This ceiling didn’t just stain – it rotted from the inside out. Water damage in Buffalo NY is common with our (usually) four full seasons, and then a blizzard or two every year thanks to Lake Erie. We typically stay pretty steady all year round because we are among very few companies locally that specializes in this type of repair. When it comes to this type of damage, water + plaster = bad news.
What Is Efflorescence and Why It Shows Up on Plaster
First signs of a problem is most often a ugly brown ceiling stain, followed by white fluffy powdery substance call efflorescence. Essentially, the lime salts in the plaster, become suspended in the water and are carried to the surface of the plaster in the form of corrosion, bubbling and other ugliness. The longer it remains wet, the worse it gets.
Often what follows the efflorescence is the delamination of the plaster layers. Almost always that involves the finish coat plaster, from pealing off the basecoat. In this case however, the damage remained relatively small, but had the potential to involve the entire wall. It takes a trained eye, to look at water damaged plaster and give a rough estimate as to how big it might get, and even then we are sometimes wrong. Welcome to plaster repair – its the big reason most painters won’t even touch it.
One of the first steps after getting drop cloth runners from the entry door to the work areas, is to turn off the heating and cooling system. What comes next is the dusty and dirty part of the job – the demo, and we dont want to change the air pressure in the house if we can help it, as that change, can cause dust to travel, and we don’t want that. We set up plastic walls, cover furniture, and tape off areas to contain our mess. Then begins the fun part- tearing into these damaged areas with hatchets!
Signs of Plaster Delamination on Ceilings and Walls
The Demo: Hatchets and Dust Control
There is a bit more skill than just mashing an Estwing hatchet into the wall or ceiling. First, the goal is to assess the damage. Is it just the finish coat, or does it include the basecoat and RockLath? In this case it was just the finish coat on the wall, and basecoat and rocklath on the ceiling. This information will dictate the force, angle and pitch of each blow with the hatchet. For the wall damage, we don’t want to make a hole, the base coat was solid, so all we are removing is the finish coat. And while much of it came off with a putty knife, quite a bit had to be surgically chiseled off with the hatchet in order to remove all the efflorescence, since if you don’t remove it all, the chemical reaction that created it, can restart when patching material is applied creating more problems later.
Assessing the Damage: Wall vs. Ceiling
For the ceiling repair, we knew the rocklath was compromised and needed to be replaced due to it sagging. The easiest way to remove this is with an oscillator, but we must first (carefully) bash a hole into the ceiling and check for plumbing and electrical. Once we are in the clear, cut away!
Why We Avoid the reciprocating saw on Old Ceilings: Some people get out the reciprocating saw with a fine tooth blade, but this can destabilize the rest of the ceiling. Especially true if there is a previous patch, and you hit metal lath which is like expanded metal sheets used in tile floors. The blade catches that, and it will brutally jar the ceiling, potentially causing cracks, or worse. Oscillator is much safer, but infinitely louder… ugh our poor ears!
Replacing the RockLath
Once the ceiling is open, we assess the situation and ensure the surrounding ceiling is still tight. After that, while its not “required”, we sister the ceiling joists on either side. This just makes our lives easier, and allows for more flexibility with how we patch this new giant hole in the ceiling. This patch measures 15.5″ X 48″. Why does this matter? because rocklath is 16″ x 48″ so we replaced the entire sheet with new material. Because you can’t buy rocklath in Buffalo anymore, we used a product called Blue Board or Imperial board in place of the rock lath. Then using plaster base coat, floated out the patch. Once that set (the next day), we applied the finish of coat of plaster to complete the repair. Take note, we didn’t “feather out” the patch like you do with drywall, we only replaced what was missing. This makes for a better finished product.
What’s Next: Letting the Patch Cure Before Paint
This patch being a full thickness repair, must now dry for at least 7 days, before we can prime and paint the ceiling. The blue and gold bedroom is ready to go the next day, but instead of making multiple trips, we will wait a week, and then come back and paint everything all at once. Patches will be primed with a dedicated high quality oil base primer, and the walls, ceilings, and trim will get two full coats of paint to complete the job.
To our knowledge, we’re the only painting company in Western New York still performing traditional plaster repair. Most are using drywall compound and calling it plaster.
Update: (9/21/25)
Part II, the finishing, will be posted shortly
As the author of The Carrigan Archives, Dave shares expert insights on home improvement, ceiling restoration, and industry trends. He also personally manages Carrigan Painting’s website and YouTube channel, providing homeowners with valuable resources and a firsthand look at the company’s craftsmanship.
With over 25 years of experience in residential construction, Dave specializes in ceiling repairs and high-end interior painting, often exceeding contractual obligations to ensure the highest level of craftsmanship. His ability to maintain exceptional customer satisfaction in such a demanding field is a testament to his expertise, integrity, and dedication to quality.
For 15 consecutive years, Carrigan Painting has maintained an unprecedented 5-star reputation—an achievement nearly unmatched in the industry.
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