the problem is water getting in down stairs.
Welcome to the Bunnings Workshop community @johnblades. Is sensational to have you join us and many thanks for your question on moisture issues.
From what you’ve shown, it’s unlikely that driving rain is penetrating straight through the painted block wall itself. Painted blockwork generally does a decent job of shedding water.
A more likely weak point is higher up. One area to check closely is where the timber panelling upstairs meets the window ledge or frame. If that junction isn’t well sealed, wind-driven rain can get in there and track down inside the wall cavity. Making sure that joint is properly sealed will help ensure water just sheds off rather than getting in.
That said, if the issue is showing up downstairs, another very common cause is moisture entering at or below ground level and then working its way up through the wall. This is especially likely if there’s no effective damp course in the blockwork, or if it’s been bridged.
At this stage, the biggest unknown is how the water is presenting internally. For example:
If you can share a bit more detail on where and how the moisture is appearing inside, it’ll make it much easier to narrow down the cause and suggest a proper fix.
Please let me know if you have any questions.
Mitchell
It only happens in driving rain with strong NE or E windThe water drips from the internal frame of windows in photoThe walls are damp and there is no membrane it is cut into the bank so there is hydroscopic pressure
Hi @johnblades,
If water is dripping from the internal window frame, that strongly suggests it’s getting in from around or above the window externally, rather than straight through the block wall. From your photo, the junction between the timber cladding and the window frame doesn’t look particularly well sealed, which is exactly the kind of spot where wind-driven rain can be forced in. I’d start here by inspecting that joint closely and resealing it with https://www.bunnings.com.au/sika-310ml-white-sikaflex-pro-polyurethane-sealant-310ml-white_p0083587 to close up any gaps.
The second issue is more significant longer term. Since the wall is cut into a bank and not waterproofed, you’re likely dealing with hydrostatic pressure pushing moisture into the wall. In situations like this, a damp course alone isn’t enough. If the space downstairs is habitable, a proper waterproofing membrane is typically required to stop moisture entering the structure. The most effective solution is to address this from the outside by excavating the soil away from the wall, applying a waterproof membrane, and installing drainage (such as an ag pipe with gravel) so water is redirected away before it can build up against the wall.
There are internal coatings that resist hydrostatic pressure, but these tend to trap moisture within the wall, which can lead to further issues like moisture migrating higher up. It’s generally much better to stop the water before it gets in.
thank you Mitchell f
Mitchell I am in New Zealand and Bunnings do not have that product would Silaflex11FC Purform be similar
I mean Sikaflex 11FC Purform
Here's the https://www.bunnings.co.nz/sikaflex-11-fc-purform-300ml-white_p0628965 on the Bunnings NZ site @johnblades.
