Question #1: If I go with a formica backsplash, drywall is not reccommended as a backer. From what I have read it should be particle board or MDF. My concern is that drywall is needed for it's fire rating. So do I need drywall first and then the particle board or MDF and then the formica?
Question #2: If I go with tile instead, is cement board a better choice than drywall as a backer? The cottage is not used or heated in the winter. Glad to hear some thoughts about this. Thanks, Ron
#1 - While I wouldn't put laminate over sheetrock for a working surface, it's been used many times and in many places for backsplashes over drywall. Liquid Nails gives you a decent working time. I'd spread with an 1/8" notched trowel. Vertical joints are the tough part - best if you can just bury them in the corners.
#2 - I'd use some kind of isolation membrane between the tile and the substrate - I've used both Redgard and Kerdi Ditra with excellent results. Not sure where you're located, but this could be beneficial if there will be large temperature swings for this installation.
The kitchen in this home when we first bought it had (orange) Formica (or similar) on the entire backsplashes and it was applied over drywall. It did come down easy when we demolished things. But here's the thing...you can do the drywall and use something like .25" MDF or HDF as your direct substrate for the laminate. That, in turn, can be adhered to the drywall with appropriate construction adhesive. So you get your fire benefit while using the best surface for the laminate and not adding a lot of thickness to the wall...the same or less than putting up tile.
My subway tile went right on the drywall with mastic.
My house has laminte for the backsplash adhered directly to the drywall. I've had no issues in 18 years so far. The laminate runs up behind the upper cabinets so it looks like a full granite backsplash (the laminate looks like black granite).
I have installed laminate straight to drywall before, used silicone caulking to fasten it. Cut it long and push the countertop and top cabinets back against it.
Ron