How to raise a cubby house off the ground for a sandpit beneath?

[globetrotter]

Hello,

Have purchased a cubby house and would like to raise it off the ground to a height of about 1m as I would like to incorporate a sandpit beneath. Have a few ideas in mind but not exactly sure which approach would be most ideal and wanting some advice/recommendations. The cubby house is 2.7m x 2.5m. My intention is to have 9 posts dug at a dept of 600mm and at a width of 180mm using 90mm x 90mm H4 treated pine posts. To build the subfloor I was going to have two bearers and about 5-6 joists. Am not exactly sure which way the bearers should run and how they should attach to the posts.

Also how should the joists be attached to the bearers, just nailed in on an angle, bugle screws or joist hangers?

And what would the recommended size of the bearers and joists be?

Tagging @MitchellMc for ideas.

Picture below is the idea that I have.

Thanks in advance

[MitchellMc]

Great stuff, @globetrotter and Happy Easter to you too!

If you have a router and want to construct stairs with rebated stair treads, you can recreate something like the Stringer Kit H3 Treated Pine 5 Tread. Alternatively, a more simplistic design would be by attaching 66 x 42mm 5.4m F7 H3 Treated Pine Primed LOSP onto the stringers and having the steps sit on top. This would be similar to your inspiration image above. If you were going this route, I'd recommend doing an X of bracing under the stairs to tie it all together and add rigidity.

I've put together a couple of images below to illustrate.

Please let me know if you have any questions.

Mitchell

[globetrotter]

Hey @MitchellMc , you wouldn't believe it but I'm not quite done. The project got bigger and bigger. One final ask, I've got to put together some windows frames and so I bought some MDF DAR Primed 30x12mm. I intend to butt join the ends because I'm getting lazy and tired however unsure on how to join them as the timber is quite thin and it would rip if I drove a screw through it. Is there any easy way to join the ends together?

Also is there perspex I can buy for the windows ?

Thank you

[EricL]

Hi @globetrotter 

Hang in there, you are making progress and soon the project will eventually be finished. Have you already cut the timber? Would you consider changing it to a Porta 30 x 18mm 2.7m Primed Finger Jointed Pine DAR which is less likely to split. But if you have already prepared the pieces, I suggest drilling pilot holes and countersinking them to prevent splitting the wood. I propose using Zenith 4G x 20mm Zinc Plated Hinge-Long Thread Countersunk Head Timber Screws in combination with Selleys 100g Liquid Nails Construction Adhesive. The adhesive serves as support to the screws. I'm afraid this is the only way to secure the timber pieces together.

Perspex is available at the store; however, you'll need to trim them down to size. I suggest having a look at your local store as there are a few sizes to choose from.

Please keep us updated with your progress, we look forward to seeing the cubby house ready for use.

Eric

[globetrotter]

Hi @EricL,

Ah I knew I should have asked before buying and cutting up the MDF. Is the Porta DAR better for what I'm doing? 

Thanks for recommending the screw length and glue.

Pictures of the completed job will be coming soon.

Thanks, Warren

[MitchellMc]

Hi @globetrotter,

Actual timber like the Porta DAR excels over MDF when screwing into the end grain, as once pre-drilled, it's less likely to split. The fibres in MDF are only glued together, and it has a tendency to split when screwed into the edge. Just make sure you pre-drill before screwing into it.

Please let me know if you have further questions, and I look forward to those images.

Mitchell

[globetrotter]

Hi @MitchellMc ,

Ok rookie mistake on my behalf. It does make sense as I cut the MDF, it does not have the same texture as pine does.

Wish me luck the wood doesn't split.

Thanks, Warren