Tile should only be installed on cement plaster on metal lath. If it is horsehair plaster on wood lath tear it out and install a backerboard.

It's impossible to determine if you should demolish the old plaster without looking at the job but usually it is a wise thing to do if you want a good job in the end. Think long and hard about how much you plan to improve the house. The cost of replacing door and window casing trim and baseboards, etc. is the biggest reason to leave the plaster in place.

As far as I know, it is only necessary to tile over cement backer in wet areas like a bathroom. If you are only tiling a backsplash it is unneccessary. I have seen entire commercial tile jobs in food service areas done on drywall.

I totally disagree about removing plaster. plaster is superior to drywall and has a character that you will never achieve with drywall particularly in an old house. I have been in more houses where people went crazy with removing plaster and put up drywall and they totally destroyed any character the house has, they might as well be living in a highrise.

I am doing a complete gut job where we did not save Any plaster but we are combining two small houses and changing the floorplan. If you are keeping the footprint intact and the plaster is not in horrendous condition ... keep it. It is worth the effort.

Keep the plaster as much as you can.
It is a far superior surface to drywall.

You can tile on plaster in a non-wet area like a kitchen, but it will need resurfacing if you every remove the tile.

I would only give up the plaster as a last resort.

Patching with Durabond or Easysand works well.

not to hijack this thread....but 2 of you said that plaster is "far superior" to drywall.....care to explain???

Martin

care to explain???

this will help explain

also it is a better sound proofing material

Here is a link that might be useful: plaster vs drywall

I'm going through the same thing myself. I just bought a 100 year old home that's completely uninsulated (literally going thru 100 gallons of oil a week). Come spring the walls are coming down a room at a time over the summer and the exterior walls will be getting fiberglass batting (I don't care for the blown in only because in my last apartment I started having issues with my bathroom, got permission to redo the tub surround from the landlord, and when I pulled the plaster and lath off the walls, the bays between the studs completely emptied out from the upstairs apartment down into my bathroom).

One thing I will tell you about tiling over plaster, though-- it's highly recommended against in the industry, because plaster tends to suck the moisture right out of the thinset, causing a very poor bond to the tile. If you're going to do this, your best bet is to seal the plaster with a latex additive that would get mixed with your thinset, let it dry, and then set over that. That way, the additive will get a good grip on the plaster, and the tile will get a good bond from the thinset.

Plaster is a much thicker and stiffer material with much better sound qualities.

Sound does not travel as easily through the material resulting in better isolation between rooms.

As the thickness and strength decrease from 3 coat, 2 coat, and finally veneer (basically drywall with 1/8 inch of plaster) the sound attenuation characteristics decrease.

Even the surface is smoother than drywall (if desired).

Plaster wall finishes vary quite a bit by location. Here in the Boston area it is usually no more than 1/2" thick horsehair plaster on wood lath so it is less durable, more prone to cracking, and no better acoustically then drywall. Plaster on metal lath is quite different and usually only found behind bathroom tile. Here we also use veneer plaster on blueboard exclusively so the finish is superior to taped drywall or older plaster. How well the new work integrates with the original trim is entirely a matter of the installer's skill and care. The Irish plasterers in Boston are some of the best in the world and they are slowly being replaced by Brazilians who are also good.