plaster/rock lath ceiling construction
plaster/rock lath ceiling construction
(OP)
ceiling construction is as follows:
1.Floor joists
2. 3/8 drywall attached with nails at random spacings. Some of the nailings are with 2 nails at connection, spaced more than 12" o.c.
3. rock lath and finish coat of plaster below drywall.
4. the thickness of the ceiling (total) is up to 2-inches thick in the area of collapse. 16x16-inch section weighs about 20 lbs (about 11.5 psf).
5. no adhesive used in attachment of ceiling.
Ref: IRC Table R702.3.5 for additional info.
I opine that the weight of ceiling too heavy, any code references out there regarding allowable thickness of this type of ceiling construction? Otherwise, check out attached pic of nails used for attachment. I do have evidence of "double nailing" used at more than 12" o.c. but not sure if there were intermittent nails used.
Looking for comments.
Thank you.
1.Floor joists
2. 3/8 drywall attached with nails at random spacings. Some of the nailings are with 2 nails at connection, spaced more than 12" o.c.
3. rock lath and finish coat of plaster below drywall.
4. the thickness of the ceiling (total) is up to 2-inches thick in the area of collapse. 16x16-inch section weighs about 20 lbs (about 11.5 psf).
5. no adhesive used in attachment of ceiling.
Ref: IRC Table R702.3.5 for additional info.
I opine that the weight of ceiling too heavy, any code references out there regarding allowable thickness of this type of ceiling construction? Otherwise, check out attached pic of nails used for attachment. I do have evidence of "double nailing" used at more than 12" o.c. but not sure if there were intermittent nails used.
Looking for comments.
Thank you.






RE: plaster/rock lath ceiling construction
BA
RE: plaster/rock lath ceiling construction
RE: plaster/rock lath ceiling construction
One other consideration is that the rock lath and the old gypsum board, as well as the plaster, likely contain asbestos. Get it checked before you demolish.
Refer to ASTM C1063 and ASTM C926 for portland cement plaster. For gypsum plaster, see ASTM C843. The gypsum plaster should be about 5/8" thickness.
RE: plaster/rock lath ceiling construction
RE: plaster/rock lath ceiling construction