[MittensCat]

Can anyone share how they determine whether or not to pull plaster and replace with drywall. Beyond the basic push test to see if the keys are still intact, what factors determine your decision. I have a few issues to deal with but I'm not sure if it justifies ripping out the plaster. I've done a few rooms and it's not something I look forward to.

My Pros and Cons of removing plaster

Cons:
Dirty Heavy Labor
Need dumpster or dump site
Might be an asbestos danger
Must purchase material to replace

Pros:
Ease of access for updated wiring and insulation
Eliminates need to deal with surfactant leaching in bathroom and kitchen
Allows assessment of framing
Eliminates need to repair or hide cracks

I've pulled plaster before and it sucks. That being said, I'm not sure it would suck more than the effort required to achieve a smooth surface on a wavy ceiling that's layered with wallpaper and paint. Because the ceilings are so low on the second floor of my home, I was planning on installing recessed lighting. I thought that having bare ceiling joists could make the wire and light install go a lot easier. I'd have to clear the insulation from above as well and replace with new (which it needs anyway). The bathroom ceiling has bad surfactant leaching and I don't know if sanding or stripping it is worth it. If I was sleeping it would be a nightmare...

So for any of you who have been through a renovation before or work in the plaster/ drywall business, what would you recommend. Is there anything you would add to my pros/cons list? Thanks for any advice.

 

[mark sr]

I would add that plaster is considered a lot better/nicer than drywall BUT as you know sometimes it makes more sense to gut and start over. IMO it's pretty much a case by case decision.

 

[MittensCat]

I agree that it is much nicer. There is a plasterer who runs a business out of a garage on the street I grew up on. I try to pick his brain as often as possible because I'd like to have the knowledge and skills to do plaster. I work as a maintenance man at a catholic school and church built in the 1920s, so I'm around damaged plaster a lot. I appreciate the solidity and durability of plaster. Drywall does seem cheap but I think any of the quality and historical value properties of plaster are lost on the unfortunate demographic of my neighborhood. I figured that plaster and lathe wood add significant strength to a structure but my engineer father in law didn't think it would be so significant.

 

[ClarenceBauer]

To check to see if the Plaster Keys have or are failing try this method.
Using the heel of your fist strike the Plaster surface between the studs.
If you hear what sounds like falling gravel on the interior of the walls the keys are failing or have failed. If failure has already occurred the surface will move inward & outward when pushed on.
Do this test in at least 5 areas.
If you are not going to do any other up dates the Plaster can be saved & repaired not a big problem. If you can do drywall mudding & taping you can repair plaster with better results using the correct products.

 

[Bird Doo Head]

I'm not a drywall nor a plaster guy, so take what I say below with a big grain of salt!

I have lots of experience opening walls in old Detroit commercial buildings to install conduit. I'd always hang around when the plasterers or drywall installers worked so I could learn. (And pester them to death with my questions...)
It sure is an art to make beautiful drywall & plaster!

I figured that plaster and lathe wood add significant strength to a structure but my engineer father in law didn't think it would be so significant.
I'd have to think the lath, plus the resultant keys, would have a whole lot more stability than drywall, screws and mud. As I remember, plaster itself is stronger than even setting mud. (Ask my sandpaper)

A substitute for the solidity & durability of plaster, which I learned long ago from a plasterer, was to put cement backer board on the studs, then thin drywall over it. (Using something like Wonderboard for the backer- not Hardie board) He would use setting mud to adhere the drywall to the backer board.
You end up with a very solid wall with much of the sound deadening properties of plaster & lath.

If you do remove the plaster, be sure to work safely and be certain that your vacuum can filter the dust very well. (And mask on!)

I've wrecked a lot of vacuums where the dust gets through the filter and into the motor, thus grinding the insulation off the windings. (Worst one was Stinger vac. Dust hit the motor & exploded from the carbon brush sparks. Exciting, but stinky!)

Currently I have a Vacmaster VF409 and it filters really well. The incoming air & dirt goes into a bag. If any gets through the bag wall it has to go through a cloth filter, then a cartridge filter, then a HEPA filter. Fine Dust filters are available, as are HEPA bags. The air path is so that even if dust escapes, nothing passes the motor. (Before using it on sanding dust, I tried it on talc. Nothing came out the exhaust air.)

Plan B-
(Especially helpful if you think asbestos or lead might be present)
When vacuuming the floor, rig up a water bucket, similar to the ones used for drywall sanding. (Like Magna Sand-And-Kleen) Most of the dust gets trapped in the water before it goes to the vacuum. It's not OSHA for asbestos or lead, but better than nothing.
Being a DIY forum, here's a DIY example I found on line: https://www.instructables.com/id/Drywall-Sanding-Dust-CollectorSeperator/

I hope this helps & your project goes smoothly and enjoyably!
Paul

 

[MittensCat]

When filling holes and cracks in plaster, does the depth of the damage determine the product used to repair? For example, If the plaster is missing from the lath you'd need to start with basecoat and then finish with a topcoat, correct? Is a two layer process acceptable, or do you need scratch,brown, finish? For filling nail/ screw hole damage, is drywall compound/ spackling acceptable? I'm trying to educated myself on drywall finishing as well. I've watched guys use setting type compounds, fiber reinforced compounds, finish coats that are easy to sand. Lots of reasons and opinions out there.


Can anyone give me a run down on the products generally used and whether they are acceptable/interchangeable for both drywall and plaster. For instance, I've heard of a fiber reinforced product called Confil. Would this modern product be a substitute for basecoat? Is regular all purpose joint compound an acceptable top coat for plaster? I'm trying to understand where past and present meet with acceptable results. It may help me decide between repair or removal.

Thanks for any help.

 

[MittensCat]

Bird Doo Head thanks for the reply. I had just made my last post before I saw your contribution. If you answered any of my question already, I hadn't noticed.

 

[MittensCat]

Thanks for that water bucket idea Bird Doo. I've never heard of that. I try to be as hygienic as possible when I work. I don't have a hepa vac but I use a hepa filter and bag inside of my ridgid vac. I also exhaust the air (I realize the exhaust air needs filtered) and run air scrubbers made from 20x20 furnace filters taped to box fans. Also, always wearing a p100. My first post on these boards was in a panic over asbestos in plaster. I work in a grade school that has asbestos everywhere. I've reached a level of acceptance with it. My grandfather was a pipe insulator and I'm sure all of my aunts and uncles and dad were exposed all through their childhood. I try not to freak out over it, but I am very careful about myself and the risk to other people. Just hope the chrysotile is less persistent than amphibole. A lot of the studies seem to be corrupted by the industry.

 

[ClarenceBauer]

When filling holes and cracks in plaster, does the depth of the damage determine the product used to repair? For example, If the plaster is missing from the lath you'd need to start with basecoat and then finish with a topcoat, correct? Is a two layer process acceptable, or do you need scratch,brown, finish? For filling nail/ screw hole damage, is drywall compound/ spackling acceptable? I'm trying to educated myself on drywall finishing as well. I've watched guys use setting type compounds, fiber reinforced compounds, finish coats that are easy to sand. Lots of reasons and opinions out there.


Can anyone give me a run down on the products generally used and whether they are acceptable/interchangeable for both drywall and plaster. For instance, I've heard of a fiber reinforced product called Confil. Would this modern product be a substitute for basecoat? Is regular all purpose joint compound an acceptable top coat for plaster? I'm trying to understand where past and present meet with acceptable results. It may help me decide between repair or removal.

Thanks for any help.

For filling areas where the lath is exposed you should use a base coat material. In these areas you should clean the space between the laths, Than on the edges where the existing Plaster is to remain back cut the edges of the plaster (back cutting is cutting an angle @ say a 45* under cut so the new base plaster is under the existing finish)
The best material for this repair is a Perlite Plaster using this you only need to add water & can mix only what is need @ the time. Before the repair is started using a spray bottle mist the repair area down with water, or better use 1/2 water & 1/2 bonding agent like weldcrete or equal. One coat of base is fine. Leave the base coat back 1/8" or match the existing finish depth. For the finish use a Plaster product like USG Diamond Finish Plaster or equal. Also pre wet before applying the Finish. As for small nail holes use just the Finish Plaster.
When using mesh tape with a Plaster product I would recommend that you use mesh that is designed for the product selected example USG Diamond Finish use USG Imperial Brand Tape.
As for the use of a Joint Compound applied over Plaster in my 41 years of doing Plaster repairs I would NOT recommend it, it will fail & moisture will be your big problem that causes failure when it is used.
A setting would be the most compatible but I would only use it as a last result. If your existing Plaster is stable & NO other repairs are needed or will be included look at these products.
Plaster Magic = to reattach Plaster to the Lath.
A Veneer Restoration Plaster = example Master of Plaster or Equal.
The use of a Plaster product requires no sanding.
Do not let the Cost of the plaster products scare you off.
Call Lauren @ Master of Plaster @ ask her if you can get a wet sample to try on your existing plaster The number is 803-403-5252 tell her Hank told you to call I have NO connection I help get her started in her business.

 

[MittensCat]

Thanks a lot Clarence! Very valuable information. You are saying to use Perlite Plaster as your basecoat on the lath? Is quikrete bonding adhesive similar to weldcrete?

In what situations would the fiber tape be necessary?

 

[MittensCat]

I guess perlite plaster is just structolite basecoat...

 

[ClarenceBauer]

I guess perlite plaster is just structolite basecoat...

Yes perlite & Structo-lite are the same.
Most any bonding agent would be fine being it is an interior project.

 

[Bird Doo Head]

I also exhaust the air (I realize the exhaust air needs filtered) and run air scrubbers made from 20x20 furnace filters taped to box fans.
What A Great Idea!

I work in a grade school that has asbestos everywhere.

Like you, I'm kind of at peace with it.
I grew up in a Detroit grade school where chunks of ceiling would fall often. It had to be loaded with the evil stuff.
Back in the 70's, in the factory where I was an electrician, we would have to take down overhead "slow burn" wire. it was insulated with asbestos. We'd yank it down with chains on fork lifts, then stand there smoking cigarettes while waiting for the dust to settle. Then we'd sweep up the mess. Who knew?

I hope your project goes great, MittensCat. Keep us posted!

 

[MittensCat]

I didn't come up with the box fan and furnace filter idea. I read it on a wood working forum. I use them around the house to help with pet dander and dust. I have no idea how effective they are, but the filter will end up with a dark circle behind the fan blades.