[Gpa113]

Hi Rob,

You are very welcome 

Polycarbonate roofing sheets are perfect for this job, so grab them if you can!

If you think of anything else that would help,  or need further clarification,  just reply or message me. 

Pip

[Scuderia_Turini]

Hello Rob, 
Pip mentioned insulation and that is worth doing. Unless your garage is heated it will get very cold in winter and warm in summer so expansion and contraction can be issue with Sport track. If you have watched the James May video of Brooklands Scalextric track you will  see what can happen.
If your garage is damp then corrosion of the rails will be likely.

Leo