Plastered Ceiling W/radiant Heat

DesPro

I'm looking for advice on the best methods to repair cracks in plastered ceilings with radiant heat .
The job I'm working on has cracks in every room. Typically one long crack that runs the length of the room. Ranch style house built in the mid 70's , and the heat is still used .

__________________
"We are continually faced with great opportunities which are brilliantly disguised as unsolvable problems."
Margaret Mead

oldrivers

I dont understand what radiant heat has to do with anything millions of houses have radiant heat and plaster.

DesPro

Well maybe you're right . Perhaps radiant heat has nothing to do with it , but recently I've seen quite a few older plaster ceilings with radiant and these cracks seem to be consistent in each home.

__________________
"We are continually faced with great opportunities which are brilliantly disguised as unsolvable problems."
Margaret Mead

oldrivers

its an old house therefore the plaster is kind of old but 70s isnt really that old for plaster . Alot of those homes built back then had very bad foundations bad framing , lots of major settling. ive been in houses where its hard to walk accros the room without getting woosy from the slope. anyways the way i fix plaster cracks 1- take a utility knife and run it along the crack a few times making a bigger gap getting rid of the lose plaster, 2- then i prefill it with durabond let it set up and scrape down the ridge, 3- tape it with regular paper tape and taping mud, let dry , 4- coat tape with setting compound ,let set up really good because it takes longer on plaster to set up , lightly scrape, 5- recoat using lightweight mud, let dry over night. 6- recoat again using light mud , let dry over night, If joint looks like its good enough then sand

i usually do step 1-5 in the first day and then 1 day for each additional step however you could use setting compound all the way through. I use light on the second and final coat because its easier to sand flat unlike setting compounds wich set up but dont always dry throughout and are harder to sand perfectly flat. .

DesPro

oldrivers, thanks for your detailed advice . That's what I was looking for .

__________________
"We are continually faced with great opportunities which are brilliantly disguised as unsolvable problems."
Margaret Mead

Capt-Sheetrock

Ditto on what old rivers said, I have seen a bunch of that in the charlotte area. I figure its caused by the heating and cooling of the plaster, rather than the moving of the house tho.

Anyway, rivers is right about using paper tape rather than mesh, cause mesh will crack ANYTIME there is any movement. I know the mesh huggers will snap at that, but what your trying to do is fix a problem that will never go away. The goal here is to try to get it where the crack that comes back will stay behind the paper tape, can't get that with mesh.

Peace

kgphoto

Capt.,

How does it stay behind the paper? Won't it telegraph through? Paper doesn't stretch much.

Unless there is big movement, I haven't had recurring cracks on most if not all of my patches. I did have a No-Coat tray ceiling seam crack at one end. They hung a roll up door on the header and it twisted it enough to crack and pop the first 12 inches or so.

Capt-Sheetrock

Told ya the mesh guys would snap,,lol

The thing about this radiant heat cieling is the cracks are occuring from heating and cooling of the cieling in a rapid manner, NOT from structual movement, that is why the crack will stay behind the paper tape. Eventually the problem will surface again, this method will give you the longest amount of crack-free time you can get.

Mesh will not help this problem, as it does NOTHING, the crack will travel through the mesh to the surface.Using hot mud with mesh helps, but then again if you use hot mud and NO tape you will get the exact same results as hot mud and mesh tape,, hummmmmmmm

Step back guys,, they are about to make a mesh of this thread

or

"I'd rather talk about how I like mesh tape rather than try to address the problem of this ceiling"

taper71

Now that is just funny

kgphoto

You gotta weird idea of snapping Capt. So how does the crack travel through mesh and hot mud, but not paper and hot or regular mud?

I only asked for more information, didn't mention how much I like mesh, so why go there?

Frankawitz

kg when the heat is called for the plaster will exspans then when it cools it contracts. what will happen with your mud it will fall out between the holes in the mesh, I think Capt. should have said that, the paper tape will hold the mud in place. But it will hold a lot longer then mesh. i think there is something like 22 lbs per square inch before the tape rips.

kgphoto

Thanks Frank.