have done an admiral job of detailing the points of concerns and engaging the 3 quotes. Unfortunately each offers are completely different approach and price point in rectifying the issues. This is further complicated as none offer a turn key solution as they require the services of other trades they aren't offering to project manage.

The external concrete stepped pathway is not much thicker in depth to what you see, with each tread I would guess no thicker than about 150mm. This means what lies beneath is soil of some type. Water is penetrating through the gap where the stairs meet the brick wall and soak through under them. Dampness will be making its way in the sub-floor area throughout the plasterboard thats exposed to that area. Even with an increase in ventilation you're always going to be dealing with a deep underground internal space.

My advice would be to contact a local domestic engineering company to evaluate the scenario and provide direction as to what works are required. Then based on that information they could advise what trades/services you would need to complete the works. It will require multiple trades-people to be project managed as required. Project managers are also a service you can engage.

Apologies I can't offer more definitive advice, but its what I would be doing.

Please keep us in the loop.

Nailbag

[pippajennings]

Hi Dave, 

Wow I can definitely see the similarities! Thanks for sharing those links with me, very helpful in understanding what we need to be ensuring is in place and working under the surface of whatever style we go for.

I read gravel/pavers was a really good option for dispersing water flow, so it's good to know it's worked really well for you too as that is what we're leaning towards (photo attached of what we'll be aiming for - potentially without stairs if the slope isn't too steep). 

We will take out the fence posts while we're at it removing the concrete, thank you for the caution though!

Thanks, 
Pippa

Side pathway/staircase vision/inspo example

[pippajennings]

Hi Eric, 

Thank you for your sound advice. Based on everyone's great feedback, we think our plan is to:

1) Engage a plumber this week to discuss: 

(a) Establishing proper drainage in the internal storage space which is currently exposed earth and quite damp, especially during periods of heavy rain (we will also discuss improving ventilation in this space (noting we may need other specialist for this TBC));

(b) Establishing good stormwater drainage on/underneath new pathway/staircase down side of house; 

2) Subject to the plan agreed with our plumber for dealing with stormwater drainage, we will engage an excavator to remove the current concrete pathway/staircase and handrail.

3) Install waterproofing along exterior brick to seal the brick.

4) Relay new pathway / staircase (leaning towards a gravel/paver solution), which may include amending the positioning/quantity of steps.

Hopefully this plan sounds sensible, please let us know if there's anything you think we have missed or is unnecessary. 

On the Everhard grate at the bottom of the hill/pathway/staircase, we will bring this up with the plumber. Thank you for this suggestion!

Thanks

Pippa