# alligator cracking lead based paint in bathroom



## protechplumbing (Oct 10, 2008)

My ceiling in my bathroom has alligator cracking in the paint. I sanded the paint and found that the source of the cracks is actually the plaster it self. This is a 1963 home in central Florida. The wall is 2 layers of drywall with a skim coat of plaster.

My question is this: Can I just scuff the paint and put a new skim coat of plaster on or do I have to scrap/sand all of the paint off before applying a new skim coat? There is at least 2 layers of paint existing. I suspect the base layer is lead based paint and the top layer is latex.

I want this done right so that the new paint will last, but sanding all of this paint is extremely laborious.

No, no children in my home. Yes, I'm wearing an approved respirator and have the room under negative pressure with tarps leading to the work area.

Keep sanding, scuff and skim or something else???

Thanks in advance.


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## protechplumbing (Oct 10, 2008)

Also, I'm installing an exhaust fan wired to a humidity to address future moisture problems.


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## Leo G (May 12, 2005)

Keep the alligator out of the bathroom then :laughing:

Sorry, couldn't resist.

Heat strip would probably easiest, and remember, you are the HO and don't have to follow any RRP regs for this job if you don't want to.


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## protechplumbing (Oct 10, 2008)

A torch?

Sounds like plaster over paint is a no-go then?


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## Leo G (May 12, 2005)

I'm not sure, but I wouldn't do it. If you wanted to skim coat it with drywall mud you could probably get away with it as long as all the loose paint was removed. But plaster would likely not stick to it. 

Not a torch but an electric paint remover. They have them that are RRP compliant but they are much slower. But it would be much better than sanding which is a messy, dusty operation.


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## protechplumbing (Oct 10, 2008)

Tried heat. If you get it hot enough to scrape, it loosens the plaster as well. I now have a basketball sized place to patch......


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## protechplumbing (Oct 10, 2008)

Some crappy camera phone shots.


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## Leo G (May 12, 2005)

Well that sucks, did not expect that. Is the plaster solid and strong everywhere else. Looks like you may be relegated to sanding it off. I don't think you would want to try chemical stripping.


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## VinylHanger (Jul 14, 2011)

I would spend 40 bucks for an 8 test lead-check kit and see if you really have lead paint. If not, you can just sand away. A 1963 house is a crapshoot, about a 50/50 chance. For 40 bucks you can save a lot of time,effort and worry if it isn't lead.


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## protechplumbing (Oct 10, 2008)

It seams to be holding onto the mortar(or what ever it is) underneath pretty good for most of the surface area. The only place it was loose was where heat was applied and a spot by the window. It's going to take all day tomorrow to sand all the paint off. The cracking is mainly on the ceiling, wonder why that is?......


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## protechplumbing (Oct 10, 2008)

VinylHanger said:


> I would spend 40 bucks for an 8 test lead-check kit and see if you really have lead paint. If not, you can just sand away. A 1963 house is a crapshoot, about a 50/50 chance. For 40 bucks you can save a lot of time,effort and worry if it isn't lead.


I really don't care too much if it's lead or not. Everything is already setup and I'm not sanding without a respirator leaded paint or not.


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## boman47k (Oct 13, 2006)

protechplumbing said:


> It seams to be holding onto the mortar(or what ever it is) underneath pretty good for most of the surface area. The only place it was loose was where heat was applied and a spot by the window. It's going to take all day tomorrow to sand all the paint off. *The cracking is mainly on the ceiling, wonder why that is?.....*.


Is there a floor above? If not, and if it is plaster, maybe it has lost its key. Maybe the cracking is just the result of gravity.

No experience with lead and very little with plaster, sorry.


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## protechplumbing (Oct 10, 2008)

No floor above. There was a radiant heat system in the ceiling that was disconnected years ago. Perhaps the combination of thermal cycling from the heat strips embedded in the rock and the condensation from the shower caused it to crack.


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## aptpupil (Jun 12, 2010)

a few options that i see. 1/4" drywall glued/screwed into the joists. seals in the lead, no worries about it adhering properly.
if the plaster is still keyed well enough and not moving when pushed up, then you can scrape the chipping paint off and then use plaster weld and a skim coat of joint compound set in window screen or fiberglass mesh.
both methods are preferable to taking down the whole ceiling or sanding it to death.


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## JHC (Jun 4, 2010)

Funny I wrote about this on Sunday. I did this job last week. 

Remove as much failing paint as possible. Zinnser shieldz, skim to smooth out the difference, and topcoat with a good paint. 

http://www.johnsonhomeconstruction.com/remodeling-articles/painting-problem-solvers-393


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## Frankawitz (Jun 17, 2006)

This is typical of plaster in bathrooms, then with the heating in the ceiling the plaster is being heated then cools which will cause expansion and contraction of plaster the start of paint failures, plus throw in the mositure from a hot shower, yeah we have paint and top coat loosens up the plaster comes off the scratch coat which is port cement sand, lime mix. I would use Durabond in brown bags fill the spots where your plaster fell out. then skim the whole ceiling with it then use topping compound then pull it tight then a light sand your ready for prime and paint.


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## protechplumbing (Oct 10, 2008)

Some pictures


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## protechplumbing (Oct 10, 2008)

1 more


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## protechplumbing (Oct 10, 2008)

Frankawitz said:


> This is typical of plaster in bathrooms, then with the heating in the ceiling the plaster is being heated then cools which will cause expansion and contraction of plaster the start of paint failures, plus throw in the mositure from a hot shower, yeah we have paint and top coat loosens up the plaster comes off the scratch coat which is port cement sand, lime mix. I would use Durabond in brown bags fill the spots where your plaster fell out. then skim the whole ceiling with it then use topping compound then pull it tight then a light sand your ready for prime and paint.


Topping compound?


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## Pete'sfeets (Mar 20, 2011)

I wouldn't worry about the patchyness of the old finish. Plaster the hard skim coat with sheet rock because that is a harder plaster and it adheres best. Use a good plaster knife's not a plastic one a three and six inch is fair. Sheetrock 45 is a good bet, prefill and then skim over, then use a good primer like bulls eye 123 , a flatter one like kilz is better but adhesion is a safe route. Since that type of construction doesn't use proper vapour barrier like now a days, go for the perma white satin, great for moisture, it can be tinted, doesn't have to be white. The type of construction, is four ft by two ft board but it isn't drywall, can't think the name but it tends to bow , swell one side and leave a checker pattern and really you'll need a twelve inch knife and a topping of mud compound to hide that. A cold ceiling in a sweaty bathroom collects lots of soap and mildew so before you plaster give it a wipe down, 'cause you cant do it after. Latex hides up the alligater lines because it is a rubbery flexible finish unlike oil-- that is brittle and then the cracks re appear.


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