I remember Bob Vila on This Old Spouse learning how to apply a skimcoat to drywall. They covered the entire surface.
Tim “Ask The Builder” Carter shows a different approach. The joints were taped and mudded over, but the rest of the drywall was still bare. Then he used a primer specifically for sealing drywall.
When should drywall be completely covered with a skimcoat, and when do you seal it with drywall primer?
Edited 3/6/2008 1:40 pm by jyang949
Replies
If the drywall is in good shape, a good PVA primer will work or should you desire, one of the thicker "roll on" types of primers would be fine.
If the drywall has had something stripped from it...wallpaper, wood paneling, or has had a lot of repairs made to it where the wall is rough and patched, then a skim coat might be better.
It all depends on what you have now and what level finish you want in the end.
Mongo
The funny thing is, Vila was applying the skim coat to a new installation of drywall. He was trying to apply a perfectly smooth layer, so he wasn't going for a rough-textured surface.Which brings up another question: Assuming that the underlying drywall is undamaged, what gives the smoothest surface, a skim coat or drywall primer?
Were they doing skim coat plaster or a skim coat of joint compound?Plaster will give you the smoothest, veneer coats are put over blueboard.Skim coat joint compound can be done well, but it's really up to the person controlling the trowel. You can get as smooth a surface as the taped/mudded joints on regular drywall are, because it's the same type of material. But to get smooth smooth smooth requires sanding, and sanding joint compound generates a lot of dust.Typically sanded joint compound will give a smoother surface than drywall paper, as the paper can lend a bit of texture to the painted surface.So I'd say regarding an entire wall surface? Smoothest is veneer coat plaster. Second would be sanded skim coat joint compound. Third would be standard taped gypsum board with the joints sanded, then the entire surface primed and painted.
But to get smooth smooth smooth requires sanding
Not if you know what you're doing. A DW joint compound skim coat should need no sanding (just as good joints need hardly any).
Riversong HouseWright
Design * * Build * * Renovate * * ConsultSolar & Super-Insulated Healthy Homes
Mongo has it right in xxxx.4.
Skim coat yields a smoother finish to the wall / ceiling than just sanded joints and primed.
Be aware that this is not an either / or situation - a skimcoated wall still needs sealer / primer.
The home I am currently working in has plaster skimcoat over drywall -- then the walls were painted with flat latex paint applied with a 1/2" nap roller. The homeowner said the walls were too smooth. Go figure.
Jim
"Too smooth"? I live in Orange County, in a city that was incorporated in 1989. Seems as though every wall of every house is covered in orange peel. I'd much rather have smooth walls.
We've had both in my house. Skim coated plaster looks fantastic, in my opinion, but is something that must be left to the professionals. Drywall taping is something that can look good, even when done by DIY'ers.
>>Skim coated plaster...is something that must be left to the professionals. <<I believe it. Bob Vila couldn't do it anywhere near as well as the professional. There was something so cool the way the pro worked--poetry in motion.
The coolest thing is watching them do it on stilts.
Speaking of stilts: I walked on my first pair a couple nights ago in my dreams. I was awesome...I could run, jump and even do a sliding stop like the NHL players do on the ice! Bob's next test date: 12/10/07
Drywall taping is something that can look good, even when done by DIY'ers.
You must have some pretty skilled DIYers out your way.
DW finishing is the easiest thing to do poorly by the inexperienced (and the reason most carpenters won't touch it), and the easiest thing to do well by the skilled.
Riversong HouseWright
Design * * Build * * Renovate * * ConsultSolar & Super-Insulated Healthy Homes
So True! Also, from a time standpoint the drywall finishing only pros can speed through a job with little sanding and make it look easy. If you don't finish drywall all the time it's hard to even come close. Funny thing is I am 6'4" and most of the drywall finishers seem to be about 5'5". It's crazy watching them move on the stilts like it's second nature.I have seen a couple of subs use thinned joint compound and a paint roller to put a final skim coat on drywall. They follow up with a large flat tapping knife that looks like it is on a broom stick. End result look real good.I have had real good results using USG First Coat to finish unskimmed drywall before paint. Best sealer/last step product I have ever used on drywall.
I thought skim coating evened out the surface texture . That is ware the joints are taped and screw holes filled and sanded the texture is smoother than ware the paper has not been touched. Skim coating around here is done with a water down toping mix rolled on with a paint roller then using a wide tool. probably 3'wide skimmed off. The only job I let the drywall contractor talk me out of skim coating and using a special primer I got shadowing. That is vertical lines over the studs because the finisher usually hits all the screw holes with one vertical pass not each screw hole. It took me 5 or 6 coats of paint to even the texture out. The light just hit a few walls just right to show it. Now every drywall job is skim coated.
Have you ever had a home owner shine the walls after the drywall contractor is complete. I did. He had me go into the house at night when it is dark and used a flash light held at the bottom of the walls and shining up towards the ceiling. Show's everything that could ever be wrong with the job. To high of but joints really stand out. No Fun.
Have you ever had a home owner shine the walls after the drywall contractor is complete.
Since I almost always do my own DW hanging and finishing, I don't wait for the homeowner to turn on the lights.
I hold a 100W worklight in one hand and sanding pad in the other. I make sure everything's dead smooth before priming - and then go back with the mud after priming and touch up any defects I missed.
And, by the way, I've never seen a "professionally" done DW job that looked as good as what I do myself. They work by the square foot, I work by the hour and my reputation doesn't depend on the quality of the framing (which no one sees once it's closed in) but the quality of the finish.
Riversong HouseWright
Design * * Build * * Renovate * * ConsultSolar & Super-Insulated Healthy Homes
Edited 3/6/2008 9:07 pm ET by Riversong
I hold a 100W worklight in one hand and sanding pad in the other. I make sure everything's dead smooth before priming - and then go back with the mud after priming and touch up any defects I missed.
Sounds very familiar..... except I use a 150W light. I'll bet there is a pencil clamped in your teeth to circle defects. Piffin subscribes to the same technique.
The technique does require a bit of judgement - the light direction should be similar to the room light - shine the inspection light away from the windows for example - imitate / exaggerate the light that will be in the room.
I consider it a reputation builder when a homeowner wants to shine the walls - I have been there before him and I know what he will find!
Jim Never underestimate the value of a sharp pencil or good light.
Sanding?C'mon Robert, per your previous reply I thought sanding wasn't required for a smooth smooth smooth finish!<g>And I fully agree about who gets to finish the drywall. People go to great lengths to get a nice looking house, then decide to save a few dollars by doing the drywall mudding and taping themselves. Ugh.A couple of trades that I can pull up a lawn chair, sit down, and enjoy watching these people at work: Plasters, drywall finishers, and a good mason. I built my own house solo, the only things I subbed out was the poured foundation, the chimneys, and the drywall. A man's got to know his limitations, and those are mine.Best, Mongo
Too funny! I used to have people do that all the time and drive me nuts. Think about it, in the real world how often is the light going to hit the walls in that exact way... probably never. But from the homeowners standpoint I understand where they are coming from.I no longer have this problem any more. I usually explain to the homeowner the difference in the level of drywall finishes. Most finishes - at least by me - are level 4 no compound skim coat USG 1st Coat 2X. Then there is level 5 complete skim coat followed by USG 1st Coat 1X. I have a package of brochures from USG that explains the different level of drywall finishes in detail. I go over this with the homeowner during the bidding process. The level they choose is clearly stated on the contract. When I explain the real world difference between 4 and 5 and the added cost of level 5 most choose level 4. I have never had a homeowner regret going the level 4 route.
Nathar, I wish you hadn't made that observatio about leaving it to the professionals. That makes it an irresistable challenge.By the way, is skim coat just joint compound with more water?Janet
Edited 3/6/2008 8:57 pm by jyang949