Hi, First off, it's natural for the white coat of plaster to have spiderweb cracks all over the surface. These are only in the white coat and are very closely spaced and interconnected. By closely I mean 1/4" apart. _Those_ are nothing to fix or worry about. Cracks that extend into the base coat, and have movement that you can see by pressing, and seem "broken" are something to fix. I like to spray the cracks with bonding agent (garden sprayer) and sponge the stuff in (don't leave any drips of bonding agent; hard to skim over them). It seems to stop any movement for some time. Then add fiberglass mesh tape and the durabond routine, as you have read. The closet area, maybe sand the mess a little smoother to take off any high spots, the prime and then tape. We always use an oil primer around unknown/unforeseeable problem areas, because it really seals anything "bad" like wallpaper glue and prevents problems in the future, and durabond or regular mud sticks to the primer. Regular mud is not optimal for plaster repair in areas where is has to build up thickness; that's where you run into drying cracks (plus it takes lots of time for all the water to evaporate) and when/if it ever gets wet again it falls off lime plaster in sheets. It won't fall off if you oil prime first, and use it sparingly. Use brown coat plaster like Structolite (or Gypsolite), on top of a bonding agent like Link or Plasterweld if down to the lath, use durabond or easysand when the white coat is damaged or missing, use regular mud only for small imperfections and the final touchups, and you'll be fine. Casey

To get access to the defective lath & plaster, you will have to detach the cabinet and move it out of the way. But, before you move the cabinet, you will have to turn off the hot and cold water, and then disconnect the plumbing, as necessary. There should be shut-off valves under the sink. It is possible to remove the soft and cracked plaster, and replace it with fresh plaster. After moving the cabinet back into place, you can put up some new tile, and do a thorough job of sealing the tile and cabinet, so water does not get to the wall. All of this is doable, but it sounds like quite a project. The kitchen sink could be out of commission for a few days...

We all have different methods. Here's my recommendation: Tuck some tar paper (or some other barrier) between the copper and the existing metal lathe if you can. Wrap the tub stub with tar paper, tape it in place. Doesn;t need to be anything purdy or fancy. You want to keep any cement-based product off the copper. Patch in new expanded lathe over the tar paper, you can weave it in to blend the new metal with the old. You'll want to mix two things up; a portland cement slurry, and fat mud. Portland cement bonding slurry. This will act as a bonding agent to help the new mud stick to the existing wall mud. Simply mix portland cement with water to make a thin paste. Brush it on the existing mud to help the new mud stick to the old. Pretty simple. Fat mud. You'll fill that gap with fat mud. "Fat" simply means it has lime in it. Lime make a bit sticky. Recipes vary, but generally, mix by volume 4 parts sand, 1 part portland cement, and 1 part lime. You can buy bags of each individual component at most any box store. Dry mix all the ingredients. Add water carefully. You mix it wetter than deck mud (deck mud is wetted until it's barely moist, it's grainy like beach sand used to build a sand castle) but not as wet as a concrete mix that can flow out when poured on a flat surface. When shaped into a mound, fat mud will hold that shape instead of slumping flat. The goal is to get the fat mud to be wet enough to stick to itself, but dry enough to stick to vertical surfaces and not slump or fall off the wall. If you do youtube seach for "fat mud shower wall" I'm sure there are videos out there. When ready, clean existing surfaces, then paint them with the portland cement slurry. There's no magic here. Just get it on there. Then fill your hole with the fat mud. You can pack it in with a trowel, build it out so the mud patch s slightly proud of the surrounding surface. Then take a stick that's wider than the patch, place it against the good wall below your patch, and use a left/right sawing motion to shave the mud flush with the existing wall.

Are you sure what you removed was plaster and not mortar? In either case, it's not really clear what you want to do. If you want to have the brick exposed and visible then you have a sizable job in front of you replacing the mortar by tuck pointing the joints- after removing any crumbling mortar bit by bit - where it has failed or been removed. This is quite a bit more than a "cosmetic repair". The mortar is what holds the chimney together. If you want to coat the entire surface with something there would seem to have been little point in removing what was already there. You would still need to do some fairly major repair work on the chimney before proceeding as well. Honestly and without wishing to be unduly alarming, the photos show a chimney in dire need of evaluation by a mason or other professional. By chipping off whatever was present, you may have seriously weakened the chimney. The mortar is in very poor condition and I would guess that there are many loose bricks. The expanding foam product shown in the bottom photo provides no strength and is unsuitable for repairing masonry. A coating of some sort and some paint is not going to fix this.