garage insulation

[caseyjones1961]

looking to start insulating my self built timber garage...frame is mostly 2x4's,sheathed with osb and will have a 12mm internal lining
was going to use 100mm kingspan or the like....til I saw the price Can anyone suggest a more suitable(read "cheaper") alternative?....I've got the chance of some cheapish leftover cellotex batts but they are only 75mm...could I get away with using them or would the additional 25mm airspace cause any issues particularly regarding the dreaded condensation?

 

[foxhole]

I used rockwool fairly cheap, keep eye open for skips, excess often thrown away, got 4 rolls via freecycle last week.

 

[ntb]

What you use for insulation depends on what you are trying to achieve. Why are you insulating it and what are you going to do in there?

 

[caseyjones1961]

Thanks for the replies...mostly it's to keep the place at a pretty even temperature to store my tools,motorbike etc and work in over the winter.
Will be putting in some soffit vents and basic form of heating but obviously it won't need insulating to standard of a habitable building.

 

[ntb]

Ok. Then I would say 50mm of well fitted polystyrene on the walls and 100 mm for the roof would be perfectly up to the job. Your biggest issue then would be draughts from the doors.

That said, if you are going to be welding in there then rockwool would be a safer option - or boarding over the polystyrene.