plaster vs. drywall

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SiouxCItySioux
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plaster vs. drywall

Post by SiouxCItySioux »

we love original plaster walls, but i'm beginning to become very aggravated with the ones in our home. we have been trying to retain as much of the original plaster as possible, but i'm beginning to wonder if it's actually worth all the effort.

for example, a year ago, we began restoring our dining room. the walls weren't really in "bad" condition, considering they are 115 years old. where they were "soft" or "hollow" sounding (like, where the smooth final coat had separated from the second rough coat) i removed it all down to the lath. i then screwed 1/4" drywall into the areas to fill the voids and then filled on top of that with mud to bring it all up to the same level as the surrounding plaster. after getting all the major work completed, i then used the mud to skim coat the walls several times, sanding in between each coat, to obtain a nice, smooth and level surface. this was all completed and painted by the end of may 2004. now, after going through a full year of seasonal changes, the walls are showing unsightly hairline fractures where the original plaster was cracked before we started.

we live in iowa, so our house has to go through some wild temperature extremes. so, it seems no matter how much effort we put into repairing the plaster, it's just going to crack again as the seasons change.

so, my question goes out to those who have removed the original plaster and replaced it with drywall. does the drywall crack, like the plaster, or does it remain nice and smooth throughout the seasonal changes?

i've always heard that plaster walls provide better insulation, like keeping the house cooler in the summer (we have no a/c) and warmer in the winter by retaining the internal temperature better than drywall. i'm not sure if this is true or not. i've also heard that plaster keeps out more outside noise pollution, but i'm not sure if this is true either.

any info on this subject would be greatly appreciated!

Dave
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Post by Dave »

Wow, what a good question to get voices raised, tempers fired up and emotions elevated. Before this thread is finshed, someone will have a black eye and several life-long friends won't be speaking anymore.

So let's get started....

Here is my opinion on the matter, culled from a previous post I made, and I realize it is only my opinion...

Saving plaster is a very noble goal, one one that smacks of a preservationist approach, but the problems you mention, and others, are ones that need be considered carefully when deciding.

I've always been a staunch preservationist when it comes to old homes. Every door molding, every piece of brass hardware, the floor plan, every historic treasure must be restored and celebrated. So I often amuse myself by sitting and wondering why I'm so liberal in the replacement of plaster; why is it this one aspect escapes my preservationist radar?

I think I let plaster off the hook for a few reasons. If I have to remove plaster, I replace with drywall because:

1. It's seems to be an endless job repairing plaster. If I repair all the cracks and the loose plaster in my house, in 5 years I'll be working on fresh spots the need repair. This will go on forever.

2. Bradbury & Bradbury wallpaper is going to be very expensive. If it cost what it did in Victorian times, I might be inclined to paper the plaster ceilings as they are. But now I want a sound base.

3. I dont like using "old work" electrical boxes when installing new outlets. By taking enough of them out, I see how tenuous their solidity is being attached to plaster.

4. It's important to me to make sure the house is sound on the inside. Removal of the plaster allows the entire inside envelope to be inspected and assesed. Unseen issues with water, bugs, etc can be found. I found dried water stains in my work, this gives me good clues what to keep my eyes on outside on the clapboards and which ones to examine more closely.

5. Knob and Tube can be removed easily. New NM electrical wire becomes childsplay to install. No drilling blind holes, no fishing with wire snakes. All NM cable can be secured correctly. Telephones, cable, can be run discreetly.

6. Plumbing can be assessed fixed. Lead pipes can be replaced.

7. Insulation. The most important aspect. In cold climates, an insulated wall should always have a vapor barrier. (See my big fat rant in here http://www.oldhouseweb.com/phpBB/viewto ... highlight=
Blown-in wont get a vapor barrier. Expando foams will inhibit anyone's desire to run a new wire -forever-

8. In addition to insulating with a vapor barrier, I can seal cracks and other points of ingress which cold air finds

9. Once the drywall is skimmed and wallpapered. There's no visual difference..

10. By doing all the above, and insuring it's all done correct, I remove the possiblity that future generations do it carelessly. For example, I will put in a proper vapor barrier, run safe and efficient wiring, remove decaying lead pipes. Eighty years from now, when the next family owns the house, they will not face the temptation to blow in paper pulp and the sills will not rot from it. They will not wonder about crumbling knob and tube, thus will have one less reason to have an uncaring contractor rip the place apart. There will be no unseen leaks to slowly rot the structural fabric of the place. So in a convoluted sense, the benfits of drywall can actually play a part in maintaining the character of the house, in the long term.

It is not my intent to push a certain ideology in regard to plaster. I can see the issue from the other side and I really do appreciate the historical continuity of an original plaster wall, but I did want to develop more fully, the devils advocate position creeping into your desire to retain the plaster. The points above should be part of a decision.

Dave

Guest

Post by Guest »

thanks dave!

oops! didn't mean to start a war or anything. i hope it doesn't come to that.

anyway, i agree with you on most of the points you make (#s 1, 3, 4, 5, 6). #2, however, isn't really applicable at this point. sometime, in the future, we'd like to add some b&b paper, but it's just too expensive to do right now.

#7, scares me. we did blown-in insulation in 2 of our rooms before i knew the horrors of it. now, this is also one of the reasons i'm debating with the "save the plaster" vs. "replace it with drywall" issue.

like you, i try to save every little bit of originality that i can find. this is why i'm really wrestling with destroying plaster walls that aren't totally crumbling down around me.

one thing though, i understand the concept of how the vapor barrier works, but, where does the moisture that the vapor barrier traps end up settling?

Guest

Post by Guest »

sorry, i somehow got logged out. that "guest" post reply above was by me.

SiouxCItySioux
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Post by SiouxCItySioux »

darn! it did it again! this just isn't my day... :)

Dave
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Location: Salem MA
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Post by Dave »

Supposedly it stays trapped in the air inside the house rather than condensing inside the walls. It would be interesting to see the difference in interior winter humidity between 2 identical houses, one with a vapour barrier and one without.

Dave

franklyspeaking
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Post by franklyspeaking »

I sympathize with the plaster....it is a continual maintenance issue. Drywall is not problem free, but it is almost maintenance free. If we had had plaster in our old house, we wouldn't have any now.

As far as vapor barrier goes, in the winter time the vapor barrier seals out inside humidity from condensing inside the colder exterior walls. In the summer time the insulation between the cool air conditioned walls helps prevent condensation from the more humid exterior. If you wrap the exterior in tyvek or something similar this helps prevent humidity (moisture) from getting into the wall (i.e. moisture barrier on both sides of the wall).

As far as the inside humidity, I would guess that the number of air exchanges is likely what will control interior humidity. I think vapor barriers would have a neglible effect upon interior humidity. 'Just my opinion.
Jerry

catya

Post by catya »

OK well I'll provide the alternative view here.......my plaster repairs have lasted 5 yrs now and I haven't gotten any recracks.

Have you tried using a bonding agent? It improves adhesion between new plaster and old, between drywall patches and plaster, between the wood lath and the plaster. Elmers pro-bond is one brand. All around great stuff. Also, I know some will argue with me but Ive heard drywall mud is soft and prone to re-cracking, it makes a nice easily sanded final coat but as a base coat it doesn't have the strength of "real" plaster.

I dunno, I suppose some houses might just move around more than others and if its truly that much of a p.i.t.a. I suppose drywall could be lesser of evils.... but just for the record, its is not really all that easy or a quick job either... especially if you do it right... so I think its worth ruling out all the other possibilities first.

SiouxCItySioux
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Joined: Fri Nov 19, 2004 7:44 pm
Location: Sioux City, Iowa
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Post by SiouxCItySioux »

thanks dave,

i had just imagined the moisture condensing on the plastic itself, and then running down and rotting out the floors or getting absorbed into the bottom edge of the drywall. but, after thinking about it a little more, i guess the insulation in the wall keeps the air temp regulated enough so that doesn't happen.

thanks catya,

the cracks that keep appearing in my plaster are where it was originally cracked before i skim coated. they usually run vertically or horizontally, and sometimes create "squares" or "rectangles." so, it leads me to believe that it's caused by the lath expanding/condensing with the heat and cold. when doing the repair work, wherever the plaster felt "loose" i used those plaster screws with the metal mesh buttons to tighten it all up.

i've never tried a bonding agent, but the repaired areas that have the drywall patches and mud are fine, so far. i haven't noticed any cracking in these areas at all.

we did have to remove an entire ceiling in our second bedroom because the plaster had too much water damage. we replaced it with drywall and it still looks great. this is what made me seriously start thinking about the plaster vs drywall issue.

true, correctly installing drywall is a pretty involved job, but repairing original plaster is pretty involved in itself. i guess what i'm getting at is if both are a lot of work, i'd like to spend the time doing the method that gives me the most longevity. bottom line, if i tear out all my plaster, install drywall, and then in 5 years still get cracks, then i'm probably better off just keeping the plaster and living with the ugly cracks.

mwalker
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Joined: Wed Dec 17, 2003 10:29 pm
Location: Bergen County, New Jersey

Post by mwalker »

One point raised earlier in this thread reminded me of something I read
in this month's issue of Old House Interiors -

Bradbury and Bradbury is going out of the wall paper
business within the next year...
Mary

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