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Hello all! I am planning to build a small wooden storage shed as a project to gain some carpentry skills. It will be approx 3.5m wide x 2.5m long (Staying under the limits of permit requirements where I am in Victoria). I am on a sloping block and have had a small area cut into the slope, and one side built up to level it by an excavator (See attached images).
Essentially, the built-up side is quite soft so I don't think I should use the concrete foundation blocks that are often recommended.
I've been looking into multiple options, I was initially sold on a gravel pad (This article was very persuasive and helpful and this video too) but I'm now also exploring options for some footing, similar to what you would use for a deck but there are so many options I'd love the community to offer some ideas based on the area I have.
I was planning to dig some holes and use those cardboard footing tubes and pour concrete in and then use some kind of bracket to attach some lengths of 90x90 treated pine as the basis on which to build the shed floor joists.
I am open to pouring a concrete pad but I'm not a huge fan of the permanence of it (or the cost!) but I'm not against it if it's the best solution.
I also think I should retain the left side where it has been cut into. It's not very high approx 300mm, a single sleeper would probably do it. Suggestions on a simple approach to this would be welcomed. I expect if I go the gravel pad route then this would just be one of the sides of the container for the gravel.
So, to summarise:
1. Which solution would be favourable for this size, area and ground, factoring in cost/simplicity? Gravel pad, footings (and what kind) or a concrete pad?
2. What approach should I use to retain the side that has been cut into?
Thank you all so much!
Hello @mikebarker,
Building your own shed sounds like an exciting project. Let me tag our resident D.I.Y. expert @EricL who should be able to assist you with your questions about the shed foundation when he's back online later today.
In the meantime, you might be interested in checking out these related projects and discussions:
Keep us updated as your project progresses. We'd love to see the final result.
Akanksha
Hello @mikebarker
I'm leaning towards building a concrete slab. Aside from the long service life, building it would not be as involved as building a frame with the proper amount of support at the bottom. Not only that, but you'll need to calculate the weight of the timber shed your building to go on top of the timber frame. All of this can be bypassed by building a concrete slab instead.
However, the size of the slab your about to build is bordering on the limits of D.I.Y. In this particular situation, I suggest doing a compromise. I recommend preparing the soil, building the timber frame for the concrete and placing the re-enforcing mesh yourself. I then propose engaging the services of a professional concreter to do the pour.
This will guarantee two things, the slab will be at the correct level and will have a proper slope. The slab will have a professional finish. Aside from these, getting a professional to do the pour means that you won't have to purchase any concrete or specialty tools.
Once the slab cures you can begin constructing your wooden shed.
Let me call on our experienced members @Adam_W, @TedBear, @JoeAzza and @Dave-1 for their recommendations.
If you have any other questions we can help with, please let us know.
Eric
Love your yard! And loving the idea of a shed. What type of shed are you thinking of building? I checked out the gravel base link that you posted but I am not sold on it yet (I like the idea of drainage that you would have and will watch the video later as I am in the office, but shhhh 
)
Have you seen the Post screws Bunnings sell?
90*690 Post screw I am considering using these next time I build a deck or fence even. I want to give it a go as they look like they will support without being permanant. They may be suitable depending?
With the amount of pine needles you have I think gravel might clag up easily. I do like Erics idea of a concrete slab and the prep done by you but thats a permantant slab (Since breaking up old concrete paths I have really changed my idea on concrete lol)
Another question I have is that your fenceline next to the excavated area?
I am not sure if we are allowed to post outside links here but I have seen these type of foundations (I like them especially as they dont need concrete and are not going to damage trees as much. Diamond Pier I have seen them before under another name. )
As for a retaining wall/something to stop that soft soil moving I would suggest a gabion wall. They are non permanant, solid and will allow water to pass through. Bunnings sells the premade baskets that you put together in various sizes. I have used a few of them and have found no issues.
Gabion basket search (Just look gabion baskets in the search panel and you should see soem of mine)
I want to build a garden shed one day, I am lucky that the ground where I live is compact but have considered the concrete blocks you mention. The screws I have mentioned and the last is to actually have just a supporting structure for a roof and walls and actually pave the base.
Looking forward to seeing what you decide. I usually spend weeks figuring out what to do and the steps required as sometimes the steps knock the idea on the head.
Dave
Hi @mikebarker,
Let me tag @MitchellMc for his thoughts.
We also have a guide How to pour a concrete slab by @tom_builds if you might like to consider doing it yourself.
Jason
The 800mm is the minimum distace a structure can be from my fenceline in NSW (Yeah I know I broke that rule with my last build 🐵 Your council should have it listed on their website. If you look at the privacy screen I have built, it could easily be used to store a mower ect and it all sits on 5 posts.
I do a LOT of sketches while having a coffee to figure things out Its a good excuse to sit in a cafe!
Dave
Hi @mikebarker,
You have a couple of issues here. Your ground not only slopes left to right but from front to back. The slope is effectively on a diagonal to your proposed location. Secondarily, instead of digging down to establish a flat plane, you've added soil from the left-hand side to the right to minimise the depth you had to dig. I don't blame you; it's hard work. So, now we have piled up loose soil on the right and back of the proposed shed area.
You need to retain the soil on all four sides before compacting the central area. I've created a rendering below to illustrate. The sleepers on the right and at the back stop the soil from failing away down the slope, and the sleepers on the left and front stop the soil from slipping down the slope and into the shed's footprint.
Once you've stabilised all four sides and compacted the retained soil, you're free to create whichever style of base you'd like. The key issue is stabilising the ground. Without the soil being adequately retained you can't compact the area; without compaction, nothing will be stable, whether that's a gravel, concrete or timber base. Any compaction you do without the retaining walls will cause the soil to slip down the slope.
Get the base right, and you'll be ready to use whatever footers/base you like. I'd recommend adding 100mm of gravel, compacting the area, and then using DEKO 250 x 150 x 150mm Instant Concrete Foundation Blocks with your timber frame on top.
Please let me know if you have any questions.
Mitchell
