I'm in the process of building a 9x12 shed that backs onto a small hill. I plan to create a foundation that's about 30 inches high at the back wall, stepping down on the sides. Ideally, I'd love to have a slab on grade for the floor, but due to costs and the site access, a floating floor with joists and beams seems more practical. However, I can't find any design ideas for integrating a floating floor within a foundation. Most examples show either a traditional slab or a floor that sits directly on top of the foundation. I'm trying to keep the overall height down. Is this type of design uncommon, or am I overlooking something?
4 Answers
It could be a lot of work, but it’s certainly doable! You might want to dig deep for your posts, but I’d shy away from using pressure-treated wood buried in the ground for long-term. Instead, consider concrete pillars. If you're building on a hill, it can be tricky with gravity wanting to push everything down. One approach is post and beam construction with galvanized tubing. Just make sure to secure everything well to handle the weight and uneven soil. You might need to do some leveling using pit run rock to create a flat base for the shed. I had success with this method before in a similar situation!
It's crucial to think about water drainage here. If the hillside sheds water onto your wall, and if that wall supports a floating floor over gravel, you could end up with water issues. A good drainage plan is essential, so make sure you've got that figured out!
Yeah, proper drainage is key before anything else. A vapor barrier could help too!
When I bought my place, it had a shed just sitting on some bricks without any foundation integration, and it’s held up fine for years. So it totally can be done without the two being intertwined!
You might want to consider using a 4-inch concrete slab reinforced with metal wire mesh along the perimeter. Use a half-inch expansion joint between the slab and walls. Make sure your walls rest on a solid footing – at least 18x10 inches will work depending on the load. Remember to check local building codes for any specific requirements!
That’s a solid point! I hadn't considered the water drainage problems. I’ll definitely need to plan for that to avoid future headaches.