Summer house/canopy in small back garden

tsuzmir

Hi all,
I am getting ready for my largest ever (partial-) DIY project.
Current state: a 3mx2.5m shed in good shape and a grass
What I want: pretty much this https://vanviegen.com/webshop/projecten/houten-overkapping/overkapping-beneden-leeuwen/
Area to cover around 6m x 3.5m
The plan is:
Dig out 15cm deep square (that's over 3m3 <!!!> of soil, some will be used to create raised beds), will with hardcore, pour concrete - that's my job
Then I have a local carpenter to put up 8 posts and a roof.
That's probably as much as I will get done this year
Next step for me will be to put up the walls: the plan was to do 2 sides and back, but I need some storage space too, so I will enclose space 2 poles wide to create a shed.
One thing I want to do, is to have this structure strong enough to hang a swing on opposite side of the shed. This will mean, the poles will be rather decent size like on the picture and I think they will look class!

I am looking for ideas how do I build the shed and side/back walls so they are well fixed in place, but do not cover the poles? Also, what should I do about flooring under the shed? the open space will be porcelain tiles.

Lumen

tsuzmir wrote: »

I am looking for ideas how do I build the shed and side/back walls so they are well fixed in place, but do not cover the poles? Also, what should I do about flooring under the shed? the open space will be porcelain tiles.

I would nail a batten down opposite sides of each post, and then nail/screw the cladding to that.

The spans are quite large, more like fencing than cladding, so the fixings need a bit of care. Nothing smaller than 2x2 for the battens, so that your fixings are at least 20mm from the edge of the battens and cladding. Use pilot holes to avoid splitting the wood, and allow appropriate expansion joints between the ends of the cladding and the posts, and between each cladding element, if you're butting them (as opposed to lapping). Not sure if you are cladding both sides or just one.

IMO it will look better if the cladding is not exactly flush, but recessed a bit to make a feature of the posts.

I would consider using the void where the battens are to diagonally brace the structure.

The quality of this project will come from attention to detail and choice of materials.

tsuzmir

Excellent points, thanks! Definitely want them recessed to expose the structure.
'I would consider using the void where the battens are to diagonally brace the structure' - you're talking to a noob - no clue what that means

Lumen

tsuzmir wrote: »

Excellent points, thanks! Definitely want them recessed to expose the structure.
'I would consider using the void where the battens are to diagonally brace the structure' - you're talking to a noob - no clue what that means

Rectangles are not stable; regardless of the strength of the members, you can push a rectangle over and it becomes a parallelogram. Diagonal bracing stops that.



In a modern timber framed structure, sheeting (e.g. OSB) is used to provide this bracing, providing what is called "racking strength".

In a traditional post and beam structure there are bracing members like in the example you posted...



...because sheeting is a modern invention, but it depends on what the carpenter has in mind.

The battens I've suggested create a void behind or between the cladding that you can use for additional diagonal bracing.

TBH since you're employing a professional I would take advice from them.

tsuzmir

That makes so much sense. I'll now know to watch out for this, wouldn't even ask that question otherwise.

So if the walls/cladding are thin, we'd use 2 sides and bracing in the middle to hide it where both sides are visible - will check for details with the builder.

Lumen

I'm really just pointing out that the approach to cladding, framing and foundations needs to work together, structurally and aesthetically, and that details matter.

Mortice and tenon corner bracing in a traditional post and beam structure takes some skill and effort, and depending on how much you're paying him he may decide to get the stability simply from concreting the posts into the ground, or from bolting bracing to the inside of the corners, neither of which will look as good but both of which will work, structurally.

Make sure you agree the details so that you are happy with the finished result, particularly since you are only paying him for half the job, so the responsibility is split.