Lining a workshop/craft room

[Myfordman]

Ah, misread it Myfordman, apologies. Breather on cold side, and taped Celotex forms the vapour barrier on the inside, then ply.

Got it, thanks.

If the taping is perfect then absolutely fine but for what little extra it costs, I like to staple on a layer of polythene to be super sure.

 

[artie]

I'm getting the hardwood ply at £28 a sheet.

That's a fantastic price for hardwood ply. Is it of Chinese origin.

I've been asked almost that for 11mm osb.

 

[2sheds]

They do a Chinese ply at £25.20 a sheet. 11mm OSB is £29.
Sheet Materials - High Strength Sheets for All Your Projects – Cut Price Insulation
Delivery cost might screw it though, I got 16 sheets so it was worth it.

 

[keithy1959]

It's important to remember that OSB was designed to be used underneath another covering the reason being it is formed with formaldehyde and other toxins which are carcinogenic. If they are not encapsulated and someone uses a heater in there for instance they will breath in tiny particles over time- they could die early! In fact many anthropologists are now studying many materials used in construction and say we are surrounding ourselves in our homes with some very nasty components that no-one wants to mention too much. Keep you and yours safe and dont be a sheep is my advice, find natural material to use as much as you can perhaps.

Is this realy still the case ? I remember the Guardian doing a thing a few years ago about formaldehyde in man made boards, which , IIRC was largely based on old standards and journalistic hype. I thought the E1 standard which seems to cover most OSB I've seen on sale has locked this right down ?

 

[plum60]

Is this realy still the case ? I remember the Guardian doing a thing a few years ago about formaldehyde in man made boards, which , IIRC was largely based on old standards and journalistic hype. I thought the E1 standard which seems to cover most OSB I've seen on sale has locked this right down ?

I cant say for sure so won't say but I do think there are producers that will not lay claim to eventual claims given their warnings so best to stick to those at least. I think if you used heat in a say a smaller room with osb on show there would be an issue anyway coated or not. It was designed to be used underneath another covering remember so they would always say it was miss-used if it was not encapsulated somehow. Asbestos is safe unless you cut it so would osb be the same- would you allow exposure of stuff if you cut a chunk out for socket access for instance. I think any source of heating in a room with osb would be a no if it were my life I was thinking about. I don't think it's fake science. You should probably not depend on producers to be directly honest given they have huge investment in selling vast quantities.

 

[plum60]

I cant say for sure so won't say but I do think there are producers that will not lay claim to eventual claims given their warnings so best to stick to those at least. I think if you used heat in a say a smaller room with osb on show there would be an issue anyway coated or not. It was designed to be used underneath another covering remember so they would always say it was miss-used if it was not encapsulated somehow. Asbestos is safe unless you cut it so would osb be the same- would you allow exposure of stuff if you cut a chunk out for socket access for instance. I think any source of heating in a room with osb would be a no if it were my life I was thinking about. I don't think it's fake science. You should probably not depend on producers to be directly honest given they have huge investmegistsnt in selling vast quantities.

Also I do know that every year at the annual anthropologists gathering there are papers being read on construction materials... like osb and toxins. When experts give their papers on this subject the rooms are full to overflowing, there is a huge amount of interest and research on the subject that is showing that we are being surrounded with toxins in our homes. There are numerous case studies being conducted in various parts of the world to support to demonstrate health issues linked to toxins in commonly used materials.

 

[Glitch]

I thought you put the breather membrane on the cold side of the insulation, i.e. put it on first? That's what I am about to do with my shed/workshop. Then I'm using 50mm Celotex and 12mm ply over the top. Ply is slightly cheaper than OSB at the moment. I'm getting the hardwood ply at £28 a sheet. 18mm is £38.50. Cutpriceinsulation.co.uk

Breather on the cold side, barrier on the warm side. Both are aimed at keeping water vapour out of the insulation which could in time render is useless depending on type.

That's right for timber sheds.
The OP said the garage is built into a hillside and has been tanked. Need more information about the wall and roof construction.
Tanked walls are meant to be a vapour barrier.