Insulating a garage door is a good way to keep the cold out of the garage. Because most garage doors are made from metal they are extremely good at conducting heat which means that if it is freezing outside the garage will be freezing on the inside unless the garage is heated. Insulating a garage door is not difficult and can be accomplished in a couple of hours. In the project below I had a few off cuts left over and these were just glued over the insulation that had already been glued to the back of the garage door. This garage door is going to be hidden by a stud partition and so no fuss was made when fitting the insulation as it will not be seen. If your garage door will be seen you can spend as long as you like fitting the insulation and ensure it looks perfect!
This is one of the doors in the garage, as you can see it is bare metal and so it transfers the heat from outside very well. Jablite insulation panels were used for this project and are available at most DIY stores. Here we used the 25mm thick jablite panels, although you could use the 50mm thick panels if you wanted to.
This project cost about £45 for two packs of Jablite insulation and two tins of PU adhesive.
This PU adhesive foam was used to bond the insulation to the metal doors, so it is essential that the garage doors are clean and free from dust or grease. Because the doors are vertical it was easiest to cut the panels to size first then squirt some of the foam adhesive to the back of the insulating panel before fixing it in position. To cut the panels to size a hot wire cutter was used, please see here- POLYSTYRENE CUTTING
The foam can also be used as a filler to fill large gaps.
This is the smaller garage door that has been insulated by fixing Jablite panels to the back of it. You could paint the insulation or fix a thin piece of plywood to it if you wanted to, although mechanical fixings would be a good idea. Because of the reinforcing ribs on the back of the door it was necessary to use some smaller pieces of insulation and fix these to the door first so that the insulating sheets fitted flush with the reinforcing ribs.
This is the larger garage door and as you can see not too much care was taken when fitting the insulation as it will not be seen, but this door can still be opened if necessary because the insulation does not prevent the door from opening and is light enough to be lifted up with the door.
