Hairline crack in 1950 plaster ceiling comes back

nowwhatnapster

Almost all the ceilings in my 1950 ranch have a hairline crack somewhere. Usually in the center of the room. My father-in-law patched the cracks in two rooms. We primed and painted and the cracks came back after about 1 month.

The ceilings are smooth plaster. The first layer is a drywall like material that comes in rectangular sheets. Then on top of that is a layer of essentially concrete and then a thin layer of white substance that is incredibly smooth.

His procedure for patching the cracks (as best I can tell) was to open the cracks. paint cracks with killz2 primer, fill cracks with joint compound, sand, joint compound, sand, joint compound. prime ceiling, paint.

On one of the ceilings he used tape, not sure if mesh or paper. Also not sure what point the tape hit the ceiling. Either way, both ceilings cracked. The one with tape looks worse because the tape stands out more than the hairline crack.

So my question is, what did we do wrong? We have 3 more ceilings to tackle and 3 chances to do better. I am not going back to fix the two ceilings any time soon, more important things to do.

Also, separate issue. There was some water damage to a section of ceiling, likely due to ice dams. I picked out the loose material and now there is about a 4" hole in the ceiling. Should I patch with drywall? I have several 5" cut outs from the recessed lights I put in. I could make the 4" hole a 5" and use one of my cut outs?

If you need pictures I will try to get some this week.

Squished

I don't have a reply but I did patch cracks recently similar to what you did on my 1922 home. I'm interested to see what others reply in case my issue comes back like yours did.

Gary in WA

Center of the room ceiling cracks may be structural from your built-up beam (3 individual joists) below the center wall shrinking in size due to the climate change; pp.51; http://books.google.com/books?id=iwS...joists&f=false

Paper tape with setting---- not drying-type compound: http://www.usg.com/rc/technical-arti...ems-en-PM5.pdf

http://www.plaster-wall-ceiling-solu...wall-tape.html

Gary

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joecaption

Push up on them and see if they move at all. If they do you need more screws.
Those panels are hard as a hores heart. I predrill with a masonry bit and use ceramic coated decking screws to pull it in back in place.

chrisn

spell check

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joecaption

Exwifes last name was Hores, it's spelled right.

Maintenance 6

Wow! I was married to her sister.

boman47k

Maybe google 'plaster washers' and 'plaster ceiling repair'.