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Radiant Ceiling Heat and cracks? Normal?

Radiant Ceiling Heat and cracks? Normal?

Old 09-02-09, 05:59 PM
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Radiant Ceiling Heat and cracks? Normal?

I just bought a home and the house has radiant ceiling heat. We noticed cracks in the ceiling when we looked at the house but I assumed they could be filled and painted.

We do have a crack running the entire length of our family room from end to end which is roughly 24' long.

I guess my question is this, is this normal? The house is 35 years old.

Did they use plaster or is the ceiling's drywall for this type of heat? Will I be able to spackle them or is another method suggested?

Thanks for your help and reply!
Old 09-04-09, 05:04 PM
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If your house is only 35 years old, it probably sheet rock. I had a customer with a long room like that & it just kept cracking. My guess was that the sheet rock should have been hung across the joists instead of parallel. I guess the heat could cause it too. Do you see any discoloration in the ceiling?
Old 09-04-09, 06:17 PM
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Thanks, no discoloration what so ever and the cracks are very small in width I would say 1/16th of an inch at best if not smaller....

Old 09-06-09, 09:22 PM
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There are three ways electric radiant heat could have been installed.

1. Gypsum lath was installed then the electrician installed the radiant heat wire then the plasterer applied two coats of plaster. a brown coat about 3/4" thick and a finish coat smooth or textured. Given the newness of your house I am guessing it was not this. So. . .

2. Drywall was installed and the joints taped then the electrician installed the wire then the drywaller or a plasterer applied a thin coat of special plaster over the wires and finished it smooth or textured. If this is what you have be very careful if you try to dig out the cracks for you could cut or nick a wire and the system is ruined in that room. Or. . .

3. Drywall was installed then the wire as above then the drywaller or a plasterer applied a coat of some kind of material in which the wires were embedded and while still wet another sheet of drywall was installed. I don't know how they attached it without getting a wire. Maybe they held it up until the plaster or adhesive or whatever bonded and then they went on. Ive only heard about this. I've never done it or seen it done.

Here are some things about radiant heat and gypsum products. Heat drives off some of the water of hydration in the gypsum molecules. This is what makes it especially fire proof. But seems like low heat over long periods of time does the same thing for I have seen the plaster behind hot water radiators that was so soft you could poke through it with your finger. This after many years in service. Now I think the same thing probably happens with electric heat over time. My dad plastered acres of radiant heat and I asked him a while back what the plaster was like after 40-50 years and he said it cracks.

You want to know what to do. This is what I think I would do if it were mine. Google NuWall or some permutation of that name and you should find a system that uses some sort of high powered paint into which is embedded a fiberglass scrim. This is a mat not woven fiberglass. Now you could use that system but what you really want is that kind of mesh without the high powered paint. This is the same kind of mat that is on the surfaces of Dense Armor Plus drywall.
Use a setting type of joint compound and spread on a strip as wide as the mat going across the room either the length or width whichever you think you can handle before the mud sets and embed that mat into the mud and pull it as tight as you can. When you get the whole room done this way then skim it again with all purpose mud and skim it again if you think it needs it then sand and texture and paint or sand. touch up sand prime and paint if you want it smooth.

Oh, I thought of one more thing. All of this presupposes that the plaster is still bonded and is not loose. If it loose you will have to fix it and this is very ticklish because you can't damage the wires.

I hope this helps. Please let us know how it goes.

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