You want to install a foil blanket on your roof especially if you're planning on fitting a concrete tile roof system on your house. What's great about the concrete roof system is that it has air space underneath the tiles as it's using a batten system i.e. it using a 1×2 wood strip to mount the shingles onto, you're going to have the required air space so you can put a foil blanket on top of the roof below the tiles.
Now, this also works on standing seam metal roofs or a coated metal shingle roof. Any roofing system allowing that air space you can put your foil blanket on top of the roof. So, from top-down, you're going to have tile, you're going to have airspace, then there's going to be the foil, and then you'll have your waterproofing layer and finally the deck. This is by far the best system to keep out radiant heat. The house will stay considerably cool, the customer saves a great amount of money on their energy bill.
This allows a lot of energy savings by repealing the heat before it ever even gets in the structure. Plus, it's easy to install, all you got to do is roll the foil blanket on top of the waterproofing layer before the battens. Now to explain how the foil blanket insulation helps increase efficiency and comfort. So, the tile concrete roof can easily reach up to 150° on a hot sunny day. The decking behind it can reach up to 140° because the heat is radiated across space and is being absorbed by the roof and ultimately travels into the home. By installing the foil blanket on top of the membrane with the required airspace, the tile's still going to get hot, but instead of radiating it will be reflecting.