Most of what is being sorted through are old props and building materials that have been shoved into holes or under the stage, anywhere they can fit.
Perhaps the most interesting thing found during the clean-up of the Ridgway St building is a set of old doors.
"We pulled them out and we're definitely not throwing them away because we're looking at them thinking they might be the original doors of the building," Portland said.
"The outside of the theatre has changed over the years, it was a library before it was the theatre, it's over 100 years old. Hopefully we can do the doors up and use them for something at some point."
Portland said the young performers getting involved in the clean-up made him proud.
"Young Reuben, we've watched him grow up, he has come through the theatre ranks and he is going to be on stage in this next performance.
"We call ourselves the theatre family, it really does have that feel and it makes me really proud to know that as a theatre community, we have done enough to get these young people giving back."
The building has been a theatre since 1933 and Portland said that like many older buildings it has some issues.
"We are the caretakers of the theatre, so really it's our duty to make sure we're keeping the place clean and tidy.
"We need to sort out some issues and we are in the process of raising funds to upgrade and keep ourselves current."
Ringing Changes will run on July 5, 6, 7, 12, 13 and 14 in the Wanganui Repertory Theatre.