Mountain Lion (PT10) to Yosemite (PT11) Upgrade

If I was to upgrade my current (functional) Mountain Lion/PT10 system to Yosemite/PT11 would I have to uninstall PT10 first?

If so, does that mean completely removing all the folders etc?

I plan on doing a clean install from USB stick.

Sorry if this has been covered, didn't find it in a search.

Thanks.