Converting a new shed to a workshop….by a newbie

[Jfw2708]

Afternoon all, so having set up my new workbench and starting off woodworking in my garage, Mrs W is booting me out as it’s too dusty and gets sawdust all over her nice gym stuff. So I’ve taken down our old decrepit shed in the garden and bought a new 10 x 6 replacement Tiger Sheds Workshop shed. It will be on the concrete base the old one was on and is fixed in size (id love a bigger workshop but that isn’t an option so we crack on). Anyway I’ve had a root around on here in terms of things to do so have some ideas. Plan is to use some Rockwool (maybe 30mm or so) and then OCB board out and paint. But i have some questions that hopefully the good folks on here can help with and also point out what i have missed. For context it will never be anything other than a man cave workshop for me, wont be slept in or converted into anything else (well by me at least). So some thoughts:
1. Do i put a waterproof membrane down between the concrete base and the shed?
2. Do i need to put in a vapour barrier and if so on what side - against the shed wood with the insulation on top of it, or on top of the insulation then board over it…or neither
3. Is 30mm of rockwool and OSB ok?
4. what sort of ventilation will i need?
5. It’s non-tantalised wood which im planning to wood preserve then paint….anything to consider there?
6. What type of insulation will need to go on the floor?
Any other tips in putting it up and then fitting it out?

Any thoughts on the above more than welcome. Thanks in advance

Jules

 

[Jameshow]

1. Do i put a waterproof membrane down between the concrete base and the shed?

I would as water will gather.

2. Do i need to put in a vapour barrier and if so on what side - against the shed wood with the insulation on top of it, or on top of the insulation then board over it…or neither

I wouldn't...

3. Is 30mm of rockwool and OSB ok?

I would use 25mm polystyrene / celotex

4. what sort of ventilation will i need?
5mm gap would be fine.

5. It’s non-tantalised wood which im planning to wood preserve then paint….anything to consider there?
Preserve and stain.

6. What type of insulation will need to go on the floor?
I'd put it under the floor between the joists.

Any other tips in putting it up and then fitting it out?

 

[artie]

1. Do i put a waterproof membrane down between the concrete base and the shed?

I'd raise the shed on runners, just an inch or two unless there's standing water.
Waterproof membrane works both ways, a fact often forgotten.

3. Is 30mm of rockwool and OSB ok?

What size is the framing, I'd maximise the insulation to the framing size.

4. what sort of ventilation will i need?

A very good question. An insulated wooden shed can get very stuffy, I'd recommend two adjustable vents, one on either end, then you can adjust to prevailing conditions.

5. It’s non-tantalised wood which im planning to wood preserve then paint….anything to consider there?

Use the best you can get/afford.

6. What type of insulation will need to go on the floor?

I'd go with thickest polystyrene I could get between the floor joists.

Any other tips in putting it up and then fitting it out?

Take a minute to figure out how many extra battens you'll need to carry the osb and fit them before you erect it. much easier.

 

[Jfw2708]

Thanks both, handy tips. Ive gone for 55mm deep framing so there is a decent amount. On the base it does come on wooden runners so hopefully that will be ok.

 

[Jameshow]

Thanks both, handy tips. Ive gone for 55mm deep framing so there is a decent amount. On the base it does come on wooden runners so hopefully that will be ok.

Go for 55mm then with a 5mm gap. The t+g will keep most weather out anyway.

 

[themack]

As I just put up a shed on a concrete base...
I put DPM underneath the shed bearers. They come in strips (Screwfix), so easy to cut and lay. I made a mistake with the concrete base being larger than the shed along the sides and as I live in a coastal area, we get a lot of bursts of rain. The splashback caused the wood on the bottom to get soaked and transferring it inside. I had some Rubber roof off cuts left so I gave the shed a "skirt". See photo with doors on. I fitted ventilation on both sides, which improved the airflow significantly. On the floor I laid a damp proof sheet and glued it to the side with OB1, then laid OSB on top. Tightly cut and floating. I have opted against insulation as it is just a cutting, routing and making mess shed as I have a small heated workshop in the house. It won't be heated. I have attached some pics.

 

[Jfw2708]

As I just put up a shed on a concrete base...
I put DPM underneath the shed bearers. They come in strips (Screwfix), so easy to cut and lay. I made a mistake with the concrete base being larger than the shed along the sides and as I live in a coastal area, we get a lot of bursts of rain. The splashback caused the wood on the bottom to get soaked and transferring it inside. I had some Rubber roof off cuts left so I gave the shed a "skirt". See photo with doors on. I fitted ventilation on both sides, which improved the airflow significantly. On the floor I laid a damp proof sheet and glued it to the side with OB1, then laid OSB on top. Tightly cut and floating. I have opted against insulation as it is just a cutting, routing and making mess shed as I have a small heated workshop in the house. It won't be heated. I have attached some pics.View attachment 177046View attachment 177047View attachment 177048View attachment 177049

Looks exactly like the shed im getting, perhaps a bit wider. Thanks for the insights, very helpful. As mentioned it will be my only workshop now so will need insulating. Hope you make some good stiff in your shed!

 

[Jfw2708]

Go for 55mm then with a 5mm gap. The t+g will keep most weather out anyway.

Thx James. I’m assuming that’s a typo and its 50mm rock wall with a 5mm gap between the wall and the insulation. Is a vapour barrier over the top of that not needed then?

 

[themack]

Looks exactly like the shed im getting, perhaps a bit wider. Thanks for the insights, very helpful. As mentioned it will be my only workshop now so will need insulating. Hope you make some good stiff in your shed!

Hi Jfw2708, mine is 10x8 . Thanks, I am hoping that it'll get used well.

 

[Jameshow]

Thx James. I’m assuming that’s a typo and its 50mm rock wall with a 5mm gap between the wall and the insulation. Is a vapour barrier over the top of that not needed then?

Sorry 50mm

I'd use polystyrene or kingspan as it won't hold water.

 

[isaac3d2]

1. Do i put a waterproof membrane down between the concrete base and the shed?

You definitely need to separate the wooden shed from the concrete.
@artie makes a good point that membrane could trap water against the runners of your shed.
The way I did this was to lay rows of bricks on the concrete base so that the runners of the shed base can sit on them. I used about 70 bricks for a 12 by 8 shed, if memory serves. Each brick is cemented in place and I put a dollop of cement on top of each brick before laying the base on top (definitely a two man job). Maybe that's overdone but I didn't want any moisture rising in to my shed as I use it as my primary wood store. I keep it dry with a dehumidifier. If you choose this method, beware, getting the bricks level enough in both dimensions is a time consuming (and back breaking) job unless your concrete base is already pretty level and smooth.
Remember one important thing! Get it right from the beginning as correcting faults after your shed is in place is.... not optimal!