It could be a good solution for less than perfect walls, but IMO it wouldn't fit a 1928 bungalow (but if you're not trying to do an historic renovation, that wouldn't be an issue). If you go this route, make sure that you really love the look and the color, because it could be very difficult or impossible to change later. I suspect that your contractor suggested this because it'd be faster, cheaper, and require less skill than restoring the walls, rather than for aesthetic reasons. (This is the same reasoning behind popcorn ceilings.) You might want to ask your contractor what it would take to fix the walls instead -- most walls can be repaired. If they can't be repaired, they could be replaced. The cost may not be prohibitive, since a bathroom is a relatively small space.

The glaze does present an adhesion hurdle for the new color. And most of the "paint and primer in one" products do not work as well as a traditional primer. Therefore, I would recommend full priming the surface with a bonding primer and then top coating with a quality finish paint, usually at least two coats. Roll as much of it as you can, with a nap suited for the variations in the texture, probably a 1 inch thick nap. If it's much thinner you may end up fighting with the paint to get in all the crevices.

I did something similar in a place with crazy mixed plasters (some dating back to late 1800's and some from the 30's). We sanded down the highest levels of plaster in the areas that had huge discrepencies in plaster level (yes it's a bit messy, but better than your other options). Then we used venetian plaster for the new wall finishes. That was ten or more years ago when venetian plaster had to be purchased through a high end paint dealer. Now you can buy the stuff by the gallon at home depot and pay for a custom color as well. It's some elbow work to apply, but it will provide a very even finish (you trowel it on and the finish is only limited to the number of layers you're willing to trowel). It's a very old technique, but done in the right colors it's a great modern finish as well. And it's so easy to do. The stuff sticks to just about anything, but if you want to do a test, buy a gallon and practice on a section of your wall. It's VERY important to remember to keep each layer thin as possible. You get cracks when it's too thick, so given the many layers you've got, it may take several layers, but it's not that hard to do. For a more modern finish I'd recommend a pretty wide trowel. Follow instructions, and give it a week to "cure" after you've done at least two, or possibly three coats on your practice section. If you're going to have trouble with it sticking to the old finish you'll see it right away. I personally would pop down a layer of primer before I did anything else, just to seal in anything that might be on those dirty walls :) The plaster finish is hard to get through, but sometimes "stuff" from the old days tries really hard and makes it :) So to be safe, seal it all in and then go for the venetian finish. I highly recommend using a paste wax finish verses the sealer that they sell in the stores. It's basically the same thing, at 1/3 or less the cost, and it's richer. I am picturing a light, silvery or soft green color for some reason, and if you do go light, use a clear paste wax. If you want rich and dark (think chocolate or ebony) then seal the finish with a dark paste wax.

Hi, Joni, I’ve been researching Venetian plaster for an upcoming project. Behr has an acrylic Venetian plaster (about $35 a Gallon) you can special order. That’s what I’m using, it’s a really nice product.I believe Modern Masters is an acrylic product as well. First of all- there is NO 1-step process for a quality finish. If you have orange peel, you have even more layers (steps) to do because after you prime your walls, you will need at least 1 or two layers of skim coat to smooth out the orange peel texture. Venetian plaster is Usually applied to smooth walls over a primer, then 2 or 3 coats of plaster, the plaster has to be burnished (polished) with the trowel and then sealed with a topcoat of wax or sealer to protect the finish from fingerprints etc. you can apply a wax sealer that has metallic or pearlescent qualities over the Venetian plaster to give it luster and shine. This is a fairly labor-intensive process, that’s why it’s so expensive and usually only seen in higher-end homes, unless you have the time and know-how to do it yourself. Look up Venetian plaster on You-tube and decide if it’s something you want to take on. It’s a very cool product, but you may just want to do an accent wall. Let me know if you have any other questions- I am working on some sample boards I’m doing for my fireplace chase project. Here’s a pic of one with 3 layers of plaster over a piece of drywall that I skim-coated smooth, then primed. The darker areas have wax on them, the dark corner has colored wax on it- I’m experimenting before I do my project, and you should too, Good Luck!