I have just picked up a cubby house kit for our 2 little ones. At the moment it is just a big pile of wood, but allegedly when complete it will have a 2400x2400 floor and walls about 1500 high, so nothing too extravegant.

My question is about the floor structure. The part of the back yard where it will be built is currently lawn, with a slight slope towards what will be the back left corner of the cubby. The back left corner is about 30cm below the front right corner. For this reason I bought a 40cm "elevation kit" to work with the slope. The elevation kit is basically 8 130x80 treated pine sleeper "stumps" with notches cut to receive the floor joists. The floor itself will be made up of 5 90x45 joists at 600 spacing with treated pine floor boards on top. No bearers were supplied with the kit.

I'm having trouble working out how to make a solid floor with 5 joists sitting on 8 stumps. It just doesn't seem like it will work. My plan is to use 2 or 3 bearers sitting on 4 or 6 stumps respectively. The stumps would be mounted on concreted in stirrups or fish-plates.

Is this overkill for a small cubby house?? If I do use bearers, would 2 be enough, or would the 2400 span be too much? What size should I go for?

Is there a better way??


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