Mending Outside Corners in Plastered Walls

plastering is an acquired skill.

There is a square bay in the dining room and the outside corners -- those that thrust into the room -- are cracked vertically from floor to ceiling.

wet sponge each layer smooth.

ehBeth wrote:

Rockhead wrote:

plastering is an acquired skill.

quite wonderfully, plastering and making dental plates and preparing cake batter have a lot of similarities - once you've got the texture right you've done the most difficult part

POM is a phenomenal baker - with the right advice she could probably make a good go of repairing plaster

Don't mess with plaster to repair plaster...Plaster cannot be sanded, so it has to go on right the first time... Skaroo that... Just by some topping and blast in in... But if you do not resolve the structural issues it will crack again...

Quote:

There is a square bay in the dining room and the outside corners -- those that thrust into the room -- are cracked vertically from floor to ceiling.

First you have determine if those portions that thrust in the DR are load bearing and if they are, has the load been, is the load being transferred adequately to ground.

[Is there any cracking in other locations that are close?]

This is a faaaairly simple task. Look to see what is under the end points of those extensions, or if there is a continuous bearing wall under the whole section.

You could of course just fill those cracks, but they may open up again if there is loading. Are the corners square or rounded?

Get a tile scriber which is a little tool that has a carbide tip. Use it to scratch the cracks and open them up and IMPORTANT, remove all loose plaster.

NEVER TRY TO GLUE LOOSE PLASTER BACK IN PLACE UNLESS IT'S A DETAILED PIECE WHICH IS, OF COURSE, A DIFFERENT BALLGAME

You can then use drywall mud and if the cracks are now wide, use it in conjunction with drywalling paper tape.

The trick to getting a smooth surface is to do repeated fillings, with as broad a knife/blade/trowel as is possible. Don't worry that there are deep recesses in the first coat. You could use a fast set drywall mud for the first coat but make sure that with this coat [all coats actually] you skim the excess off.

Never leave bumps or lumps. It's easier and way less messy to add later than remove.

There should never be any need to sand until after the final thin layer of mud is done. This final layer should be a thin skim coat to fill tiny holes and recesses.

Don't sand, wet sponge each layer smooth.

I saw the This Old House guys mend a crack using metal buttons that are driven into the wall with an electric drill. I have an electric drill but am timid about using it.

This is the same country (US) that continues to claim that we are careful about collateral damage.

You should have seen the frustration on the face of the paper hanger

I am not certain what a deep or wide crack is.

Someone told me that patching, then priming, will reveal more flaws and is a good way to proceed.

I had an ex-husband who took out the wet plaster . . . actually horsehair plaster . . . from a 1920s house and replaced it with drywall. No thanks. My income is too small to support that sort of replacement, which I would have done with the ceiling in the living room: small areas of plaster crisscrossed with lathing. It looks like an attic. I painted the ceiling lavender rather than leaving it white which helped.

I am dizzy from reading these responses. Have to work for a few hours at the liquor store than off to a faculty orientation, so there is not a minute to spare today.

I spent a long time patching the walls of this room with joint compound. The room has a fireplace opposite the bay that protrudes into the room and one of the short walls is angled with a glass door in it, keeping drafts from the hall out. This is really a beautiful room.

The former owner's son was a skin diver by profession who helped his mom a lot with home repairs. Generally, he didn't know what he was doing: he is responsible for at least one wall in the first floor bath varying a half inch from top to bottom. You should have seen the frustration on the face of the paper hanger (I knew I would be sitting on the floor, crying, if I even attempted it. It was worse than I thought.) I hired to do this tiny room. But, having a son who is helpful is nothing to criticize. I just wish he had taken more care: he didn't sand the patches in the upstairs hall.

I am not certain what a deep or wide crack is.

The wet sponge idea sounds terrific!

Someone told me that patching, then priming, will reveal more flaws and is a good way to proceed. That is what I did. The walls are not perfect but better. I think that one wall was replaced/repaired by a pro. It is absolutely smooth.

This is an eccentric house, which is why I love it. There are seven walls in the living room. If you discount the bay and the thrust fireplace, there are five walls in the dining room!