Hi Workshop crew,
I’m dealing with erosion under my house and would really appreciate advice from anyone who’s tackled similar terrain or structural challenges.
The issue is beside a central pillar — the other side was treated with Shotcrete and drainage and has held up beautifully. Unfortunately, this side wasn’t reinforced at the time, and after two years of worsening erosion I’ve excavated the area and uncovered three key issues:
1. Waterproofing the back wall
The house wall is exposed down to the footings. I’m not planning to backfill — I want to keep a walkway between the retaining wall and the house for inspection and access. What’s the best waterproofing method or product for exposed below-ground walls in this setup?
2. Retaining the Clay with Drainage
The clay has slumped and needs to be retained. I’m looking for a solution that’s DIY-friendly but solid, with proper drainage. Access is tight under the house, so ideas that work in confined spaces would be especially helpful.
3. Rock Wall Stabilisation
There’s a natural rock face that’s part of the area that started to cave in. I’m considering installing mesh to hold it back the rest just in case it starts. Has anyone done this themselves or found a cost-effective solution that works in this type of space?
I know Shotcrete would be ideal — it’s proven itself on the other side — but it’s been hard to find someone willing to take on a job this small without a hefty price tag.
Would love any advice on waterproofing products, retaining wall systems, drainage tricks, or mesh solutions that have worked for you. Photos or links would be amazing!
Thanks in advance — keen to get this stabilised before heavy rains arrive.
Photo 1. Before I dug it out
Photo 2. After being dug out.
Photo 3. Where I need to retain, you can also see Shotcrete retaining wall with correct drainage on other side of pillar.
Photo 4. The natural rock retaining wall.
Photo 5. Tight access, plus you can see Shotcrete retaining wall before the central pillar.
