Cracked joints with radiant ceiling panels

[Chris Bernhardt]

I commonly see cracked seams/joints ceiing facings in older homes with radiant ceiling heat due to thermal expansion and contraction of the panels. The condition appears cosmetic and I make mention of them but are they in need of repair for other than cosmetic reasons as long as they are still working?

Chris, Oregon

[sbrooten]

Chris, Is it really thermal expansion or just the "normal" settling. I really haven't seen any joint failure that appeared to be from thermal espansion, and this stuff is pretty common around here. If it is functional, I would most likely see it as a cosmetic repair unless there are some other circumstances involved.

[Jim Katen]

Originally posted by Chris Bernhardt

I commonly see cracked seams/joints ceiing facings in older homes with radiant ceiling heat due to thermal expansion and contraction of the panels. The condition appears cosmetic and I make mention of them but are they in need of repair for other than cosmetic reasons as long as they are still working?

Chris, Oregon

Hmm. I see a fair amount of radiant ceilings but they hardly ever have cracks. In my experience, that's not normal.

Do you have pictures?

Also, there are two basic kinds of electric radiant ceilings. One uses factory-made drywall panels that contain the heating cables. The other uses regular drywall, the heating cables are stapled up and a plaster coat is applied on top. Which kind do you see cracking?

- Jim Katen, Oregon

[Chris Bernhardt]

Now that I think about your right. The radiant ceiling systems with drywall I haven't seen with these kind of cracks unless there had been some movement in the structure.

These panels that I am asking about are smaller in length and breadth and appear to be plaster and I recall seeing this kind of cracking with non-radiant ceiling systems but not to the same degree.

The cracks are closed not open and the panels remain in plane. the cracks appear to follow the outline of the joints. I took a picture but the cracks didn't show up well.

Did they use to finish the joints with paper tape or in a plaster system they don't? I guess what you are saying is that even if the joints are not open or panels out of plane that the cracking indicates some flexing in the structure? The house was out in Monmouth and had a flat roof 4"x10" beams and 1" tongue and groove decked over by plywood built in 1961. The living room and dinning room area ceiling had a 2" - 3" sag in it but interestingly the hallway is where I saw the most cracking.

Chris, Oregon

[Jim Katen]

Originally posted by Chris Bernhardt

These panels that I am asking about are smaller in length and breadth and appear to be plaster and I recall seeing this kind of cracking with non-radiant ceiling systems but not to the same degree.

Interestingly, the last radiant ceiling I saw in Monmouth used 12"x48" rock lath. Was yours like that?

. . .Did they use to finish the joints with paper tape or in a plaster system they don't?

They used paper tape on the full-sized drywall sheets. I don't know about the rock lath. They might not have.

I guess what you are saying is that even if the joints are not open or panels out of plane that the cracking indicates some flexing in the structure?

Not necessarily. Cracking always indicates movement. In my experience, the normal thermal movement of thermal expansion & contraction isnt' great enough to overcome a properly prepared joint. Maybe you're seeing improperly prepared joints.

The house was out in Monmouth and had a flat roof 4"x10" beams and 1" tongue and groove decked over by plywood built in 1961. The living room and dinning room area ceiling had a 2" - 3" sag in it but interestingly the hallway is where I saw the most cracking.

Chris, Oregon

The sagging would worry me more than the cracking. I've heard of these ceilings falling.

- Jim Katen, Oregon