Fixing wavy drywall at the plaster stage
Hi Everyone,
I am refinishing my hallway now, it is a four story walk up brick building. The stairs are in teh center of teh building and are surrounded by about 8″ brick walls. The entrance hallway in my unit is sharing one wall with the stairwell.
The brick wall in the hallway side has horsehair plaster directly on the brick. At the lower part of the wall, there was wainscotting that was attached to some furring strips that were nalied to the brick w/ those old fashioned hand made nails.
I pulled everything off the brick and attached new 1 x 3 furring strips by drilling the masonry and using tapcon masonry screws and liberab liquid nails (to stop the furring strips from moving if there were any voids between the strip and the brick). This was by far the worst task to date. What a pain!
Anyway long story short is I screwed my drywall up and realized the brick was not as straight as I ASSUMED. (I’m still learning, and I know…now never assume anything)
It’s not the end of the world, I just plan to skimcoat a couple of areas to bring it out about 1/4″ to 3/8″ at the worst condition. The area where the problem is apppears depressed and it’s about 5′ in diameter.
>What type of plaster should I use, is teh green top usg stuff okay here or would you reccomend something else?
>I was going to screed it with a 6′ scrap piece of poplar that has recently been ripped on a table saw, because its what I have on hand thats long and straight, then I was going to finish it a little with a 12″ taping knife. Is this a good/bad plan?
>How can I eleminate those pesky little bubbles in the mud that materialize as little voids when you sand after? I want it super smooth so it blends when everything is primed and painted.
> should I bring it out with a couple of layers, so as not to put too much on at once?
Thanks in advance for your help.
Edited 2/24/2006 10:31 am ET by xosder11
Replies
any takers?
Since people don't seem to be exactly poucing on your post to reply, I'll give it a shot and that may start the flow! I know very little about drywall. I suppose youve got it all screwed down and taped, so starting over with shims and string lines is put of the question? Next time.
Yeah. I would try what you suggest--use topping compound (is that green topped, or blue topped tub?--I told you I don't know a lot) and the screed idea sounds like a good one--put exess compound on the last coat and strike it off with the screed. I would do it in layers to prevent cracking and to allow it to dry more quickly--maybe even use the screed or a taught line to get the right level and put blobs of compound just touching the string and let them dry and then use those as references. I imagine it would be a lot like fairing a boat hull or repairing dents in a car body.
Use the widest knife you can handle. You might even try a mason's float--the thin metal rectangular ones with the L-shaped handles on top. Those do a good job of smoothing large areas. Maybe even dash the surface with water (or spray judiciously with spray bottle) as you work it. As far as bubbles, I've heard, but haven't tried it, that adding a little dish washing detergent to the mud will help eliminate those. A strong light close to the suface ("raking light") will show up imperfections by casting shadows. Also running your hand over the dry mud will tell you where there are ridges or rough spots.
Good luck.
Danno, thanks for the reply, I know the topic does not really elicit much excitement, but I was hoping a couple pro's, or people with experience had some tricks up their sleeve for me. "I suppose youve got it all screwed down and taped, so starting over with shims and string lines is put of the question? Next time"I was thinking, after the fact, that that was how I should have done it, but There will be a next time I'm sure.unfortunatly yes at this point. It's really not that bad so Im sure I can get the level of straightness without too much extra hassle, and in all honesty, I'm asking for perfection on a wall of a building where if you knock your beer over you have to chase your rolling bottle to the "low side of the room" But I am just doing this work because, as sick as it may sound, I'm actually enjoying it. And regardless, the end result of all my projects is always WAY better than what was there to start.Thanks again,
Andrew"I'm your huckleberry"
I'm just like you two fellas I don't know Jack S about DW,...but that thickness you mentioned seems too deep to try and fill with one or two passes, I would think a heavy coat would just crack...just my 2¢
Whatever man. I'm just glad that you decided to post in my lame azz thread. I got excited to see the gold star. : )
"I'm your huckleberry"
I'd rather start over. I think it would be easier than filling, and be a smother job.
If the dip is pretty localized, AND you dount have to worry about trying to hit that furring with other things mounted on top of the drywall, here is a thought:
1. Figure out the dimensions of the dip, use a string or three so you know exactly where the drywall needs to be.
2. Demud the screws in that dipped area and back them out so the head lies just under the string. The drywall may or may not back out with them. You may have to slip a hook into a hole to encourage the wall out to where you want it to be.
3. Drill a few 1/4" holes in line with your furring strips in the dipped area. Stick in the tube from a an expanding polyurathane foam can like Great Stuff, do not use the latex kind, and shoot some in. If you have to hold the wallboard out, use a long board flush to the wall and tie the hook to that too keep it pulled out untill the foam dries.
4. After the foam has cured, you can tighten the screws again.
I've never done this before, but I did just finish doing about as much mudding as you are thinking of doing. Try this first to keep it simple. Adding that much material is asking for problems!Rebuilding my home in Cypress, CA
Also a CRX fanatic!
Your idea of "spray foam shims" (my wording) sounds like it would work well. I was thinking along similar lines--how to shim without removing the drywall, but didn't think of the foam. Good idea!
Perhaps it would be easier and quicker to rip out the drywall and start over?
I was gonna suggest knocking the whole wall down ...;>)
Unless you are more skilled with a trowel than you were setting the furring to the brick, it will be easier to unscrew the wallboard and shim, then screw it back on or replace it.
Second - you need to decide whether you want plaster or sheetrock. you have plaster in the rest of the building. Drywall/sheetrock is not plaster, not is the premixeds finishing compound. If you want plaster, you have to mix up some plaster. If matching materisals is not important to you, then you can tie this drywall to the plaster.
You will have to vacumn the grit loose from the joint, and paint on something ( Bonding agent like Acril60) for a fixative and bond to the old plaster.
For the finish and taping, a setting type compound like Durabond is much harder than drywall compound is. That could be important to avoid damage in a hallway.
If you try to just coat over the situation you have now to build it up, it could take 6-7 coatys. a Thick coat of drywall mud will shrink and alligator, requireing numberous fill coats and will take long to dry between coats whereas Durabond will set up in an hour or so.
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Taunton University of Knowledge FHB Campus at Breaktime.
where ...
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I'm not a real mud guy, but I've done a lot of repairs and hung a few sheets. I don't think I could "straighten" the wall in question. Maybe someone who does a lot of skimcoating could, but that's not me.
Any chance of adding another layer? Maybe using shims/furring to level what's there and adding 1/4" drywall. If that's a no go, I would consider re-doing it. After all, you'll spend more time taping/spackling than you will hanging.
-Don
I agree with Piffin. "Drywall" drywall is not designed to be skim coated. for that you need either blue board, rock lath, or flip the drywall and use the back side. However, you could put a bonding agent on the drywall and skim coat with USG Diamond coat. Whether or not this will get what you want, I don't know.
I'm not a fan of mixing drywall and plaster. Drywall looks too flat next to plaster, and is not as hard.
But then again, you haven't seem my pretty pathetic attempts at patching my plaster...
"But then again, you haven't seem my pretty pathetic attempts at patching my plaster...":)There is a way you can fix that little problem for us...
Welcome to the Taunton University of Knowledge FHB Campus at Breaktime. where ... Excellence is its own reward!
If I do, I add in the pictures of my intestines, with the Crohn's disease and ulcerative colitis - which is why the patches are not finished.But I did get pictures of my porch from 1942 which I'll post. Then everyone can see what is wrong with the current design.
Take this with a grain of salt....I'm a DIY'er here...but I'm fixing up my very old house...Nothing is square...I've DW'd the dinning room walls, ceiling, Baby's room walls and now a completely new bathroom
One thing I can tell you is I HATE TAPING AND MUDDING...has to be the worst job.
Anyway...like you I have warped DW in spots...very slight 1/4 bows from time to time. What I've done is skim where it's even and lay it on thick where it's not. Sand the line very close and put on a second coat. Sand. and then go out with an 8" blade and sand...then go out with a 12" and sand.
The further out I go the less bow you can see....it'll take awhile to get that far out but it works for me.
But Ive got maybe 5 posts here...and come here to read mostly...so re-read my first line.
Don't be making things harder for him now. If you have to sand between cpoats, you are not putting it on right in the first place, and theact of sanding makes it harder to obtain a decent finish coat, unless you blow or vac all the dust off each time. No wonder you hate doing this. You're making it three times as much work
Welcome to the Taunton University of Knowledge FHB Campus at Breaktime. where ... Excellence is its own reward!
KISS = keep it simple stupid!
Go get some setting type of drywall compound ie sheetrock 45 min (the powder)
Mix it up smack it on, use your long stick to knock of the highs. clean tools and wait 60 mins and do it again. you will soon be at the right hight.
Use regular mud and finish with light sanding. this is no more a problem than a butt joint!!
First, if the joints haven't been taped, I would pull it off and shim the strips so they're straight. If they have been, I would do it anyway since you're going to hate the end result if you don't.
Second, the joint compound from a bucket shrinks and cracks if you put it on heavy. It also takes forever to dry when it's thick. The dry mix works a lot better for thick applications and comes in various setting times.
Third, make sure to have a lamp that can be moved so you cab shine the light on the wall in a variety of directions. It will let you see imperfections that can show up after the paint is on and the furniture is in.
I did the upper unit in my duplex and found out the hard way that putting it on thick and sanding the high areas off (a la Hometime, etc) is the wrong way. I took out a wall and added a beam, moved a doorway back and repaired every corner, wall/ceiling joint and all of the cracks from the tops of the doors and windows up and down in the place. 5 years and I have 3 cracks that came back and one of the previous owners removed a support wall in the basement, which caused the cracks. Oh yeah, when I noticed that the kitchen and one bedroom ceilings had joists that were bowed, I decided to remove the center of the ceiling and raise it (in the kitchen) and cut the bad joists so new ones could be sistered and rescrew the plaster/rocklathe to all of the joists, then skim and re-rock the ceiling (in the bedroom). New metal corner bead in all corners and along the ceiling/walls to straighten the bad curves, using dry mix, then lightweight from the bucket. The corners are all straight and crisp (better than I had hoped, considering my previous experience- and I'm really too picky about it).
A friend came over and set me straight by telling me that 3 coats and out is the best way. If the joints are uneven, use the dry mix and mesh tape to make it even and the compound from the bucket for topping it off. For the last two coats, put it on thin, let it set up a bit and skim it off so it's smooth. If it pulls, spray some water on it, because it set too much and then smooth it. If there are little ridges, they can be scraped off before the second coat of topping. The last coat goes on thin and you don't wait too long before skimming it off.
The biggest thing to remember is NOT TO TRY TO COVER TOO MUCH AREA AT ONE TIME. If you do, it will dry too much to skim it off and it'll be a PITA. With the last 2 coats being thin, there isn't much sanding needed and you won't end up with 6 buckets of mud in dust piles on the floor, like mine. It also saved a lot of time by using thin coats.
It may be annoying to have to take the drywall down and mess around with shimming it before putting it back up but the end result will be so much better I couldn't possibly put it into words. My place had 46 years of paint over the old plaster and there were a lot of areas of transition between the new mud and old plaster texture, so I sprayed texture on everything. The 2 areas I didn't spray are the new ceilings in the kitchen and bedroom because they turned out so well.
If you have large surfaces to make even, there is a float called a Darby that is used for this.
BTW, the bubbles are usually from moving the knife too fast over the mud. It's called 'cratering' and if it's in the final coat, will make an otherwise nice job look like garbage. Take a little extra time and get it smooth before moving to the next area. It'll be a pain to do this but when you look at it later and you did a great job, you'll be very happy. The great thing about drywall mud is that you can redo what looks bad.
what about D-mix ??? that stuff is the "miracle" cure
Right cure, wrong disease. The patient will still die.It is for covering small cracks and imperfections.
.....dammit Jim..........!
Use a straight edge of appropriate length to span the "dent" and mark the margins of the dent in at least eight places (more is better). The idea is to bring that area flush with the surrounding surface. Otherwise it is easy to overfill and end up "chasing a wave" down the hall.
First coat, Durobond or EZ Sand to fill the deepest 50% of the deficit. Second coat, Durobond or EZ Sand to cover and fill the next 40% of the deficit. Stay inside the marks.
Check with your straightedge once more to be sure you remain at least 1/16" below "flush"
Third coat, skim with EZ sand or drywall mud. Check with straight edge again. Sand or fill as required.
[edit] PS forget about the spray foam- to paraphase some football coach, "only three results are possible and two of them are bad".
The awful thing is that beauty is mysterious as well as terrible. God and the devil are fighting there, and the battlefield is the heart of man.
- Fyodor Dostoyevski
Edited 2/25/2006 6:17 pm ET by FNbenthayer
best way as prevously mentioned is to pull off the drywall, fair out the furring plumb, then redo the joints/mud - having said that, if it's a hallway in an old house, maybe leave "well enough" alone rather than investing more time and energy to get a less than "perfect" result - the other thing is to redo the wall with blueboard (3/8?) and then skim coat veneer plaster, the veneer can be adjusted to make up for the lack of plumb
Thanks everyone for all of the information. I know when I post questions like this that I will get varied answers. Regardless of which direction I end up going in, depending on how noticable I feel it really is, it is always good to hear from the pros and learn what they would do in these instances.
Edited 2/26/2006 9:13 pm ET by xosder11
BTW, I just tried out the D-MIX (do a search here for it). Nice to be able to skim and prime in one step.Rebuilding my home in Cypress, CA
Also a CRX fanatic!
MMMMM more tools. take a look around at this site for straight edges and such, for Ideas how you lay some goop on and float it nice and straight.
http://www.marshalltown.com/catalog/display_item.asp?edino=15756
I read through the other responses and I think there is a lot of useful information in their comments. I do a considerable amount of boarding and taping and have encountered similar problems to yours.
Here is how I would approach the problem:
First, if you can remove the wallboard and shim then that is probably the quickest.
Second. if you cannot remove the board, I would get a straight edge that spans the depression and would:
a) use quickset filler to fill the bulk of the depression. This fillers chemically hardens and sets up in 30 minutes to an hour. Use the straightedge to monitor your filling and also to screed off any high spots.
b) Next, I would take regular general purpose mud (because it has more adhesive than does finishing mud), thin it to the consistency of smooth peanut butter or thick cake batter and apply that over the quickset after it has set up. This layer of mud can be applied with a rectangular trowel. Again, use the straight edge to guide the application of the mud. Smooth the mud as best you can with the trowel and let it dry.
c) Sand the area using a pole sander or a hand sander with 120 grit sandpaper. If you were careful in spreading the mud it should already be fairly smooth and just need the high spots taken off.
d) Using a strong light or the straight edge identify any hollows and fill these with another coat of mud (if you thin the mud a little here it can make the job easier). You can continue to use a masons trowel, or can use a 8 - 10 inch taper's knife. Let the mud dry.
e) do your final sanding with 120 sandpaper, prime the walls, touch up any pits and apply your finish colour.
Regarding your second question pertaining to pits in drywall mud. I still get these on some jobs and believe they come from:
a) mixing the mud too fast and whipping air into the mix.
b) not periodically remixing the mud, especially if it has sat for several days.
c) applying the mud too fast, or with a wide drywall knife.
d) when trying to blend new drywall with previously painted surfaces this often causes pitting.
To fix pitting, all I ever do is:
a) once I have the second coat of mud applied and have sanded it, I use a small trowel and work mud into the pits - this usually fixes 85 % of them.
b) for the few that remain, I prime the wall and then either spackle the pits or work more mud into them. This usually gets the remaining 15%. Once the touch ups are complete I sand them and reprime the areas. Finish paint follows.
In my recent reply I made an error in the last part of the note where I indicated how to fix pits in the drywall mud.
Correction:
Step a)i after fixing the 85% of the pits, apply the finish coat of mud, sand and then prime.
Hope this all helps.
Thanks for the help. I will end up trying to fill the depression, because I have glued the #### out of the drywayy and the furring strips. I would agree with the majority of posters that shimming is the easiest option, but then again the brick is so sloppy that I think I would spend quite a bit of time scratching my head on that one as well."Oh, this is the worst-looking hat I ever saw. What, when you buy a hat like this I bet you get a free bowl of soup, huh? Oh, it looks good on you though."