What causes hair-line cracks in a plaster ceiling??

Question

Hi,
In my house the plaster ceilings have hairline cracks runing(usually) in rectangular shapes/patterns. And in most rooms one long crack that runs across the middle of the ceiling...

Any ideas what causes these cracks? I'm guessing that as it's teriary structure there is no major problem (I had a survey a while ago and no major structural issues showed up).

Answer 1

as a qualified plasterer it sounds like you have had a dodgy plasterer that hasnst done a good job

Answer 2

WOW!! I was just thinking about this and looked up cracks in plaster & there was your question. My house was built in 1948, and I live in Minneapolis, so extreme temperatures are common. Also, there was no proper insulation when it was built, so there is newspaper in the walls - yikes! I found out when I had my bathroom retiled, and sheetrock replaced w/Durock (sp?), which is waterproof.

I sometimes stare at the rectangular cracks in the ceiling and worry, but I know it is common and can be repaired. The only other, expensive option is to get the walls and ceiling redone and proper insulation put in. It doen't make sense to do this in an old house. This whole neighborhood is b/t 50 - 100 years old and the property values increased dramatically in the last three years since we moved here. People are buying these houses like crazy and I know the house is structurally sound b/c I had a great inspector before we bought it.

Don't worry about it. Just do the repairs if you want to paint. I think you can do it yourself w/a little online education b/c that is what I'm planning to do. Old houses are so cool! One reason I'm glad to have the plaster is we had a couple ice dams and ceiling leaks our first year, and b/c plaster is mostly water, there was no permanant costly damage done. Plaster does not mildew or rot when it gets wet. Just a little bubbling. No big deal.

Answer 3

Is it really plaster or is it drywall? There is a big difference. How old is the house? Where is the house? What do you mean by "teriary?" What do you mean by "survey?" Are they all hairline or are some wide enough to get a pencil lead into? How many rooms do you have and how many have cracks? How far apart are the cracks? About how many are 4 foot, 8 foot, 2 foot apart? These terms can be intrepreted different ways. Unless we know more facts, the answers will continue to be vague guesses and generalizations.

All structures settle a certain amount over the years. Some cracking is thus inevitable. How much is part of the issue. It sounds like you have an awful lot of them, perhaps too many.

How to fix them also depends on the additional answers to the questions that I asked. There are many techniques. Some repair techniques work MUCH better than others. I have seen some people's repairs last less than one year, others for over 7 years.

P.S. plaster and sheetrock are two completely separate products. They require completely different techniques to install and to repair. It is impossible to answer the question properly without us knowing which you have.

Answer 4

Your houses' structure naturally expands and contracts by a millimetre or two depending on the temperatures. i.e. contract in the cold expand in the warm. As paint/plaster doesnt stretch, it cracks! It happens to every home and should be nothing at all to worry about, especially if you have had an all clear from a structural survey.

Answer 5

Your house will expand and contract over the years. Plaster in the house will crack because of this.
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Answer 6

The cracks are nothing to worry about, they will be rectangular as all they are are the joints were the sheets of plasterboard meet, the joints should have been covered with a mesh tape (Scrim cloth) prioir to plastering to prevent the cracking.

Answer 7

You need to keep the temperature somewhat regulated in you're home, to much expanding and contracting going on. You can fill these cracks with door and trim caulk, let dry and paint. Do not use Behr paint, you have to apply 3 coats to one coat of Glidden. It will all be for nothing if you don't regulate the temp. in you're home. You must be living in or around New Orleans, would be my guess.

Answer 8

You could fill cracks with a good quality filler. For a bonding agent i exploit pva glue diluted with water; it really works very well and is clearly the equal as high priced bonding merchandise.

Answer 9

You shouldn't go at it so much and then you woudln't cause cracks in the ceiling below you!!! But seriously, I dunno what causes them but we have them too.

Answer 10

People having rough sex upstairs?