How to Repair Cracks in Plaster Walls | Ask This Old House

[Music] hey maro kevin look at you with your cracked wall you know i often wonder were you painters whether you spend more time painting or fixing cracks because you're fixing these things all the time a lot of times i would say 50 50. my painting's only good if i fix the cracks yeah right for instance when you can see here a crack goes right from top to bottom yeah all right so do you see them in typical places that repeat or are they sort of just varied and all over there's three places that more likely you see cracks on a house it doesn't matter it's old or new if you have a door right up above the door jamb you'll see a crack starter from the ceiling all the way down to the trim toward the door trim or if you have a window same situation same way start up on the ceiling ends up right there on the top of the trim and the third place and the third place will be at the drywall plaster joint when you see a straight line with the crack that's the the drywall joint so two drywall boards come together it's at the scene and i mean obviously every house is moving old or new they're settling and that's sort of what's causing the crash absolutely the house settles all the times and all the material behind the walls behind the plastic is constantly contract and expands and that's what causes the crack shows up right at the plastic walls so let's talk about your technique for patching a crack and why do you have two here just to all right for a gap this big is we're going to use a traditional joint compound okay well we're gonna clean the cracks really well make sure there's no debris in there put a light coat on filled in really good and then we're gonna add a piece of mesh tape right right and then on top of it we're going to run another pass of joint compound so a little extra support from the mesh tape and when you say a crack is this big in your eyes that's a that's a pretty big crack it's more than i thought it would be yeah so you're going to use something with reinforcement that reinforced because that tape will also flags a little bit yeah it might not happen too soon the crack to come back so would you do a different technique for a smaller class absolutely for this one over here i like to use the elasto patch because this can go up to a quarter of an inch gap right and i like this the best because it contracts and expands like all the other materials behind the plaster walls and the good thing about is not sandable not so this is more flexible there's more flex contracting expense like everything else gotcha all right well let's see your stuff let's do this you can just write down like just around a little boat let's make sure that we press that with a little pressure to fill and go right in there just like that first pass is done now we're going to run the mesh tape right on top of that through a little pressure right there so you're kind of setting it in a real thin bed of the patch even though the mesh tape's got a little adhesive on the back yes kevin we cut at the bottom now it's time for as a second patch it does put a little bit on my body knife start from the top again just make sure i don't want to cover the mesh step the best again there we go it takes about 45 minutes to an hour to dry we'll come back we lightly sand we might add another coat just to make sure this is nice and smooth so let's see your technique with the flexible stuff completely different sort of look and consistency right there yeah you can see it that looks like a liquid caulking right there yeah looks like fluff another right going to add something to the putty knife again and we're going to work the same way we're going to make sure that goes right in there pressing it right into the crack i could have filled in really well from the bottom now did you say you don't like the sandness or you can't sand it you can sand this is this is not meant to be sand this is not meant to be sanded it's going to dry it's going to take about two hours to dry we'll come back we'll put the second pass on we make sure that's nice and smooth so now we wait no away coffee feels good [Music] all dry mara what do you think all right couple pads are completely dry now we're gonna just run a light sanding and then uh we're gonna clean up with that cloth and then we'll be ready to paint sand this no need to sand this forget about this one here no it's not centered about this one it is what are you using for grit we're going to use a 220 grit paper i'm going to do it by hand because just the small spot it's just like a circle of movement just like that the edges a little bit a couple trial marks in the middle but not too much work not a lot i think that looks good attack clot let's clean up some of this dust off there you go that's looking pretty good may i sure oh yeah nice yeah absolutely all right let's paint start with this brush two and a half angle cut do a little cut in here at the bottom and also in there a little there time to roll give it a try no you got it you're good never get in the way of a good painter all right so let me come at it at an angle because that's where it really reveals itself you'd never know those cracks are back there perfectly smooth nice job good i like it all right maro good information thank you thank you thanks for watching this whole house has got a video for just about every home improvement project so be sure to check out the others and if you like what you see click on the subscribe button make sure that you get our newest videos right in your feed

Channel: This Old House

Views: 199,660

Keywords: This Old House, DIY, Construction, Home Improvement, Ask This Old House, Building, plaster, walls, painting, Mauro Henrique, Kevin O'Connor

Id: ncD8StDldO8

Length: 7min 6sec (426 seconds)

Published: Sat Jan 15 2022