Walls and Ceilings - What to do for new ceilings

Hi there, we are renovating our 25 year old home and want to replace the Knotty Pine ceiling in the Kitchen with a Rhinoboard (Gypsum) Ceiling. It will be nice to make it seemless but we do not know how to do it. The metal strip idea looks good for only a couple of years and we want it to look good for a long time. We dont want to remove the existing ceiling as it helps with isolation, can we fix the new ceiling boards directly onto the current knotty pine?

Couldn't you just screw drywall on the existing ceiling?

I just looked up "rhinoboard". It is an underlayment for tile floors. I don't think its made of gypsum. why do you want to put this on your ceiling?

Rhinoboard is the name of our gypsum type ceiling boards in SA. It is basically two layers of paper with gypsum in between, it is standardly used in houses as ceilings with a aluminium strip that holds them together. We were thinking of just screwing the new boards onto the existing knotty pine. But we need to know what to do with the seams between the boards. A gentlemen at our building supply shop suggested a type of tape that you stick onto the two boards and then cover with a sort of filling, then sand down, and paint. Does this sound more or less like the thing to do?

It does, but the fact that you're asking such basic questions makes me think you should hire this done. It's not overly difficult, but you clearly have no experience.