CocoCabin - my new studio, shed, workshop build

I designed a simple wheeled unit using just under 2 sheets of 18mm ply. As it's just for the shed I just got all purpose hardwood ply from Selco, rather than the birch ply I'd usually use for furniture making.

Wheels on the bottom means that I can store it against the wall, and then easily pull it into the middle of the space to work around a piece.

I left the design open at the back so drawers can be accessed from both sides.

In this instance I even had the boards cut at selco so I didn't have to get the plunge saw out

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Are the recessed joints the only thing keeping it from folding sideways?

With the two sided access i mean.

Yes the dados are glued and screwed

I am midway through something similar and am poised with a quote from Cladco for roofing, but am unsure about a couple of details, then I stumbled across this last night, can I tap into your experience and ask you for some insights? My roof so far is the same as yours: rafter -> 11mm OSB -> membrane.

How big were your purlins? I have to keep under the 2.5m height and it is getting tight. Installation guides for metal roofing often seem to use 2"x4" purlins but I am wondering about 2"x1" to save some height. Yours look like they might be on the smaller side too?

Did you think about counter battening under the purlins for the drainage channels down the roof? I can see the logic of this, but it adds height, whereas surely there is not that much water going to get under the roof such that it'll pool up against a purlin.

When a Cladco fixing screw says it is 45mm is that the total length of the screw, or the length of the thread under the washer & head? Like you I am trying to work out how to make sure I don't screw through into the interior, I can see why using massive purlins in appealing here for a big margin for error.

Great write up, I enjoyed the details, lots to learn from, and it is a really slick result.

oh and having read what you said about planning permission - really wish we'd seen that first and given it a go. Just an extra 20 or 30 cm of height would have been very helpful.

2x4 for purlins seems massive! Do you have a link to the install specs?

If you have rafters & osb, I'm not sure why you'd need purlins at all - just battens for attaching the cladding.

Cross-battening for channel cladding would be to allow airflow, rather than water flow. If your cladding is corrugated, though, I don't see any need.

Agree with this. Corrugation does the job of cross-battening. There shouldn't be running water under the cladding but you do need adequate ventilation to stop moisture buildup. The ridge capping/detail should allow airflow too.

Thanks for these thoughts, righto, to be fair to cladco, they spec just 50mm wide, and do not mention depth:
https://www.cladco.co.uk/how-install-your-roofing-sheets

I read a PDF on PlanWell's website (similar company and products) that the horizontal battens/purlins should be at least 50mm square:
https://planwell.co.uk/core_files/fixing_guide.pdf

I then took that plus pics of people building massive barns and ended up with this concern that I needed 2x4!

This is one of the articles I read about the water build up issue with just horizontal battens on a low pitch roof (ours is 1 in 20), advocating the vertical cross-battens for a drainage channel:
https://rcimag.co.uk/sandtoft-blog/construct-watertight-low-pitch-roof-part-1

But I am glad to hear your thoughts that counter-battening is not needed. After all people use this metal roof as a single skin, so it cannot be that damp under it. And we keep telling ourselves this is a shed not a house - when learning what to do from internet blogs/videos I do get drawn down the path of full-on house construction but lack the experience to know when that is overkill.

So if I use 2"x1" battens - 50mmx25mm - plus an 11mm OSB roof sheeting then that is 36mm. Cladco's shortest screw is 32mm (and I am assuming that is thread length, not the total length) and that would screw into the OSB but not through

But, without counter-battens, I think there is just enough height to use something like 50mmx38mm then the screw does not go through into the OSB, which seems helpful in case of a slight leak around a fixing head?

SO...

as the above had said the corrugations take care of venting the space for you so I don't think counter battening is necessary. I was also trying to minimise the bulk of my cladding so I went smaller. Selco do treated roof battens in 50x25mm and 32x19mm. I went for the latter against Cladco's advice.

Bear in mind that they stamp these sheets out in lengths up to 6 metres, and people install is on steel frame agricultural buildings as a single skin with no board sheathing to add rigidity underneath. If you had a 6m x 1m length of this stuff it would weigh a ton and you would definitely want the supporting battens to bear some serious weight. For a 2mish shed it's really not a concern.

My walls are 2.4m to the eves so I ordered the wall sheets in 2.4m lengths and I spaced my battens from the bottom every 60cm up. So there was 5 horizontal battens across the height of the walls. My rafter legnth is 150cm ISH so I did 3 battens, one at eves, one at ridge and one across the middle. I then secured my sheets down every 4th corrugation.

Fixings -
CladCo recommend the 65mm hex screws that have the baz washer on them. These are best for the corrugated sheets as the baz washer is a big soft spring that makes a perfect seal against the curve of the cladding. However I knew that this was going to be too long for my walls so I used their 45mm screws which come fitted with a bituminous washer, designed for making a seal against their flatter box profiles.ive found this to be perfectly adequate and driven in straight they give a good seal. 11mm OSB plus 19mm batten plus 18mm for the profile of the cladding itself (the fixing always go in at the 'ridge' of the corrugation not the 'trough') plus the 2-3mm of washer and bitumine gives you about 50mm – plenty of meat for your screws.

Get a good 8mm hex driver it makes the world of difference!

Thanks! This is great advice. Some replanning happening here...

Lightweight battens, horizontal only, for vertical efficiency win

We were going to get the 32/1000 box profile. I had just assumed the corrugated one would be taller, like agricultural sheets. But 18mm!! More vertical efficiency winning. We'll now use that. (Plus, it looks a bit similar to the wavy concrete tiles the houses in our estate have, plusplus my partner is a kiwi by descent and corrugated roofs are in her blood)

And we are now going to clad the window-less sides that abut the boundary fence and the garage with the same stuff. I was put off cutting the angle for the side eaves, but I am now up for giving it a go, having read your posts. It has obvious cost/time benefits over wood cladding.

The garden and house side will then still get wood cladding, which we will leave to fade to grey-ish to sort-of match the house a bit (60s yellow brick). We've already ordered white windows to also match the house. If we deployed cladco+black windows on those sides too we're worried we'd end up with an architectural masterpiece like yours and we'd regret buying our actual house and end up just living in the shed! These sides have windows, so with the cost savings from doing the other 2 sides in cladco, we can hopefully find and afford a nice hardwood cladding (drove off today to admire a shed I had seen in passing, and found the owner outside, it turned out to be oak so quite tempted by that)

After a little brexit dividend, where Cladco's stock of what we'd ordered (Anthacite 13/3 7mm plastisol-coated) got stuck in a container somewhere, they kindly found us some Graphite Grey in the Prelaq-Mica finish and covered the extra cost themselves, but then the usual Christmas delays, and finally after all that, it arrived this week. I got started today, here's a pic from the back corner of the first sheet up.

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@sifriday only just saw your last post. Looking great, all done now?

yep! the cladco is all done, but a bit more to go on the rest.

January - finished off the Cladco for the roof and 2 walls
February - gutters and water butt for the garden, found an electrician to wire it in properly to the house and built a wood cladding detail around a window to work out what to do, then took it all off again...
March - Window trims/linings done last weekend, then I started the wood cladding itself just this weekend. It will be slower going than Cladco, so am glad it is only 2/5ths of the surfaces.
April? last few jobs... finished!

Back in December once it became apparent that both lots of cladding would be slow to arrive we finished off the inside and began using it - 'moved in by Christmas' - Grand Designs classic - so that has taken the pressure off a bit to get the outside done.

The cladco looks great and it all went on just as discussed above so again, glad to have coincided with your project and learnt from it. One thing I learnt was to think about the placement of fixings with respect to bargeboards in advance - I did the sheets, then found the bargeboards would overlap the fixings at the edge, which distorted the shapes a bit. I moved some around, but left some as a bodge, mostly you cannot tell from ground level, but I look out it from the garage window, which is up and behind the shed, and then you can see the wobbly apex bargeboard whenever I look out of the garage window...

How's this looking now?

And how have you found the heat in the summer?

This is exactly what I need. Any chance you have/will share plans? I know it isn't complex (to its credit.)

What are the drawers?

What are the drawers?

https://www.lfgss.com/comments/15626518/

for anyone still subbed to this ancient thread, I'm currently working on cococabin 2.0!

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How's the OG one looking now?

Did the black cladding give any heat issues?

Incredible! Is the new one the same specs as the one you initially intended ie 6m long?

Right, I’m reading this whole thing.

Any updates on the new one?