They might refer to themselves as joiners as opposed to carpenters but in reality many do a bit of both in the traditional sense of the words. A starting point for you would be to speak with two or three local joiners, advise what you require and they'll be able to advise if it's a job they can do in its entirety, quoting you accordingly if they can. The job should be within most of their skillsets, however you won't know until you speak with them. And make sure you're engaging with reputable tradespeopleSo do I need a carpenter or joiner to do this. Do you think they will be comfortable cutting sand/cement back and installing a frame