Charge by the hour, do job with high risk.

[andyeverett]

I have agreed to try and jack up some sagging drywall in a 40 year old house that was installed improperly. (See help I got in the following thread,

)

So I think I have come up with a plan of attack, and would like comments on that, but this is a job with the potential for a rooms worth of drywall to come crashing down if not jacked up properly (Christ, one rooms worth of drywall collapsing could lead to a shock- wave that brought it all down the rest of the sagging drywall in the house, I know that is a small likely hood but possible in theory). I have insurance have not had to use it and don't care to anytime soon. How should a job be handled that has a small but real chance of causing a lot of damage if things go wrong when the reward might only be a days pay if jacking is not very successful to a week or twos work if things work right.

The plan of attack is to test what can be done with one of the upstairs rooms, they are in the worst shape. Pick a room with not much stuff to remove and remove all stuff. Drop cloths cover the floor. Add a couple of hundred screws to the ceiling drywall, don't pull tight just shore up the drywall. Now using a drywall jack jack up one sheet gently and then tighten the screws. Repeat, with all the sheets, jack up a little, screw up. Repeat, repeat, repeat to the point where curved drywall starts "fighting" back. If the drywall has pulled up enough spackle and paint. 10 to 16 hours of work?

Thanks for any thoughts on either issue.

[nestork]

Andy:

I read through most of that thread you linked to, and I can't help but agree that if the sag is between the joists, then adding fasteners driven into the joists isn't going to help much.

That's because, just like wood, drywall will gradually bend under it's own weight. If you look at an ariel photograph of any city after a rain, you'll see puddles on all the flat roofs. That isn't because the weight of the water is causing the ceiling joists to bend, it's because over the course of time, the ceiling joists have already bent under their own weight and the weight of the roof. Heat and humidity accelerate that process so that steamed wood can be bent to form almost any shape, including the sides of a piano, violin or guitar or even woven into rattan furniture.

So, try putting in some additional drywall screws, but keep in mind that if there's no visible difference, you need to stop there. Otherwise, you're going to end up with an unhappy customer that doesn't want to pay you because you didn't FIX the problem with the ceilings.

[harry]

I agree with above. Probably bad workmanship compounded by getting wet/damp at some stage especially if the building has been MT for a while.

Our "drywall" is much thinner over here but is aluminium foil backed which prevents a lot of this problem. Damp can't get in. Also standard pitch for joists, trusses etc is 16".

[Ed Pawlowski]

This is a job to walk away from.

Only way I'd take it is to price it for complete removal and new rock. Nothing else is worth the risk and you end up with an unhappy customer and you work for $1 an hour in the end.

[trader4]

As I recall from the other thread, while there was a lot of SPECULATION that it was sagging between joists, an attic inspection showed that it was simply not screwed properly to the joists, ie lots of missing screws, and that's why it's sagging.

So, I see nothing wrong with Andy's plan. Personally, I would skip the extra work of installing screws part way first. I'd just jack it up using a wide piece of wood, like a 2x12 across an area that spans beyond two joists or so, like 4ft at a time. I'd know where the joists are, orient the board in the proper direction, jack it up, then screw it in place. See how it goes and learn.

I'd also have a written, signed contract with the homeowner that says something to the effect that they acknowledge that the drywall is sagging because it was installed incorrectly without screws, that jacking it may cause it to crack, break, etc, and in that case it may require that the drywall be replaced at their expense. This jacking method is an attempt to solve the problem without re-drywalling, but there is no guarantee that it will work..... etc.

[andyeverett]

The sag is perpendicular to the joists, I will try and link to a scan of a drawing of the situation below.

[Stormin Mormon]

My gut sense, is that the job is a loser. Bail out, and walk away from it.

)

So I think I have come up with a plan of attack, and would like comments on that, but this is a job with the potential for a rooms worth of drywall to come crashing down if not jacked up properly (Christ, one rooms worth of drywall collapsing could lead to a shock- wave that brought it all down the rest of the sagging drywall in the house, I know that is a small likely hood but possible in theory). I have insurance have not had to use it and don't care to anytime soon. How should a job be handled that has a small but real chance of causing a lot of damage if things go wrong when the reward might only be a days pay if jacking is not very successful to a week or twos work if things work right.

The plan of attack is to test what can be done with one of the upstairs rooms, they are in the worst shape. Pick a room with not much stuff to remove and remove all stuff. Drop cloths cover the floor. Add a couple of hundred screws to the ceiling drywall, don't pull tight just shore up the drywall. Now using a drywall jack jack up one sheet gently and then tighten the screws. Repeat, with all the sheets, jack up a little, screw up. Repeat, repeat, repeat to the point where curved drywall starts "fighting" back. If the drywall has pulled up enough spackle and paint. 10 to 16 hours of work?

Thanks for any thoughts on either issue.

[trader4]

Hide quoted text -

See my other post. Just span the sag with a piece of wood, jack it up, see what happens. If it goes back up without breaking, screw it in place. I'd use more screws than normal now, because it will want to return to it's bent shape. Too few screws and they could pull through. I'm actually wondering if nails might be better, because they have a much wider head. Usually screws are better, but this might be an exception. Something to keep in mind perhaps.

I'd also drive some finishing nails through from the attic to mark where the joists are before you start, perhaps snap lines, so it's easy to find and screw to the joists.

[dadiOH]

FWIW, the house of my wife's mother and step father had a sagging ceiling caused by a washer overflow in a room above. In their case, the edge of a sheet was hanging a good 6" down. FIL "fixed it" by pushing it up and more screws. Held for a while but ultimately the softened drywall pulled through the screws. When wife inherited the house we just had it removed and replaced.

I am definitely no expert on this but in your case I would try your fix. I suspect it will be fine but would *absolutely* include a "hold blameless" clause in the contract as trader4 suggested.

[dpb]

Not really very likely if it's been there 40-yr that one more day or two will be the camel's back day...

You can find out very quickly if there's any hope of any success or not and all you need is a couple of t-bars of tubafor of the right length to span the 4-ft width. You can just taper a little and wege against floor or get fancy and make them so can actually jack, but if you can flatten the board w/o cracking the surface paper it'll be apparent very quickly when you try. Place one on each side of each joist 6" or so from it to give you some working room between.

As someone else said, more than likely you'll have better luck w/ sheetrock nails than screws for this purpose as I agree w/ him you'll likely just drive the screw thru instead of pulling up. What you'll get you'll only get by the lift, _not_ by the screw/nail because they don't have the bearing area.

It's not a bad idea to stick a one or two 6" or so from the secure location and set it to the existing surface as some additional support so the sheet doesn't break at the edge.

Basic idea is ok but I think your approach is too conservative to be practical and won't have any better results than simply seeing if you can relift the board back into place w/o it cracking. Otherwise, you're talking so long that it would be cheaper to hire it replaced fresh if you are going to try to let it "relax" back.

As others noted, the likelihood of satisfaction here will be heavily dependent on the expectations -- it's going to have waves in it no matter what you do; hopefully they'll be small-enough to not be too noticeable but there's a lot of mudding/taping/leveling in somebody's future here, methinks...

[TomR]

I wonder if the sagging drywall will have collected any junk or debris in the spaces between the sagged drywall and the ceiling joists. If so, I wonder if that will cause a problem when trying to jack up the sags and try to get them to press up flush against the ceiling joists.

But, hey, I guess you could test it out in one room and see what happens.

Let us know how it works out.

[dpb]

On 4/14/2013 2:06 PM, TomR wrote: ...

...

If there's any amount, certainly. Would presume OP will have either checked and confirmed "not much" or will have to vacuum it out first.

If were this old house, the answer would be definitely req'd first step...

[clare]

I'd be concerned about the glue that was apparently applied to hold the drywall and didn'd do the job. What condition is it in, and how much space is it taking up????

[George]

You seem to be missing how human nature works. The OP is the expert who has advised the homeowners on a course of action. When it goes wrong he will be the bad guy no matter what is written in a contract.

If the OP were the owner and wanted to tinker that is a different story.

I am in total agreement with Ed. This is a job you walk away from.

[trader4]

quoted text -

There are a lot of jobs where some investigation or perhaps trying a more basic approach is warranted to see if it works before doing a more extensive job. I would never advise someone to take on a job where what they are doing has no chance of working, is not up to normal practices, etc. But what Andy is proposing to do here seems perfectly reasonable to me and it seems most other posters too.

And it's not like he's going to be doing $10K worth of work to find out if it works. One section of one room taking a hour or two should determine if it works or not. Any customer can stiff you at any time, by being unreasonable. Now, if something the customer already did gave me reason to believe they were unreasonable, then I would not take this job or any other job they wanted done. And as I said, I would make sure I had a written contract that says it may not work, the drywall may crack when pushed back into place, if it doesn't work, drywall replacement is necessary, etc.