How to thermally insulate and sound-deaden garage?

Callum_W

Hello!

I'm looking for a suggestion on the correct materials for insulating the roof of my garage. Currently it gets very cold in winter and very hot radiative heat in summer, so I'm looking to make the space more pleasant year round.

Ideally, I'm looking for a cheaper option which will thermally insulate, and sound deaden the space. Some considerations I've noted are:
- In winter, the sheet roof has lots of condensation.
- There's a bit of electrical wiring around the roof beams, so the option should be electrically safe.
- Would be nice if I could not leave the insulation fully exposed, what options do I have to underlay something like fabric underneath the insulation to leave a more welcoming appearance. If there aren't really any cheap options, then exposed it is.
- Online I'm seeing various contradictory things about breathing in fibres from exposed batts and such. Some say it's totally fine after install, some say not. I'm asthmatic, so just looking for confirmation, I understand modern insulation is a lot better than it used to be.

- I will be putting some blackout blinds on the windows, but I'm struggling to think of a way to better insulate the roller door. What options do I have?

Here are some photos of the space:

EricL

Hello @Callum_W 

Welcome to the Bunnings Workshop community. It's sensational to have you join us and thanks for sharing your question about insulating your garage.

I propose a two-step approach that will provide you with long term temperature stability in your garage. First, I suggest installing a Bastion 300mm Aluminium Mill Roof Vent or equivalent in the centre of your garage roof. This will help with ventilation by keeping the air moving and will lessen condensation.

Second, I recommend building a lightweight timber ceiling frame that will hold the insulation bats in place. This will provide excellent insulation and protect the room from radiant heat from the galvanized roof and at the same time retain the heat in the room from escaping through the roof. 

The ceiling frame can be covered with light weight timber such as 2440 x 1220mm 3mm Plywood Pine Premium BC Grade or similar. you'll need an electrician to move the lights down onto the ceiling surface.

In regards to your garage roller door, I propose thinking about closing it permanently and building an insulated timber wall or you can build a mobile insulated panel that you can place in front of the roller door to diffuse the heat. 

Here is a link to our best advice: How do you add insulation to a garage or shed?

I also suggest having a look at these discussions - How to add insulation to metal garage roof? by @RKN00b and How to insulate garage ceiling? by @Nancy12. There are some excellent suggestions on how to insulate a metal roof.

If you need further assistance, please let us know.

Eric