Steel or aluminum walls are very good at blocking wireless signals.
How to boost cell signal in house with metal roof.
With external antenna elevated a minimum of two feet from the metal roof you can be sure the reception will be captured and boosted.
Even if you have a perfect signal outdoors you might get little or no cellular coverage indoors.
In a nutshell metal roof or not the type of building material is irrelevant the cell phone signal will be injected into the internal space via a special high quality cable.
These systems can boost the signal indoors for one or several cell phones.
What causes bad cell phone reception at your house.
Use a wireless repeater to strengthen the wireless signal as you go through your home.
Metal buildings offer a challenge for cellular signals.
An electronics store should be able to sell you a cell phone signal booster and an external antenna.
The easiest way to improve the cell phone signal inside a metal building is to use a building cellular signal booster system.
If your home has energy efficient windows a metal roof or siding or is made from concrete or brick these materials can all block signal.
Adding a cell phone signal booster in your house would have been helpful before the metal roof and certainly would be helpful after your metal roof is installed.
However if you have good to excellent cell phone reception now the metal roof should not have any noticeable effect.
See more on metal roofing here.
The cables should come with the power booster.
This is the most effective method of treating the problem.