Replacing the factory-supplied light gauge D'Addario EXP strings with medium gauge strings adds additional tension to the neck. Thicker strings will change the playing characteristics of the instrument. The nut slots will almost certainly need to be filed wider - especially on the base side - in order to allow the strings to sit as low as the light gauge ones. The truss rod may need adjusting in order to remove extra relief caused by the pull of the heavier strings.
Although the guitar should suffer no ill effects you should keep a close eye on the neck and bridge. There is a slight possibility under certain humidity conditions that you will experience a lifting of the top wood behind the bridge.
We do not recommend heavy gauge strings for Tofino, Dionisio, Nanaimo or the Ian Tyson Limited Edition
The Tom Rush Signature Edition and the Tom Rush Naked Lady have a thicker neck and can handle the tension of both medium and heavy gauge strings.