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  1. #1
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    Default Derry derry down--but why and of what significance?

    First, I noticed a bit of crack along the center of the ceiling, near the paddle fan. I spackled it, but noticed another; caulked it, in case it was due to vibration. Next visit, I discovered it had returned and expanded a few inches, and I decided I had to go into the attic and see what was going on: had the fan support loosened? I still don't know: on my return visit, the ceiling was down.

    Back story: 1920s or early '30s cottage, rewired and plumbed in early to mid-1980s, fans supported directly to structure. Another layer added below ceiling drywall, screwed to joists. Later, floor and lighting put into attic for storage. Mid 1990s, central air added, mainly duct through attic and cellar--including more or less over this room. Original poured insulation, largely, in place for decades. Some history of water damage between roof replacements. Some months of no heat, some months with attic vent fan dead, which could have caused expansion, contraction, condensation.

    Question: what is likely to have caused this collapse, pulling all those nails and screws through the drywall? What is the likelihood that other rooms' ceilings are at similar risk, and how would you checkumm, ceiling fell--reduced.jpgjoists minus ceiling-reduced.jpgFallen drywall-reduced.jpgGoo-od cable, go-od connector-reduced.jpg or forestall similar problems?

    I have some slight suspicion around the old joist that looks like it was partly sistered? or extended? I haven't been in that ceiling for many a year, and haven't cleared away enough yet to see what that was about. The attic was used strictly for storage, and not terribly heavy storage--but of course the chipboard added some weight.

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  2. #2
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    Default Re: Derry derry down--but why and of what significance?

    David,

    I'm thinking it's rock lath, not drywall (rock lath was the precursor to drywall, except that rock lath was made to replace the metal/wood lath and scratch coat of plaster, typically receiving a browncoat and finish coat of plaster.

    Rock lath is typically 3/8" thick, and 16" wide by 16' long pieces (I've heard of wider and shorter pieces, but that 16" x 16' is what I have seen).

    I see nails overspaced (based on the nails remaining in the ceiling joists) and the piece laying upside down.

    Too few nails to hold the rock lath in place, add on some loose fill insulation (extra weight which was not planned for), replace the roof a few times, banging on the roof decking to remove old shingles and install new shingles, especially in the old hand hammering days (which tries to shake the rock lath off the bottom of the ceiling joists with each up and down hammer blow), then add on the weight of the attic floor (which bowed the ceiling joists and possibly made the nails/screws wallow out in size, reducing their holding power), and then nail on the attic floor (see roof replacements and trying to shake the rock lath off the ceiling joists), and ... yeah, I can see the ceiling falling down.

    Even without that stuff, the old nails may rust off, and you mentioned screws ... screws would not have been used originally, nails would have been, so maybe the screws were added whenever someone noticed the ceiling sagging?

    Just some first thoughts as I typed what I thought of.

    Jerry Peck
    Construction/Litigation/Code Consultant - Retired
    www.AskCodeMan.com

  3. #3
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    Default Re: Derry derry down--but why and of what significance?

    Quote Originally Posted by Jerry Peck View Post
    David,

    I'm thinking it's rock lath, not drywall (rock lath was the precursor to drywall, except that rock lath was made to replace the metal/wood lath and scratch coat of plaster, typically receiving a browncoat and finish coat of plaster.

    Rock lath is typically 3/8" thick, and 16" wide by 16' long pieces (I've heard of wider and shorter pieces, but that 16" x 16' is what I have seen).

    I see nails overspaced (based on the nails remaining in the ceiling joists) and the piece laying upside down.

    Too few nails to hold the rock lath in place, add on some loose fill insulation (extra weight which was not planned for), replace the roof a few times, banging on the roof decking to remove old shingles and install new shingles, especially in the old hand hammering days (which tries to shake the rock lath off the bottom of the ceiling joists with each up and down hammer blow), then add on the weight of the attic floor (which bowed the ceiling joists and possibly made the nails/screws wallow out in size, reducing their holding power), and then nail on the attic floor (see roof replacements and trying to shake the rock lath off the ceiling joists), and ... yeah, I can see the ceiling falling down.

    Thanks, Jerry. One of my failings is that I omit some detail, or provide it confusingly telegraphed. The original coverings, or rather the wall and ceiling coverings as of 1983, were I believe 3/8 in, but painted, not plastered. On top of this nailed finish on walls, and below it under ceilings, I added drywall, screwed to the studs and joists respectively. This enabled me to cut big honking holes in the walls to fish cables, in rewiring the house back in the 1980s. (Don't ask how I dealt with trim and molding.) I believe i screwed down the attic floor, but I don't remember for sure. Nonetheless, it, and the storage, were loads the builder may not have figured on.

    The big question I ponder is whether to consider adding a bunch of extra screws to other rooms' ceilings, or whether there was some especial cause here. Behind this room, I added an addition to the house in 2012. One of the images may show the ends of ex-denim insulation, which I used for that project.


  4. #4
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    Default Re: Derry derry down--but why and of what significance?

    David,

    Depending on the look you want, you could screw some 2x to the ceiling joists through the ceilings, then install shallow (low profile) "beams" perpendicular to the ceiling joists, with intersecting "beams" parallel with and under the ceiling joists, add sides/trim/moulding to suit ... I think "coffered ceilings" is the term.

    That would support and secure the ceilings up.

    I've seen that done a lot in large houses with high ceilings, but for decorative reasons, except you would want scaled down width and height.

    Without knowing the exact cause of this ceiling falling, I would presume that other ceilings could have the same issues.

    Jerry Peck
    Construction/Litigation/Code Consultant - Retired
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    Default Re: Derry derry down--but why and of what significance?

    Quote Originally Posted by Jerry Peck View Post
    David,

    Depending on the look you want, you could screw some 2x to the ceiling joists through the ceilings, then install shallow (low profile) "beams" perpendicular to the ceiling joists, with intersecting "beams" parallel with and under the ceiling joists, add sides/trim/moulding to suit ... I think "coffered ceilings" is the term.

    That would support and secure the ceilings up.

    I've seen that done a lot in large houses with high ceilings, but for decorative reasons, except you would want scaled down width and height.

    Without knowing the exact cause of this ceiling falling, I would presume that other ceilings could have the same issues.
    Interesting idea! I far prefer knowing what's going on, but sometimes it just makes sense to, well, get it handled.


  6. #6

    Default Re: Derry derry down--but why and of what significance?

    I think Jerry has outlined the issues well, it is impossible to know exactly what part of the "sandwich" caused the failure but the age of the layers just adds to the mystery.
    Re-securing the entire "sandwich" in all rooms makes sense! You can use Jerys method or you will need to consider how to secure the entire system.

    Jeff Zehnder - Home Inspector, Raleigh, NC
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    Default Re: Derry derry down--but why and of what significance?

    Quote Originally Posted by david shapiro View Post
    Interesting idea! I far prefer knowing what's going on, but sometimes it just makes sense to, well, get it handled.
    Making sure the other ceilings don't suffer the same ending does not mean you can find out what's going on ... er... what went on ... with the ceiling that fell.


    Jerry Peck
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    Default Re: Derry derry down--but why and of what significance?

    David,

    Instead of a coffered ceiling, the same 'holding the ceiling up' could be achieved by a series of 'trim boxes', and take a lot less work to do.

    Presuming the ceiling joists are 16" o.c. (adjust sizes for actual spacing), make a 16"x16" trim box around the ceiling fans/lights - that will support the approximate center of the ceiling. Then make a 32"x32" trim box, then a 48"x48" trim box. In a 12'x12' room, that leaves 4' around the supported ceiling area - put crown moulding around the ceiling to support the perimeter edges.

    Lots a designs could be used - starburst in the center at the ceiling fans/lights with 'x' pieces extending the starburst outward. Whatever fits one's fancy.

    Jerry Peck
    Construction/Litigation/Code Consultant - Retired
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    Default Re: Derry derry down--but why and of what significance?

    Thanks, Jerry. You're a creative man.


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    Default Re: Derry derry down--but why and of what significance?

    Quote Originally Posted by david shapiro View Post
    Thanks, Jerry. You're a creative man.
    Just throwing ideas out and seeing what "sticks to the wall", such as:

    What hobbies and interests one has?

    Trains? Hang a model railroad layout from the ceiling. Each track support goes out perpendicular to the track, each track support is into ceiling joists and is actually a support holding the ceiling up.

    Airplanes? Hang a collection of interesting planes from the ceiling. Each airplane is supported by a support the shape of a silhouette of the airplane, is attached to the ceiling joists and is there to hold the ceiling up.

    Have young kids/grand kids? Paint the ceiling light blue, cut wood supports in the shape of clouds - the clouds hold the ceiling up.

    Options are almost endless, all depends on what one is interested in ... and what their spouse/partner agrees to.

    Jerry Peck
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    Default Re: Derry derry down--but why and of what significance?

    Love the suggestions.

    In this case, it's more a matter of what will let me sell it in good conscience once the RE market revives, and what a purchaser will welcome. This is a house we moved out of a few years ago, that I've been slowly updating--mu-uch more slowly since the pandemic ended my use of outside workers.


  12. #12
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    Default Re: Derry derry down--but why and of what significance?

    Quote Originally Posted by david shapiro View Post
    In this case, it's more a matter of what will let me sell it in good conscience once the RE market revives, and what a purchaser will welcome.
    Ahh ... I see ... then do as I've seen in some of the NC houses I've looked at on Zillow and realtor.com the past year or two - the 4x8 ceiling panel edges (not sure what material the panels are as the photos aren't that good) have 1x2 strips covering the joints.

    Drywall without taped and finished joints? Thin wood panels?

    And the houses were not manufactured homes or modular homes either, some were quite old and had obviously been "updated".

    If the load of ceiling is reduced to 4x8 areas, the tributary load from each 1x2 secured to ceiling joists is reduced to 2' out from each supporting strip ... and there may be fasteners which are still holding on the intermediate joists ... much of the load was just taken off of those intermediate fasteners.

    To someone like me, foing that looks like someone cut corners on the installation of the ceiling (I have no idea what is above/was covered over), but I've seen it more than I would have expected (it's one thing to do that in a basement, but in the living spaces?), but it's apparently not "uncommon" in older houses.

    Maybe there was that small acoustical ceiling tile originally installed and that has been covered over.

    Larger older houses likely had plaster ceilings, nothing to hide there. Some have old wood T&G walls and ceilings, nothing to hide there either.

    Your case may be well suited for "beams" installed below the ceiling perpendicular to the ceiling joists, maybe 4' or 6' oc. That would support the ceiling joist-to-joist across the room, while reducing the tributary load from the existing fasteners and transferring the load to the beams.

    Last edited by Jerry Peck; 09-14-2020 at 10:15 AM. Reason: Speelin'
    Jerry Peck
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    Default Re: Derry derry down--but why and of what significance?

    To ease any concerns, disclosure should not be a problem.

    Beams in various rooms were installed after the living room ceiling fell. Cause of living room ceiling falling was not determined, while there was no evidence of sagging in other ceilings, to not have any concerns about the other ceilings, beams were installed underneath the other ceilings.

    Something like that.

    Jerry Peck
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    Default Re: Derry derry down--but why and of what significance?

    Quote Originally Posted by Jerry Peck View Post
    Ahh ... I see ...
    Your case may be well suited for "beams" installed below the ceiling perpendicular to the ceiling joists, maybe 4' or 6' oc. That would support the ceiling joist-to-joist across the room, while reducing the tributary load from the existing fasteners and transferring the load to the beams.
    That sounds like a very solid response.
    Thank you, Jerry. Your comment about the disclosure makes sense, too of course.


  15. #15
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    Default Re: Derry derry down--but why and of what significance?

    David,

    Here is an example of what I was describing in an older and smaller house:
    https://www.realtor.com/realestatean...-13151?view=qv

    Jerry Peck
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    Default Re: Derry derry down--but why and of what significance?

    Quote Originally Posted by Jerry Peck View Post
    David,

    Here is an example of what I was describing in an older and smaller house:
    https://www.realtor.com/realestatean...-13151?view=qv
    That may have taken a fair bit of work, but the result is quite a charming look.


  17. #17
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    Default Re: Derry derry down--but why and of what significance?

    I believe Hilario is another spammer

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