Insulate your garage ceiling and walls
The most efficient thing to do to reduce the heat in your garage is to seal it and prevent from the heat outside. A good insulation makes a garage for 20-30 degrees cooler than the temperature outside. Insulation can not only reduce the heat in hot seasons, but it can also keep it in your shed when it is cold outside.
You can start insulating your garage in the upper side of the roof by filling all the gaps with spray foam, which will be pretty economical on your heating and cooling bills. If you have a garage without the ceiling, then it would be quite a good thing to acquire it, thus providing your garage with extra heat barrier.
To insulate the ceiling and walls in your garage as much as possible, use a composition of rolled insulation and drywall or sheetrock. You can do it by connecting the rolled insulation between the ceiling rafters and the 2x4s in the walls and then overspreading with drywall or sheetrock. If you have not such a possibility to insulate the whole garage at the moment, insulate the ceiling first as the sun rays are falling on straight on it and it is the hottest part of the garage. When the ceiling and the walls in your garage are insulated, make sure all the windows and doors are sealed.
Insulate your garage doors
Garage doors are rarely insulated, but taking to account their wide spacing across your home, a non-isolated door can shorten you in the heat seal your home has around its doors and windows. This means that the heat can enter your home through its large gaps.
What concerns the flooring in your garage shed, a good option is the concrete floor, as it absorbs both heat and cold. So, if your garage is insulated, the concrete floor provides the possibility to keep cool in summer and heat in winter.
As a garage door is the largest admission of the heat to your garage floor, it’s worth insulating it, if possible.
Ventilate your garage
After you complete with sealing, insulating and sheetrocking, you should come up to ventilating of your garage shed. As heat rises, you can use the option of venting your garage from its top, but it may lead to leaking while rainstorms in case of vents not to be properly sealed, or you can choose the option of venting it out of the wall.
Ventilation can be provided through different vent designs. You can even set an exhaust fan on the roof which will draw hot air from the garage or loft. You can even acquire the one that is controlled by a thermostat.
When installing a fan, provide it with a backdraft damper to avert hot air coming. You can also experiment with ceiling fans to help the air moving.
Extra things to remember
Your home and garage colour plays a big role in adjusting the temperature inside. Choose lighter colours for the roofs, exterior walls and garage doors to reduce the heat inside while darker colours absorb it.
The aim is to prevent the sunlight to enter your garage shed during the day, so you can provide the windows with some shades.