Can I use timber battens for wall framing for a cubby house?

[Raymo16]

Dear Workshop,

I am planning to build a cubby house for my daughter.

from the research I’ve done, typically the wall framing is built using a 70mm x 35mm treated pine.

i am concerned that if i use this size of timber, the walls will appear too thick (relative to the size of the cubby) and unnecessarily reduce the internal floor area.

I’m not wanting to build a large cubby. For reference, I have made a 1.8m x 1.5m base for it to sit on.

Could I build the wall framing using 42mm x 18mm pine? Or is this going into territory where stability / integrity will become an issue?

[TerryN]

Hello Raymo,I used 70mmx45mm batterns on one I did for my grandkids a good while back,as that is what was laying around on  our site.It is also close to the size that you are considering.1160mmx1250mm.I didn't put a tin roof on it though as it's under a pergola area and weather proof,although it wouldn't be hard to screw a couple of sheets onto it if needed.I just used some pine lining boards out of the skip bin to line the walls and ceilings.I used leftover treated pine decking boards for the door and floor (didn't take a snap of it as it has some off cut carpet on it.)Regards Terry.

[JacobZ]

Hi @Raymo16,

Thank you for your question about wall framing for a cubby house.

Unfortunately, you could not use 42x18mm to create any kind of supporting frame, especially if there was going to be a roof on it. Having handled thousands of lengths of 42x18, which is a profile used for timber trims, I can say from experience that they can and will snap quite easily.

The smallest profile of timber that can comfortably be used as the supporting frame for a structure is 70x35. 

Yes, you would be losing 70mm of space on either side, but for the safety of your children and your own peace of mind, this is an unavoidable loss of space.

Let me know if you have any further questions.

Jacob

[Raymo16]

Dear Terry,

Thanks for the information and photos!

[Raymo16]

Dear @JacobZ,

Thanks for clarifying! 

Would the 70x35 also be suitable for framing the roof?

[JacobZ]

Hi @Raymo16,

In house construction, you would usually use larger timbers, engineered timber products such as LVLs or prefabricated trusses for roof framing. In a smaller application like this, you can reduce the size, but 70x35 is still too small a timber to support a roof.

Manufacturers of corrugated iron sheets will call for 90x35 timbers at a minimum. I'd suggest you use 90x35 H3 framing pine for your roof.

Let me know if you have any further questions.

Jacob

[Raymo16]

Dear @JacobZ,

Thank you for this!

I'm sure i'll be back with some more questions as I try to figure out how to build this thing.

[Raymo16]

Dear @JacobZ,

I was planning on building the base for the cubby using H4 treated pine sleepers, in the arrangement suggested by Mitchell from a previous post:

https://www.workshop.bunnings.com.au/t5/Outdoor/Cubby-house-base-ideas/td-p/94618

Mitchell suggested 200 x 50 sleepers, which would result in a decent step up and not  be ideal for our yard.

I would prefer something with a lower profile. Could I use 100 x 50 sleepers, and just add more members to make it sturdy enough?

[JacobZ]

Hi @Raymo16,

Yes, you can use 100x50mm sleepers as long as they are H4 treated.

If they are in direct contact with the ground, there is no real need for additional members as they will be directly supported by the ground along their full length. As long as they are spaced 450mm apart so your decking boards are well supported, then you will be fine.

Let me know if you have any further questions.

Jacob

[Raymo16]

Thank you @JacobZ!

The ground is not level, so I am planning on placing them on on pedestal feet: https://www.bunnings.com.au/builders-edge-35-60mm-smallfoot-pedestal-feet_p2450074

I am also trying to figure out if I needed to tie down / anchor the base. Fom the research i've done, a lot of people don't seem to worry about it, however i'd rather play it safe.

I initially thought that I could use a couple of sleeper pegs: https://www.bunnings.com.au/50mm-sleeper-peg-galvanised-steel_p1100763?store=7152&gad_source=1&gclid...

But I now realise the top of the peg may affect the placement of the decking boards.

Any suggestions for anchoring the base?