Well, since you are using Roof macro it is a little bit tricky to elaborate but:
Roof macro has a submacro in the style which uses X, Y, Z size to calculate angles, overlapping etc.. especially important is Y size (thickness) that has a major effect on the whole style.
So, the easiest workaround for just scaling tiles is to add transform node and scale only X/Z size.
Set the parameter value 100+scale% since the default 100% will be 1:1
Not an ideal solution but just an idea...