The message
from "Roy Lynch" contains these words:

I have had 3 tonne delivered and it is about 3 months old. Its currently
sitting at the end of my garden till autumn so I can put it on my newly cut
out borders. My question is.. would it be better to cover it up from now
till autumn with some tarpaulin, would this help the rotting process a
little faster or better to just leave it in the open air?

Covering the top (letting air in at the sides) will stop rain leaching
out the nutrients, and keep it warmer which helps decomposition.

Lucky you :-)

Janet