Although a playhouse generally comes with a floor, you might wonder if it needs something for the floor to sit on as well.
Playhouses need a base if they have a floor that sits at ground level. A good playhouse base can be a concrete slab, wooden decking, pavers, or even gravel. This stops the floor of the playhouse from getting damp, as well as stopping weeds and creatures from coming up through the floor.
Let’s have a look at the most popular options below. I’ll describe what each one is, how to lay it, and what the pros and cons of each are.
A Concrete Slab as a Playhouse Base
A concrete slab for a playhouse is a rectangular or square block of concrete that sits on the ground underneath the playhouse. It is one of the more expensive options, but will last longer. It will also be the best solution for a more substantial (and weightier) playhouse. Just be sure you know exactly where you want the playhouse to sit, as it will be difficult to move later.
I should point out that a concrete base isn’t suitable for underneath swings, climbing walls or tower playsets. Anywhere that kids could fall from a height, you want to have something more shock absorbing, such as rubber or even wood mulch. Please see (LINK What do you put under your backyard playhouse?)
To prepare the playhouse site for the concrete, you’ll need to find or create a level space in your yard. Measure out the size of the playhouse, and then remove that much turf. As the turf is lifted, just place it to the side. You can use the turf elsewhere in the yard if you have any patches. The ground will now be exposed to earth, ideally around 3 inches below the surface. If your soil is a little wet or uneven, you can lay down an inch or so of roadbase gravel. This will give a more uniform base for the concrete to sit on.
If you’re using a contractor, they’ll put some pieces of wood around the perimeter as a mold. For a job this size, it’s unlikely you’ll need reinforced steel (sometimes call reo). The reo is designed to prevent cracking under the weight of real houses or the movement of cars on driveways, but it is unlikely that your playhouse will need this.
The concrete needs to be poured in place inside this mold. Within half an hour of pouring, it will be smoothed out, and given an almost imperceptible slope to help rain drain and prevent water from pooling on it. It will then take a few days to cure before you can set the playhouse.
Pros of concrete as a playhouse base
- Suitable for large heavy playhouses with a ground floor
- Solid and stable
- Will stop weeds growing through the floor
Cons of concrete as a playhouse base
- More expensive
- Takes a few days to install
Here’s a video that gives a good DIY guide to pouring a concrete slab for a shed, which seems remarkably similar to a playhouse size and shape.
Wooden Decking as a Playhouse Base
Wooden decking is an ideal base for a playhouse. The playhouse will sit on decking supported by joists, and this will keep the playhouse off the earth. You can even build it a little larger than the playhouse, and so extend the ‘verandah’ for summer tea parties or pirate battles.
To lay down wooden decking for a playhouse, you will need to start by leveling the ground, removing the turf down to the soft earth level. Put an inch or two of gravel down to assist with drainage and to level off the ground, then lay out the frame. This is the last chance to really think about how big you want the decking to be.
Make sure you are using pressure treated wood to ensure longevity from rot. Commit to the frame, and then lay joists inside the frame. The trick is to ensure the joists are sitting at exact right angles to the frame, and have them around 1 ½ feet apart to support the decking boards. The decking boards sit on top, and are fixed in place on the joists with either screws or nails. You can then stain the decking to look good with the playhouse, as well as provide some extra protection from the elements.
Pros of decking as a playhouse base
- Less expensive than concrete
- Looks natural in the garden
- Can be dismantled if required
Cons of decking as a playhouse base
- The cutting and positioning of the wood can be fiddly
- It will probably need replacing after 8-10 years
Lowe’s have got a nice comprehensive video on making a wooden shed floor foundation. They also mention concrete, but spend most of their time on the wood version. They use a plywood panels, rather than decking planks, which can work if you are making the base the same size as the playhouse. If you’re making the base bigger, personally, I’d prefer to see the planks.
Pavers as a Playhouse Base
It’s pragmatic and fairly easy to use pavers as a playhouse base. Pavers give the almost as much stability of concrete, without the preparation time, and you may even have some old pavers or breeze blocks lying around that have been waiting to be upcycled in this fashion.
To lay the pavers as a playhouse base, try to find an area that is mostly level and free of big tree roots that protrude from the ground. The area should be fairly dry and well draining. Measure out no more than a couple of inches larger than the playhouse.
Start by removing the turf, and exposing the dirt at least three inches down. If you are using breeze blocks, you might want to go down a couple more inches. Check that the ground is level by using brickies string and a spirit level, otherwise your new playhouse might be sitting on a slope.
Put down a weed barrier, and then an inch or so of roadbase gravel. If you have access to a compactor, use this to push all of the rocks against each other to create a nice smooth surface. Double check with the spirit level to be sure it is still flat.
The pavers go down now. I’d suggest choosing pavers that are around 12 inches square, and 2 inches high. These are what local councils use as pavers on sidewalks. If they’re of good quality, and not cracked, they will be plenty strong enough for your playhouse. Make sure that each one is level and gently tap into place with a rubber mallet. It is important that these pavers are level.
Once you’re satisfied, brush a mix sand and cement in between the pavers and lightly sprinkle with water to finish off. This will harden, and help stop water and snow from getting under the pavers and lifting them. You are now ready to put the playhouse in place.
Pros of decking as a playhouse base
- Quick to install
- Often have materials at home already
- Relatively inexpensive
Cons of decking as a playhouse base
- Can be fiddly to get every paver level
- Heavy work
Here’s a cool video (with an English accent) to lay pavers as a base. This one is for a greenhouse, but the principles and the size are exactly the same.
Gravel as a Playhouse Base
Gravel is crushed up rocks, and when laid out over the ground, makes a quick and cheap base for a playhouse to sit on.
You could use either pea gravel or roadbase. Pea gravel is a smaller crushed stone where the rough edges have been taken off by tumbling through a big machine after crushing. Roadbase gravel is another option, but they still have the sharper edges. It is definitely harder to walk on the sharper roadbase compared to the smoother pea gravel.
If the gravel base is the same size as your playhouse footprint, then it is unlikely that you’ll see the gravel. This means the kids won’t be walking on it, so it shouldn’t matter which one you use.
I definitely wouldn’t use either roadbase or pea gravel for a base underneath any playset component, such as swings or climbing walls. These just aren’t good choices for places where kids could fall.
To lay gravel as a playhouse base, you’ll want to be on level root-free ground. Similar to the other methods above, you’ll want to remove the turf down to around 3 inches. This will then give you the firm earth. This is when you’ll want to lay down the weed barrier.
Now make a wooden frame that sits in where you want to put the gravel. Put around 3 inches of gravel down, and then top with a one-inch layer of sand. This will sit in between the cracks of the gravel, and give some abrasion to hold it all in place. Tamp it down with a compactor, and then make sure it is level.
Pros of gravel as a playhouse base
- Easiest and fastest option
- Cheapest option
- Will keep the site well drained
Cons of gravel as a playhouse base
- Can be tricky to get exactly the right footprint, dpth and the right amount of graveel
- Can be fiddly to get it level
- If you get a lot of snow melt and re-freezing, it can become quite uneven
Here’s a video showing how to lay a gravel pad for a shed (with a lovely Southern drawl). This also has a great example for how to level off a slope before putting the shed in place. You may not need machinery depending on the size of your playhouse, but it’s useful to see just how much easier it makes it.
Getting a good foundation base for your ground level playhouse will help it last longer. It will stay drier, and be more likely to be weed- and critter-free.