Garage ceiling and insulation

[malcster1975]

Hi all not posted in a while so apologies

Moved into a new build with a separate garage
Wife has a heat pump dryer we plan on using.in the garage but it's cold in the winter so will run a small heater when it's in use

I have placed a rubber floor over the concrete and boarded the walls with insulation the 9mm ply as well as insulated the garage door

Onto the roof and there is a big void above so plan on boarding this with 4mm ply painted white attached to the underside of the joists 88x38 mainly
Should I put space blanket on top of the joists or cut insulation and lay it in between the joists

Just concerned that once it's boarded I won't be able to see the joists anymore so don't want to lock moisture between insulation and timber joists

Picture of roof before the walls were boarded

 

[Mottie]

Wife has a heat pump dryer we plan on using.in the garage but it's cold in the winter so will run a small heater when it's in use

I found out the hard way that heat pump dryers don’t work in cold outbuildings. I ended up giving it away and just getting a basic one - it’s only ever used to dry towels or jeans in wet/cold weather anyway. I thought the advantage of a heat pump dryer was that they used less power than a standard one. Surely that advantage is negated if you've got to run a heater when it’s in use?

 

[malcster1975]

I found out the hard way that heat pump dryers don’t work in cold outbuildings. I ended up giving it away and just getting a basic one - it’s only ever used to dry towels or jeans in wet/cold weather anyway. I thought the advantage of a heat pump dryer was that they used less power than a standard one. Surely that advantage is negated if you've got to run a heater when it’s in use?

Also want to try and warm it up for general use if I need to get away from the wife

 

[Wayners]

Vent the space above to get air blowing through.
Kingspan between joists
Stick 25mm kingspan to 8x4 plasterboard (cheaper than buying) and hire board lifter for a day and fit over entire ceiling. Moisture cant get past the foil on kingspan.
Tape joints
Paint ceiling.
Buy a dehumidifier ( game changer) to dry laundry and also control house condensation or buy the cheapest vented tumble dryer you can find and vent it out the house.