I have accepted the fact that MDL does not have a built in "floating at bottom right" FAB button (similar to the Android SDK).
However, I have stumbled upon another issue. There is no built-in way to make a regular button bigger. Be it a fab one or a regular one. Ideas?
Here's what I use currently:
<button class="mdl-button display-4 mdl-js-button mdl-button--fab mdl-button--colored"
style="margin-bottom: 50px; margin-right: 80px; bottom: 0; right: 0; position: fixed;">
<i class="material-icons">add</i>
</button>