I own an old house with a room corner that sits a few inches below street level on a sloped street. There's no damp proof course, and I've noticed the bare bricks become damp up to about a foot. It's just the street outside, and I don't see any specific water sources apart from regular rainfall. I've tried covering the area with plastic and was planning to attach rigid insulation before adding drywall. However, when I checked last, the inside of the plastic was wet. I'm worried about mold forming if I leave it like this. I suspect that the sand-cement used outside traps moisture, forcing it inside. I'm considering leaving a gap between the insulation and the bricks for ventilation, maybe even drilling holes higher up for airflow, but I'm concerned that the battens would get moldy. What should I do?
2 Answers
It sounds like you're dealing with some tricky moisture issues! First off, it’s good that you’re thinking about airflow. Diverting any rainwater away from the wall is key. You might want to create a slight slope away from the house at the street level if that's possible. And yes, drilling holes higher up can help, but make sure they’re not in an area that would allow water back in. Just be cautious about keeping wood away from any constant moisture to avoid rot.
Leaving a gap is a decent idea for ventilation, but you might want to consider using materials that are resistant to mold for the battens. There are also breathable membranes available that can help keep moisture at bay while allowing air to circulate.
Great point! Investing in mold-resistant materials can make a big difference in preventing future issues.
You mentioned the droplets; while they may not be a stream yet, it’s smart to address it before it gets worse. You could explore adding a drainage channel outside if conditions permit.