Cracks in the ceiling

[Geoffrey]

Wow - you go away for a few months and everything's different when you come home.

Hopefully you're all stilll as helpful as you have been in the past, so here goes.

I've just removed the lining paper from my daughters bedroom ceiling (ok so it removed itself mostly). The old wobbly lime plaster ceiling is pretty good for 3 or 4 hundred years old but has some cracks. Should I use a lime mortar to fill them or will something like polyfilla be ok.
I was assuming I should scrape out along the cracks and then fill, but it might be less disruptive just to fill the cracks as they appear on the surface. I don't want to tempt fate and cause more of it to work loose from the laths although as I said it seems pretty sound.

Many Thanks in advance

Geoff

 

[BMcD]

As long as the "nibs" which hold the the ceiling to the lath are intact then you should be ok to scrape out the cracks to form a V dampen it down and fill with lime putty:silver sand at 2:1 and sponge finish with a fine grain damp (but not wet) sponge. Polyfiller and the like will work loose after a while where as lime will knit to the existing easier

 

[Geoffrey]

Thanks for the advice BmcD. That confirms my iinitial instinct - will give it a go tomorrow.

Geoff

 

[BMcD]

Be careful opening up the crack that you don't cut to deep through the plaster and into the lath and weaken the ceiling

 

[Nigel Watts]

I have recently stripped the paper from the ceiling of my future living room. The ceiling has many small cracks. Rather than trying to fill them all I am going to see how it looks after I have applied a couple of coats of homemade distemper. I am hoping that the distemper will be thick enough to fill them up. I will let you know the result of the experiment.

 

[Gervase]

I am hoping that the distemper will be thick enough to fill them up.

I would use limewash on a ceiling - lime has this marvellous autogenic healing capacity, so that small cracks and voids will be filled with lime in solution which will carbonate and give strength to the ceiling.

Dampen the ceiling thoroughly with a mist spray or stock brush first, and then spray llightly every few hours for a day or so between coats. Two or three coats should do the trick.

As it's a ceiling there's no worries about dusting or rubbing, and limewash does give the most wonderfully dense and opaque finish (as well as covering all sorts of imperfections).

All this, of course, on the understanding that all that's been used on the ceilng previously is limewash or distemper. Any oil or alkyd based paints would render the procedure pointless.

 

[Geoffrey]

Thanks to all. Works a treat - though I think next time (next room) I might try whiting rather than silver sand to get an even smoother finish.
Of course when I tried to scrape out a crack in the wall a whole load of infill to the timber frame came away and I ended up doing half the panel as well. Some things never change!

 

[Carol]

A few years ago I followed Nigel's advice to try a thick distemper on our ceiling, this has worked a treat and filled the tiny cracks well. My various efforts with the larger cracks have been hampered by my inexperience with the lime mix. Have been using lime putty and whiting in various combos, some work beautifully and others with the same mix don't. However, I get lots of practice as this ceiling moves with the seasons and new cracks always appear in the gypsum skim layer some idiot used 25 years ago.

 

[Nigel Watts]

I have been distempering one of my ceilings this weekend and can confirm that this wonderful material will hide a multitude of sins. I make my own distemper by soaking whiting in water overnight and mixing it the next day with a size made from rabbit skin glue. I never measure anything, just guess the proportions. It always seems to work OK.

I had to feather in a horrid patch of modern pink plaster from an earlier repair (I will take it down one day and repair it properly with lime when I install my ceiling rose, but that will have to wait as the wife is losing patience). I made a filler using some of my soaked whiting plus some paster of Paris.