Lockdown Workshop Build

[Shaun92]

I’ve been threatening to build my workshop for a couple of years and I’ve finally started it.
I’ve got a budget of £1000 (ish) and it will be 4.5m x 3.2m to keep within the 15m2.
50mm Mot base
Dpm
100mm concrete slab (no reinforcement)
1 Course of block
Coated in blackjack
Dpc
95x45mm sole plate (all 4 x 2 timber has been reclaimed for free)
stud walls (600 centres)
Top plate
Trusses constructed using the same 95 x 45mm timber
18mm reclaimed ply sheets for roof
Cheap cold lay felt
Breathable membrane on walls
25 x 38mm vertical treated batten
Clad with 150mm feather edge
Internally
100mm earthwool
Vapour barrier
Reclaimed 18mm ply on walls
9mm osb to ceiling
Door and windows bought cheap off eBay + Shpock


I’ve followed several builds on this site and I want to try and add to the melting pot of information and ideas.
I don’t know if this is allowed but here’s a link to the YouTube videos I’ve uploaded, they include more images and walk arounds.

https://youtu.be/7M75gkonWXg

Any questions or ‘constructive’ criticisms feel free to hit me with them.

Thanks
Shaun

 

[MikeG.]

Welcome Shaun.

That all sounds good to me, although a description of your roof would help. It's hard to fit the necessary insulation into rafters only 100mm deep. Also, try to avoid the 150 featheredge, as it is flimsy stuff. Better to go for the ex 175x32 stuff. If you line the inside of the walls with ply or OSB there is no need for a vapour barrier. Both of those have a high resistance to the passage of vapour because of the large amount of glue used in their manufacture. Finally, 38mm counterbattens are fine if there are no joins in your boarding, so make sure your featheredge is at least 4.5m long. If you need to do a butt joint then it's better to have 50mm counterbattens.

Don't forget that the 15 sq m thing relates to internal floor area, not the slab area. I presume this means you are building hard up to a boundary.

 

[Shaun92]

Afternoon Mike,

Thanks for the feedback.

The roof is just a basic shallow pitch, trussed roof. Trusses are fixed together by sandwiching joint between two 4x2’s, glued and screwed. This method gave me a central flat section to fix lighting to.

As for the insulation in the roof, I’ll just peel off 20/30mm from the 100mm earthwool to give some air movement over the top.

I’m not going for a super efficient building, just something comfortable. I could always add a continuous layer of PIR across the ceiling at a later stage.

I’ve already got the cladding, unfortunately everything comes down to £££. Where the cladding will be jointed, a vertical 150 x 22mm board will be in between the two pieces. This detail will be supported by 4 battens, 1 taking the end of the cladding, two for the 150mm board and 1 taking the start of the next piece of cladding.
The corners are also going to have 150mm boards wrapped in an L shape. The Mrs has asked for it to look ‘New England’ style, she mentioned about adding wooden shutters on the windows too but we will see.

The reason for the vapour barrier is firstly because the ply I’m using is reclaimed so isn’t 100% and secondly (mainly) to keep out unwanted creepy crawleys which I’m not a fan of!

Lastly, the workshop is about 400mm away from the boundary at the closest point. I didn’t know that the 15m2 applied to the internals, I thought it was the buildings footprint that was measured!!

I could have gained myself a bit of extra space to store more necessary junk in the workshop.

Thanks Mike

Shaun

 

[Shaun92]

 

[Shaun92]

 

[MikeG.]

That DPM won't last long up the plinth walls. It degrades in UV light. What is your plan with it?

You're also going to need a proper lintel over the door opening, and your roof needs some ties (they aren't trusses at the moment, just rafters). And did you not want a window?

 

[Shaun92]

 

[Shaun92]

 

[MikeG.]

Shaun, did you miss my earlier post?

Lintel and roof ties are an issue. Could you comment on those, please.

 

[Shaun92]

 

[MikeG.]

That's twice. I'll leave you to it then.

-

Please, anybody else viewing this........DON'T build a roof like this. It will fail.

 

[Shaun92]

Shaun, did you miss my earlier post?

Lintel and roof ties are an issue. Could you comment on those, please.

Hi Mike,

By ties do you mean timbers stretching from the front to the rear?
If so, I’m waiting on some more timber to become available and then I’ll add a few from front to back.

I don’t need them at every “rafter” :wink: do I?

As for the door needing a lintel, that was a cockup on my part, I jumped at a cheap door I found and it was about 60mm bigger than what I’d planned for. I had to chop out the top plate so I’ve reinforced it on the inside, fixing a timber across the head of the door into the studs either side and fixed into the 3 rafters over the doorway.

I’ll take a picture tomorrow and you can give me your opinion on the cockup fix.

Shaun

 

[Shaun92]

That's twice. I'll leave you to it then.

-

Please, anybody else viewing this........DON'T build a roof like this. It will fail.

Sorry mate, I wasn’t ignoring you. I was trying to upload pictures without having chats in between so it’s easier to see the progress.

It’s a lot of faff adding each picture.

 

[MikeG.]

.......I don’t need them at every “rafter” :wink: do I? ...

No, not if you aren't storing anything on top of them. I'd put one on the rafter pair to the right of the door as you look at it from the outside, which will help stabilise the dodgy chopped away plate situation. You may only need one other, but 2 evenly spaced would be on the safe side.

 

[Shaun92]

Yeah I’ll do that, didn’t have and decent timbers longer than 2.1m which is also why there’s half laps all over the place

On to cladding this weekend!

 

[Shaun92]

 

[Shaun92]

Link to an update on the workshop build.

 

[Jameshow]

Nice build

If the door frame droops due to the weight of the roof you could use a length of angle steel as an improvised lintel.

Did you put the ties in as suggested above.

Otherwise the roof will tend to sagg.

Cheers James

 

[Shaun92]

Nice build

If the door frame droops due to the weight of the roof you could use a length of angle steel as an improvised lintel.

Did you put the ties in as suggested above.

Otherwise the roof will tend to sagg.

Cheers James

Hi James
Yeah the workshops got ties installed now, I haven’t had and issue over the door. I added braces with some more timber but your suggestion of angle iron is a good one which I’ll use if I get any issue in the future.

 

[placks]

Don't forget that the 15 sq m thing relates to internal floor area, not the slab area. I presume this means you are building hard up to a boundary.

Hi Mike

Another new poster here doing research for a similar build. I'm getting a bit confused by the 15m2 thing and building regs.

So if your internal footprint is 15m2 or less then you can build out of wood as close to a boundary as you like?

if its more than 15m2 it has to be over 1 meter from any boundary and if its not it has to be made from non combustible material?

Have I got that right?

Thanks
Ryan