I have heard several stories about ceilings falling the have ceiling cable heat. Is there something about the heat or the installation that causes the ceiling to fall? Should I have a disclaimer on all homes with ceiling cable heat?
In my area heating cable imbedded in the ceiling plaster (old type) tend to ghost and hairline crack where they are installed. Most of them no longer work, and homeowners have installed electric baseboard or other heating means.
The new heating units are panels which sit on the backside of the drywall can cause ghosting on the ceiling side where installed. Some of these units had recalls out on some models as well.
Have never heard of a ceiling collapsing due to heat cables. Sounds like improper nailing of drywall.
If the ceiling is made of 12x12 ceiling tiles, they certainly will fall eventually just from age. If the ceiling is made of drywall, I’m in Raymond’s corner.
Here’s some information I want to share with you, just so you have some background information related to what the NEC says.
Article 424, Part V. Electric Space-Heating Cables
424.34 Heating Cable Construction
Heating cables shall be furnished complete with factory-assembled nonheating leads at least 2.1 m (7 ft) in length.
424.35 Marking of Heating Cables
Each unit shall be marked with the identifying name or identification symbol, catalog number, and ratings in volts and watts or in volts and amperes.
Each unit length of heating cable shall have a permanent legible marking on each nonheating lead located within 75 mm (3 in.) of the terminal end. The lead wire shall have the following color identification to indicate the circuit voltage on which it is to be used:
(1) 120 volt, nominal — yellow
(2) 208 volt, nominal — blue
(3) 240 volt, nominal — red
(4) 277 volt, nominal — brown
(5) 480 volt, nominal — orange
424.36 Clearances of Wiring in Ceilings
Wiring located above heated ceilings shall be spaced not less than 50 mm (2 in.) above the heated ceiling and shall be considered as operating at an ambient temperature of 50°C (122°F). The ampacity of conductors shall be calculated on the basis of the correction factors shown in the 0–2000 volt ampacity tables of Article 310. If this wiring is located above thermal insulation having a minimum thickness of 50 mm (2 in.), the wiring shall not require correction for temperature.
424.38 Area Restrictions
(A) Shall Not Extend Beyond the Room or Area Heating cables shall not extend beyond the room or area in which they originate.
(B) Uses Prohibited Heating cables shall not be installed in the following:
(1) In closets
(2) Over walls
(3) Over partitions that extend to the ceiling, unless they are isolated single runs of embedded cable
(4) Over cabinets whose clearance from the ceiling is less than the minimum horizontal dimension of the cabinet to the nearest cabinet edge that is open to the room or area
© In Closet Ceilings as Low-Temperature Heat Sources to Control Relative Humidity The provisions of 424.38(B) shall not prevent the use of cable in closet ceilings as low-temperature heat sources to control relative humidity, provided they are used only in those portions of the ceiling that are unobstructed to the floor by shelves or other permanent luminaires (fixtures).
424.39 Clearance from Other Objects and Openings
Heating elements of cables shall be separated at least 200 mm (8 in.) from the edge of outlet boxes and junction boxes that are to be used for mounting surface luminaires (lighting fixtures). A clearance of not less than 50 mm (2 in.) shall be provided from recessed luminaires (fixtures) and their trims, ventilating openings, and other such openings in room surfaces. Sufficient area shall be provided to ensure that no heating cable is covered by any surface-mounted units.
Embedded cables shall be spliced only where necessary and only by approved means, and in no case shall the length of the heating cable be altered.
424.41 Installation of Heating Cables on Dry Board, in Plaster, and on Concrete Ceilings
(A) In Walls Cables shall not be installed in walls unless it is necessary for an isolated single run of cable to be installed down a vertical surface to reach a dropped ceiling.
(B) Adjacent Runs Adjacent runs of cable not exceeding 9 watts/m (2 3/ 4 watts/ft) shall not be installed less than 38 mm (1 1/ 2 in.) on centers.
© Surfaces to Be Applied Heating cables shall be applied only to gypsum board, plaster lath, or other fire-resistant material. With metal lath or other electrically conductive surfaces, a coat of plaster shall be applied to completely separate the metal lath or conductive surface from the cable.
FPN: See also 424.41(F).
(D) Splices All heating cables, the splice between the heating cable and nonheating leads, and 75-mm (3-in.) minimum of the nonheating lead at the splice shall be embedded in plaster or dry board in the same manner as the heating cable.
(E) Ceiling Surface The entire ceiling surface shall have a finish of thermally noninsulating sand plaster that has a nominal thickness of 13 mm ( 1/ 2 in.), or other noninsulating material identified as suitable for this use and applied according to specified thickness and directions.
(F) Secured Cables shall be secured by means of approved stapling, tape, plaster, nonmetallic spreaders, or other approved means either at intervals not exceeding 400 mm (16 in.) or at intervals not exceeding 1.8 m (6 ft) for cables identified for such use. Staples or metal fasteners that straddle the cable shall not be used with metal lath or other electrically conductive surfaces.
(G) Dry Board Installations In dry board installations, the entire ceiling below the heating cable shall be covered with gypsum board not exceeding 13 mm ( 1/ 2 in.) thickness. The void between the upper layer of gypsum board, plaster lath, or other fire-resistant material and the surface layer of gypsum board shall be completely filled with thermally conductive, nonshrinking plaster or other approved material or equivalent thermal conductivity.
(H) Free from Contact with Conductive Surfaces Cables shall be kept free from contact with metal or other electrically conductive surfaces.
(I) Joists In dry board applications, cable shall be installed parallel to the joist, leaving a clear space centered under the joist of 65 mm (2 1/ 2 in.) (width) between centers of adjacent runs of cable. A surface layer of gypsum board shall be mounted so that the nails or other fasteners do not pierce the heating cable.
(J) Crossing Joists Cables shall cross joists only at the ends of the room unless the cable is required to cross joists elsewhere in order to satisfy the manufacturer’s instructions that the installer avoid placing the cable too close to ceiling penetrations and luminaires (lighting fixtures).
424.42 Finished Ceilings
Finished ceilings shall not be covered with decorative panels or beams constructed of materials that have thermal insulating properties, such as wood, fiber, or plastic. Finished ceilings shall be permitted to be covered with paint, wallpaper, or other approved surface finishes.
424.43 Installation of Nonheating Leads of Cables
(A) Free Nonheating Leads Free nonheating leads of cables shall be installed in accordance with approved wiring methods from the junction box to a location within the ceiling. Such installations shall be permitted to be single conductors in approved raceways, single or multiconductor Type UF, Type NMC, Type MI, or other approved conductors.
(B) Leads in Junction Box Not less than 150 mm (6 in.) of free nonheating lead shall be within the junction box. The marking of the leads shall be visible in the junction box.
© Excess Leads Excess leads of heating cables shall not be cut but shall be secured to the underside of the ceiling and embedded in plaster or other approved material, leaving only a length sufficient to reach the junction box with not less than 150 mm (6 in.) of free lead within the box.
424.44 Installation of Cables in Concrete or Poured Masonry Floors
(A) Watts per Linear Foot Constant wattage heating cables shall not exceed 54 watts/linear meter (16 1/ 2 watts/linear foot) of cable.
(B) Spacing Between Adjacent Runs The spacing between adjacent runs of cable shall not be less than 25 mm (1 in.) on centers.
© Secured in Place Cables shall be secured in place by nonmetallic frames or spreaders or other approved means while the concrete or other finish is applied.
Cables shall not be installed where they bridge expansion joints unless protected from expansion and contraction.
(D) Spacings Between Heating Cable and Metal Embedded in the Floor Spacings shall be maintained between the heating cable and metal embedded in the floor, unless the cable is a grounded metal-clad cable.
(E) Leads Protected Leads shall be protected where they leave the floor by rigid metal conduit, intermediate metal conduit, rigid nonmetallic conduit, electrical metallic tubing, or by other approved means.
(F) Bushings or Approved Fittings Bushings or approved fittings shall be used where the leads emerge within the floor slab.
(G) Ground-Fault Circuit-Interrupter Protection Ground-fault circuit-interrupter protection for personnel shall be provided for cables installed in electrically heated floors of bathrooms and in hydromassage bathtub locations.
Section 424.44(G) requires the use of GFCI protection where cables are installed in concrete or poured masonry floors, thereby reducing shock hazards to persons with bare feet in these areas. In the 2002 Code, the reference to conductive floor coverings was removed to clarify the requirement for GFCI protection in all the areas identified in 424.44(G), regardless of the type of floor covering over the concrete or poured masonry. This section was revised for the 2005 NEC by deleting the reference to spa and hot tub locations. In accordance with 680.27©(3), electric radiant heating cables are not permitted in these locations.
424.45 Inspection and Tests
Cable installations shall be made with due care to prevent damage to the cable assembly and shall be inspected and approved before cables are covered or concealed.
Joe you look like Joe Paterno of Penn State in that pic
Maybe so, I don’t wear a wig, yet!
Which one is Joe???
It’s difficult to tell, but I think the picture on the left is Joe, and the one on the right is Joe.
I saw him in Portand, Maine and it was the one on the left. The picture on the right must me a close relative, because there is some resemblance.