Water ingress from outside into timbers, brick veneer house - cementitious membrane

[simopimo]

Hey there waterproofing people

My house, brick veneer, built 7 years ago, is on a concrete slab. The concrete paths which surround most of the house are at the same level or slightly higher than the house slab.

2 years ago my tenant warned me of this as there was mould on the floor in some parts and the laminated floor boards near a particular corner were showing signs of rotting. I pursued the builder under home warranty provisions. He made some sort of effort and hired a waterproofer to apply a sealant between the concrete path and the brickwork and replaced most, but not all, of the damaged baseplates/studs. Also replaced the floorboards which we paid 50/50. I've been to NCAT 3 times and the builder is just dragging this on as long as he can. I've since moved into the house and decided to fix this up properly.

Some of the (non-replaced) base plate studs still show signs dampness after heavy rain. I initially wanted to install strip drains around the house. The concrete paths around the house are all perfectly level which is part of the issue - there's no fall. A (different) waterproofer and a builder doing some other work for me both recommended that I apply a cementitious membrane to the bottom 3 courses of brickwork all around the house. They said it should fix it without needing strip drains, and to at least try that first anyway before going to the hassle of a strip drain.

I ended up being recommended Duroflex TANK by the local waterproofing shop, so I bought that. However I believe I'll also need bond breaker tape for the wall-to-ground junction.

Questions:

• Do I need bond breaker tape? If so, would I require a specific type? I believe there aren't compability issues between different types of membranes and bond breakers, but checking to be sure.
• I'm pretty handy, but haven't done this before. Both my builder and the waterproofer (who was epoxy-coating my garage, but used to be a waterproofer) said just slap it on, whether I use Gripset C1P/C2P, Crystoflex or Duroflex Tank - doesn't matter, just get it on the surface. Does this sound right?

Main concern I had was regarding bond breaker as I'd like to do this right. I was just going to get a 50m roll of Bastion bond breaker from the Big Green Shed as it's easy to get hold of.

Advice appreciated!

[droog]

Not familiar with the product itself but with any product you should always follow the manufacturers recomendations
https://www.durotechindustries.com.a...roflextank.pdf

For movement joints Durotech Elastic DetailingTape is to be applied over joints followed by the
application of Duroflex tank. For non-movement
cracks, these are to be filled first with Duroflex
tank and reinforced using durotech reinforcing
tape prior to over coating with membrane. For
waterproofing applications on the positive sides,
wall/ floor junctions are to be protected with the
Durote chBond breaker Detailing Tape
embedded into the coat of Duroflex tank. For
negative applications a waterproof fillet is
recommended to be used at junctions using Duro
additive or duroflex Plug

Both my builder and the waterproofer (who was epoxy-coating my garage, but used to be a waterproofer) said just slap it on, whether I use Gripset C1P/C2P, Crystoflex or Duroflex Tank - doesn't matter, just get it on the surface.

Unless they are providing the warranty and support for application via this method I would default to the manufacturers recommendations and advice.


The correct construction should have the brick veneer stepped down at the edge of the slab and a vapour barrier under the brick, the bottom plate should not get wet unless this is breached.
Do you know how it was constructed and is it incorrect construction or is the barrier breached ?

Any applied membrane over the brick and path is going to look like a band-aid and is prone to future damage.
I would look at removing the path and digging down the surrounding area so there is no ability for the damp to get to the brick, if there are still issues I would look at Silicon damp proof injection int the bottom row of bricks.

[simopimo]

Thanks for your help droog.

The issue is that the concrete path at 2 sides of the house, is higher than the floor. The brick veneer is stepped down at the edge of the slab, I've had a report done by NSW Master Building inspections and I've measured the moisture levels. The idiot who poured the paths did not put a fall into the path so it doesn't channel away from the house. It's just a standard brick veneer construction, and was certified so it was done to code, whatever that was in 2017. The height of the path is the issue. I am not the original owner of the house but it was all certified (for what that's worth).

Removing part or all of the path and installing a strip drain next to the brick wall is something I will do if the waterproofing is unsuccessful, but isn't something I'm willing to tackle right now for a range of reasons, especially with the largest part of the wall requiring access to the neighbouring property.

After replacing the damaged baseplates 2 years ago and a silicone/mastic/rubber fillet was injected between path and brick work, the moisture has mostly gone away but there's still a detectable level of moisture in some of the timbers after heavy rain - probably 10% of the timbers. I noticed this because the first thing I did when I got my house back was to cut the bottom of the plasterboard off to inspect.

I spoke to the retailer who I bought the Duroflex Tank from today. He recommended a bead of Duroflex 50FC sealant all along the wall, allow it to cure and then the Duroflex Tank over the top. I asked him about bond breaker cloth and he said that the tradies he is supplying are getting good results using that combination.

Not familiar with the product itself but with any product you should always follow the manufacturers recomendations
https://www.durotechindustries.com.a...roflextank.pdf




Unless they are providing the warranty and support for application via this method I would default to the manufacturers recommendations and advice.


The correct construction should have the brick veneer stepped down at the edge of the slab and a vapour barrier under the brick, the bottom plate should not get wet unless this is breached.
Do you know how it was constructed and is it incorrect construction or is the barrier breached ?

Any applied membrane over the brick and path is going to look like a band-aid and is prone to future damage.
I would look at removing the path and digging down the surrounding area so there is no ability for the damp to get to the brick, if there are still issues I would look at Silicon damp proof injection int the bottom row of bricks.

[mic-d]

I'm with Droog, waterproof membranes fail eventually, and how do use get access to where the wpm needs to be. I'd bite the bullet and dig up the paths that are too high and correct it as Droog suggests

[droog]

Given the extra info, I am even more convinced, get rid of the path and lower the level around the outside.
Short term pain for long term gain. No concrete path does not stop access, it might make it messy or more difficult but do you want to solve the problem ?

[simopimo]

Thanks for the advice guys.

Based on your advice, I'll dig the concrete out later this year. I need to get the OK from the neighbour first as it also joins to their slab. I have access rights/easement to my back wall up to 900mm, but I need to run it by the neighbours etc first, so I'll put that on the medium term list. Here's a pic - my house on the right, neighbour's on the left. Path is level. Builder's waterproofer put in a rubber seal between footpath and brickwork. It's helped, but hasn't totally solved the issue.

As mentioned above - I can't dig up the whole path without getting the neighbours onto it as well as it would impact them also, so perhaps I will cut the concrete along my wall out to about 20cm or so, and put in a strip drain instead.

For my northern wall, which is entirely on my property, I could dig up the whole lot in the medium term as you've suggested.

Eastern Wall below - mine on right, neighbours on left. Flat path - no fall - perfectly flat. Stupid concreting!!!

20250504_151809.jpg

Northern Wall - entirely on my property - also perfectly flat path - no fall away from house. This one I can dig out, and was where most of the moisture was entering from. I have no problem with the aesthetics of a waterproof cementitious coating on the lower few courses here for the short term as it's not visible. And then medium term, dig it all up, new path angling away from the house and lower.

20250528_123846.jpg

[droog]

OK pictures help a lot.
I would cut out a section where the worst problems are, dig down and find out where the bricks are sitting on the slab.
There should be a dampcourse layer close to the bottom, usually it is a different colour mortar or could even be plastic poking out of the mortar. If there is one then your outside surface level should be below this. If you cannot find one then try and get your strip drain close to the bottom of the bricks.

[havabeer69]

i'd waterproof against the bricks and part of the slab and slap some hydraulic cement over it at and angle so any water is diverted to the middle of the path and hopefully to a drain

[ErrolFlynn]

Lower the footpath and make it drain.

I had a similar problem (in a house I used to have). It took a lot to fix. I had only been in the house for about a month or so. A heavy rain shower saw the gutters overflow. Water was coming into the house. In my case the water level was about three inches above the path, and with the floor-to-ceiling windows, the view from inside was like looking into a partially filled aquarium.

When the rain stopped, I dug up the path, crappy as it was, but that helped. The rock underneath could hardly be budged using a crowbar. I had to rent a compressor and jackhammer, and I don't know how many weekends I spent removing rock before I could replace the footpath at a lower level.

You may need to do the same.