Workshop DYI build plan - feedback needed

[tibi]

Hello,

I would like to build my own workshop with size 4x4 m. The attic of the gable roof will be used as a storage area for unnecessary household items. I used to work as a self-taught engineering CAD designer, but I have little to none knowledge of timber construction, structural engineering and stress analysis, that I would be given in technical school.

I have created my own plan, but I have no idea if there are any design or structural flaws. I have constructed the workshop in a way that I can build it alone, except for erecting the queen trusses, where I would need a helper. As I cannot calculate the minimal cross-sections that are required, thus I have made deliberately the building more rigid.

All the joints will be made either by rigid connector angles and plates or two wooden members screwed directly with Torx wood screws.

Any feedback is appreciated.

Thank you.

 

[DBT85]

Lovely set of plans you have there Tibi. Apart from the usual back and fourth about what base to build it on, my only real thought is that your walls need a fair amount more studs. You appear to have them on very wide centres. Typically (at least in the UK and US, I guess its the same everywhere else), you'd be looking at 600mm centres or if you're really worried about it, 400mm. Now that is in part due to the fact that we use sheet goods to clad them (inside or out) that ship in 1220x2440 sizes. Structurally I don't know if the NEED to be that close together, however.

Another note would be to move the door 300mm or 600mm away from the adjacent wall. If you put it in the corner, you now cant store anything on (assuming a 0.9m x 2m door ) 3,6m of wall area. If the door is inset a bit you now only lose the actual door area of 1.8m. I think there are also structural considerations there.

 

[Fitzroy]

Read the sticky ' Build a shed Mike's way ' . Your plans use non standard timber sizes. The timber size you need is dependant on your spacing, distance between for your floor joists, and then span tables can be used to determine max span, and timber size. Framing will sensibly be 4x2 treated timber and then 600mm stud spacing, or 400mm if you want to over engineer, then take a look at some youtube videos on how you frame around windows and doors.

I used a pent roof on my shed build so have nothing useful to add on how to design roof trusses, but expect there will be info on youtube/the net on using standard size timbers and then general rules on distances and frame spacing.

Designing without using standard timbers sizes and spacings and standard construction approaches will require structural calcs and a structural engineer, that will get expensive fast.

Fitz.

 

[Jameshow]

I agree more studs less noggins - horizontal members.

Cheers James

 

[RobinBHM]

Hi Tibi, your drawings are fantastic, great to see detailed CAD drawings.

Although you have shown lots of detail of the framework, in actual fact it's only a part of the story.

Instead of the horizontal timbers (noggins), as others have said, space your vertical studs at 600mm or 400mm centres. If you put sheathing plywood or OSB on one side, then noggins aren't very important.

Also for a weathertight and long lasting structure, use breathable membrane around the outside, then screw on 50 x 25mm battens vertically on the studs, then fit your external cladding. Those battens create an air gap which allows any rain getting through the cladding to run out, keeping the structure itself dry.

 

[RobinBHM]

In case anybody hasn't noticed the OP is from Slovakia so timber sizes, construction terms and detailing nay differ

 

[tibi]

Thank you very much all. Actually, I have a neighbour at the lumber mill, so he will cut me any size I want, I am not limited by any standard sizes, metric or imperial.

I will remove the noggins and add more studs at the 600 mm spacing. Also, move the door out of the corner to create a space for some shelving - nice idea. And I will try to get a quote from a local structural engineer for consultation. If the price is too steep, I will ask some local structural engineer in India or similar.

 

[Fitzroy]

In case anybody hasn't noticed the OP is from Slovakia so timber sizes, construction terms and detailing nay differ

Oops missed that. Apologies for my less than helpful post in that case.

 

[Jameshow]

Oops noggins might not translate the same in Slovakian!!

Cheers James