Need some help please. Have been in the design/build business over 35years but have limited experience with lath & plaster interior finish. I’m in north central Texas area and this type construction has not been use for many, many years. This is my persosnal home. My wife’s father built in 1929.
One crack over my bed (1/8″ max.) the full length of the room and an area along one wall where it looks like the ceiling has dropped down and inch or so for a distance of about 4′-0″. It looks like the finish has come lose from the ceiling joist right at the wall. The joist is still in place. I thought I would put a 2x under the area and against the wall and jack it back up to the joist. The question is how do I keep it there? This was caused by water damage when I hail storm took out the old valley flashing(orighinal).
Then I have a few hair line cracks over door and window header corners caused by the heavy clay soil we have in this part of the country.
Would appreciate you council as to the best way to make these repairs. Preferably using material that I’m familiar with. Thanks.
Replies
Assuming you mean wood lathe.
Typical ceiling contruction had lathe attached to strapping.
A sagging section indicates that:
A) The strapping is pulling away from the joists.
B) The lathe is pulling away from the strapping.
C) The plaster is seperating from the lathe.
Ideally, you would be able to access from above, and determine the exact nature of the problem.
For jacking, a 'T' made out of 2x6 [on flat] works well. You can jack the 'T' up from the floor using a scissors, screw, or hydraulic jack. Sometimes I use one of those jacks designed to prop up cabinets during install resting on a sawhorse.
For securing, depends upon the problem. Screws, obviously. Plaster washers work well in general, though if you have problem "A" [above], big fender washers are up to taking on more weight. I find that using a spade bit to create a small countersink first for the washers makes finishing easier. They used to be hard to find, but HD actually sells plaster washers now.
If the plaster is coming off the lathe, it can be very helpful to get behind it to vacuum away any broken 'keys' and other debris that may get in the way of setting the ceiling back in place. Once done, you can apply glue to the area to consolidate the plaster, and help secure it to the lathe, prior to placing screws. I use Weldbond or wood glue. Soaks in beautifully.
Anyways, random solutions. Hope one applies.
My home is a typical lath & plaster home...built around 1939. It is horse-hair plaster keyed into the wood lath. There is no strapping attched to the joists, rather the lath itself is nailed to the joists. I have seen this configuration many times over in my area ( Pittsburgh, PA region) and have yet to see strapping used independently along with wooden lath.
Davo
"...and have yet to see strapping used independently along with wooden lath."
Perhaps it's a regional thing. Common in New England. Convenient for rewiring...
Probably is a regional thing with the strapping.
You know what I would truly like to see? an old time professional lather...complete with hatchet...only tool a pro ever used..hack the lath with the hatchet blade, then nail it in place using the hammer end. A fellow who went to my church was a professional lather. He's dead now...was in his eighties...people who knew him well said he was a whiz-bang...could knock out an entire house in a day...said he nailed em up like crazy. He didn't plaster...only put up the lath. Guess at one time he was pretty much in demand by all the local plasterers.
Nowadays with blue plaster board, I wonder if anyone still does the old school method. Sure would be a lot of work!
Davo
My father-in-law was a plasterer all his working life. Little guy with arms like Popeye.
Did it all, from wood to metal, to BB. He even had to slake his own lime.
Retired now, but 'consults' on my projects. Amazing to watch him lay down a perfect finish coat. It's a real art.
Imagine the sheer weight of the plaster that had to be put up for just one typical room.
In the "real" old days, those houses had to sit for a month or three for the plaster to cure out.
Ditto what csnow said about using screws with washers. This should hold fine, especially if ceiling just a little loose and not bulging terribly. After screws are in place, use setting type joint compound (the kind you mix...not the premixed stuff in a bucket) to patch the holes.
Use same joint compound to fill in your hairline cracks. Is better if you "v" out the cracks with a razor knife first. Moisten crack with water from spray bottle then patch crack with tape and joint compound. If you don't want to use tape, add white masonry sand in with compound mix before patching. Sand helps fortify compound, but really, mesh tape is better at keeping cracks from returning. For the record, adding masonry sand to the compound will also help to blend the old with the new cosmetically.
If you have no luck with screwing up the ceiling, then cut out the bad spots but leave lath in place if it has not pulled away. Screw drywall patch directly to the wood lath, then finish it with the setting type joint compound. If plaster is thicker than 1/2 inch, use 5/8 drywall and /or shim it out on backside so patch will be nearly in same plane as plaster...then coat and feather to same thickness.
Just my 2 cents.
Davo