I have a 6m x 6m x 2.5 mtr high double free standing garage insulated in the walls and roof with 100mm fiberwool. Insulated roller door. The floor is bone dry laid in 2002 with a DPC.
Enlarged in 2013 with a new section 6m x 6.4m x 4mtr high extension, roof and wall insulated with 150mm fiberwool.
While it does not feel damp during the winter, instruction manuals for stuff will not stay flat and the spanners on the peg board show some minor rust after 6 years.
Even with that insulation and good DPC it is left at times for a few weeks without being heated therefore water will come out the air on a dampish day, end of story!
While Peter advises his garage gets some minor heat from other rooms as it is part of his house, it will be bone dry.
On a cold damp day unless there is some heat in a garage a small amount of dampness will be there.
Due to the insulation on a day with -2 C outside it is at a nice working temperature within say 40 minutes.
