Hello Everyone, I'm new to the DIY Forum. I've read some good advice for other projects/repairs on here in the past and figured I would give it a go for some bathroom ceiling repair advice. First and foremost I a had leak in my roof that caused the ceiling to begin flaking. I have since repaired the leak in the roof and are now ready to attempt the ceiling. My home was built in 1959 and has the old plaster/wire mesh walls. As far as the ceiling goes, I have no idea what it is. It looks like cement..I thought possibly it was a cement backer board, not sure to be honest. To make a long story short...What do you guys think the best approach is to rectify this? Should I attempt to patch/repair it or tear it down and install drywall? Below are pics..Thanks in advance for all of your time and advice.

Regards,
Matt

 

Welcome to the forums Matt!

The brown 'concrete' is the plaster base coat. While our plaster pro can tell you the correct method to repair plaster what I've always done is to use a setting compound like durabond [instead of plaster] to make the repairs. Basically you scrape off all the loose and then apply the durabond. Durabond can be a bear to sand so it pays to apply it neatly. If that's an issue, you could use regular joint compound for the final coat - it doesn't dry as hard but it's easy to sand.

Once the repair is done; sand and remove the dust, prime and then paint with a latex enamel - a bath rm enamel would be even better.

 

One other option is to knock the remaining loose pieces off, use Durabond or joint compound to fill the missing area - being sure not to fill it higher anywhere - and then hang and finish new drywall over everything.

Just an idea. With a patch this small, a finished ceiling area that looks this good, and a scratch coat that looks as even and solid as yours does, I would definitely try my hand at repairing the finish coat.

One tip: Use a spray bottle to thoroughly wet the scratch coat before applying the finish coat. That will keep the mating surface damp long enough for the new finish coat to cure and bond to the scratch coat.

 

Guys, thanks so much for your advice..I really appreciate it!

 

Were I to do it with a setting joint compound I would first scrape off all the rest that is loose. Maybe you will end up taking off the whole finish coat on the ceiling. In a way that would be the best. Then you could put up new drywall and tape and finish it or you could skim the brown coat with the setting joint compound. Durabond is the hardest and maybe the best. It must be laid down perfectly for you do not want to try to sand it.
Now if you end up filling in the area after you scrape off the loose lay in the Durabond or other setting joint compound like EasySand also by USG -- there are other brands -- in thin layers and do not build it up over the remaining finished work. Keep the old work clean. Just as the material begins to set use a spray bottle of water to spray it down to lubricate your trowel and trowel it through its set. If it is still low and needs another coat then as soon as the first coat is set you can give it another coat. I would not have to sand it but you might. And the suggestion above to use regular joint mud as the last coat since it sands easily is a good one.

One more thing. Give that stained area a coat of Kilz or other oil stain blocker before you start and maybe it will not bleed through. Then if it does bleed through give it another coat after you finish before you prime and paint..
Almost took longer to tell you how than it would to do it using 5 minute mud.

I think you have gypsum plaster over gypsum lath like RockLath by USG or equal. This is a very good system. If you do indeed have gypsum plaster over expanded metal lath you have the best of the best. Think long and hard before taking it off and substituting drywall.

Since this is a bathroom the finish is probably Keene's cement. It can lose its bond but it is the best interior plaster finish there is or was in the era of your house.