Cubby house base ideas?

[SxcMnx]

Hi everyone, newbie here! I'm wanting to install a Cubby House with an adjacent carport on an uneven grassed area & trying to figure out what the best option would be for the base? Hubby & I obviously have different opinions, and neither of us really have the experience so need plenty of advice. I don't know the correct "terms" for everything, so hopefully you can decipher what I mean. I've already read alot of member posts on here to try & get even a basic understanding. I've attached photos to help explain & what we're trying to achieve.

Hubby wants to put it on top of some conjoined-pallet-type structure & sit it directly on the ground. I'm wanting to build a low-level deck on small footings so it's elevated slightly & not have as much ground contact ie. less worry about drainage/rot/pest damage issues etc.

We've looked at other base options like digging out the grass, putting down weedmat & gravel, or pavers with sand etc, but we don't want a permanent solution, as we'll eventually want to dismantle or move it & replace the Cubby with a trampoline. So I want to keep the grass/ground underneath the structure.

Can anyone tell me what the pros/cons are for both options? Or have any other suggestions? Is it possible to just have the whole thing sitting on pallets on the ground? Or a timber sleeper base? Can you build a deck on small footings without having to cement in the posts?

Thanks in advance 🤗

House with adjacent carport idea

Flat base straight on ground idea (or on pallets)

Slightly elevated on footings with a couple of steps.

Or could we do something like this? Would this be ok?

Thanks!

[SxcMnx]

Hi @Sighman,

So we ended up totally changing ideas. We bailed on trying to join 2 cheaper cubbies & just purchased a larger pre-fabbed one that had it's own floor. So now that the base wasn't really going to be seen, we no longer cared about the "decking" look.

We ended up digging out the grass, but leaving the ground with a slight fall for drainage/run-off. And then we built a raft-type structure with the treated pine sleepers, and used offcuts to make 200mm x 200mm & 400mm x 200mm "feet" blocks to raise it up a bit more. We then cladded all the edges with treated pine fence pailings & painted the whole lot with 2 x undercoat & 2 x Weathershield (bcos we had painted the cubby anyway).

It's a very sturdy/heavy base & we had a substantial amount of rain in May without any sinking/movement so far. We are on clay though, which may/may not make a difference? It's held up to both my partner & I and our toddler playing in the cubby, plus the cubby itself obviously (so 200kg+). We're only hoping to get about 3-5yrs out of it anyway. Here's some pics I took along the way. Happy building!

 

 

 

[MitchellMc]

That looks fabulous, @SxcMnx! Well done.

This would make an excellent entry into our Australia Best D.I.Y. Project competition. Would you like me to enter it for you?

Many thanks for sharing your excellent results.

Mitchell

[Sighman]

Looks awesome @SxcMnx - love what you guys have done there. How many months/years has it been? 

Thanks @MitchellMc for the advice. The soil has already been compacted 2 years ago when i had landscapers in to lay the grass. But yeah i will compact it again with the tamper.

I was considering pouring in concrete footers, but i wasnt sure if this was overkill. For now i'm thinking large pavers so i can maximise the distribution of weight.

For drainage, is it as simple as slanting the soil slightly? Or is there more to this?  

[KatieC]

Hi @Sighman,

Thank you for the question about drainage, @MitchellMc will be back online Friday so in the meantime let me tag @EricL to see what advice he would give. You can also check out this How to install garden drainage article that our member @Adam_W wrote. Do you have photos you can share of the area you are looking to build on?

Katie

[EricL]

Hi @Sighman

The decision to put in concrete footers or pavers depends on how long you intend to keep the cubby house standing in the area. The drawback to a concrete footer is that it is very difficult to remove compared to a paver that can be simply lifted out of the way. If your cubby house is heavy enough, there will be minimal movement, but if it needs to be anchored down, then you've no choice but to use a concrete footer. 

One of the things that need to be controlled in a slope is soil erosion. This is done by putting a weed mat over the soil and gravel over the weed mat. For superior control, you can use geofabric, this has the best form of filtration and will let very little soil pass through. The only other thing that comes to mind is that the drain coil must be properly aimed outside or towards a designated drain area on your property.

If you need further assistance, please let us know.

Eric

[Sighman]

Thanks @EricL!

I was also thinking of using h4 sleepers instead of pavers so that I can distribute the weight load more. What are your thoughts on that?

And yes, good idea with the weed mat and gravel, I will be doing that.

[MitchellMc]

Hi @Sighman,

You could likely use sleepers. I know in the United States they quite often use them to build decks over soil. I don't see why they wouldn't work as a base for your cubby house.

Mitchell