Internal lining and insulation to timber outbuilding

[amthorpe2000]

We have an outbuilding that was an open timber garage under a tiled roof, have had doors put on to add security so it can be part workshop or games room. the construction is as shown in the image. We are thinking of adding an internal skin where the pink is and want to do it as cheaply as possible but keep it functional, and paint it to help it to reflect light.

What should we put on the inside?

12.5mm Plasterboard £ 5.76 per m²
11mm OSB £ 9.93 per m²
9mm OSB + 9.5mm Plasterboard £ 13.02 per m²
18mm OSB £ 14.44 per m²
11mm OSB + 9.5mm Plasterboard £ 15.24 per m²

Wondering about insulation as well, its not heated so not too worried about heatloss, but would like to keep the chill off and reduce condensation. wondering whether a 25mm pir board just behind the pink or a cheap foil roll insulation behind the pink would be worth it.

TIA

 

[Wayners]

Plasterboard may get damp and mould. Better off with osb wood.

Foam insulation has foil so room becomes air tight so condensation can be a problem. Rockwool don't trap moisture.

I had rockwool and osb board on my walls and foam insulation sheets in the ceiling.
Mice love the rockwool though

 

[freddiemercurystwin]

Forget foil insulation's, they need an air gap on both sides to work properly, so the cheapest would be 25mmPIR + 9mm OSB, assuming you're not going to be fixing much to the walls. but note that unless the internal space is heated the insulation will do next to nothing.

 

[amthorpe2000]

Forget foil insulation's, they need an air gap on both sides to work properly, so the cheapest would be 25mmPIR + 9mm OSB, assuming you're not going to be fixing much to the walls. but note that unless the internal space is heated the insulation will do next to nothing.

Thanks as it wont be heated except by bodies. Will probably go with 11mm osb. Just thought the insulation might keep the cold out a bit, just to take the chill off

 

[amthorpe2000]

Plasterboard may get damp and mould. Better off with osb wood.

Foam insulation has foil so room becomes air tight so condensation can be a problem. Rockwool don't trap moisture.

I had rockwool and osb board on my walls and foam insulation sheets in the ceiling.
Mice love the rockwool though

Hadn't thought about mice liking rockwool. Hadn't thought about the plasterboard getting mouldy. Will probably just use 11mm osb. Had only thought about plasterboard as it would reflect light better.

 

[freddiemercurystwin]

Paint your OSB white.

 

[amthorpe2000]

Paint your OSB white.

Yes. That is what I will do, didn't want to waste money on the expensive primer apparently necessary when painting osb to stop it being yellowed by the glue

 

[Wayners]

I painted mine but I can't remember if I used a primer. Don't think I did. Just use any emulsion