If you read my post a week or so ago you will know about my fight for the cracked ceiling in the sunroom and living room. Everyone is an "expert" and wants you to do it their way. Contract it out to a pro, use a special formula, drywall it, etc. After a lot of research I decided to make things interesting and do it myself and create my own special formula. I knew the key was to stabilize the plaster that was loose to the wood lathe behind it. I also knew it was important to clear the crack out, like cleaning out a cut on your body, to ensure the loose plaster doesn't prevent your new plaster from adhering. In some cases, it would mean opening it up a little wider, initially making the roof look even worse. Here is my process which I think is great if you want to save money, do it yourself, and while you'll have a few areas that aren't perfect, hey, it's an 80 year old home! Keep your plaster ceiling, don't drywall it. Even if the cracks come back over time the way I figured it over 80 years only this many appeared, I'll let someone else worry about fixing my work in 80 years :)
1. Roll painters paper over the entire floor and tape it down
2. Seal off any exterior entrances to rooms with tarp
3. Take your scraper and scrape the excess paint from all areas of the ceiling that it is peeling/chipping from. If you don't, you WILL notice this when you paint over it
4. Use your scraper to open up the cracks. Put it inside the crack and pull it the length of the crack. Get all the loose stuff out and it will wider a big but don't worry. Try not to make any areas chip away from the edges. Click Here - Read More
5. I bought acrylic bonding liquid that I would mix with my plaster. The description said "assures adhesion to previously painted surfaces, floors, and nonporous surfaces. Prevents separations, cracking, and increases flexural strength. For use with cement or plaster-based mixes on both exterior and interior projects." I literally took a Dunkin Donuts plastic cup, cut the top off, threw a bit of plaster in, poured some of this bonding agent in, mixed with my finger (wearing thick protective gloves) and once it seemed like it was mixed well I would inject this into the cracks using any method I could. In most cases, putting it on my finger and shoving it up.
6. Once all the cracks have this inside let it dry. It took about 6 hours for me.
7. Next, take the plaster and plaster over the cracks, thining it as you get to the edges, like applying mud to drywall.
8. Let it dry and away you go sanding.
9. Once sanded I had to apply more plaster, let it set, and sand again
10. Next, it was totally smooth, dust was everywhere, and it was ready for primer.
11. I bought a 5 gallon bucket of Kilz for heavy stains, odors, etc. The first coat seemed like the old plaster ceiling absorbed it. I liked to think the ceiling was thirsty :)
12. I let it dry and added another layer
Soon, I had a finished product:
It was this
Now this
An area view:
At the end of the day it looks much improved. A few areas you can see a slight imperfection but it is an 80 year old home. I'm hoping the cracks don't reappear anytime soon but I am prepared for a few to open back up as the house moves during various temperature changes, etc. I'll let you know how it holds up.
Total time on the project was 2 full days.
The rooms were a complete mess and you must have them empty and sealed off.
Make sure when you sand your plaster down you have a nice hand sander. I used 80 grit and 120 grit paper. First pass was 80, second 120.