sunken dry wall query

[dilbert firestorm]

it was something we didn't notice unfortunately.

recently we had a granite counter top installed in the kitchen. In the process, we noticed that at one section of the counter top, there was a large gap between the back splash and the wall. We called the granite installer to come back and take a look if they could fix the sealant better. They said they couldn't fix it because the wall was crooked. When we looked at it that section of the wall once more, we noticed that part of the wall had a shallow dent that covered most the section (about

1.5 feet). We think that the coffee maker that used to be on that section may have been responsible for the dent as the steam really had no place to go, the cabinet is also at that location.

would plaster smooth it out or get a new drywall? I'm think there might be problems with the granite counter top already in place.

[hrhofmann]

Build the low wall up with repeated coats of drywall mud. Mix a little (1 to 50 ratio) white glue with the mud until you have built up most of the lowness. Use a fan blowing on the wall to speed up drying. Be sure each layer is fully dry before adding the next coat. Then use straight mud for the final coats. Use a wide - 12" - trowell to apply the mud to get a smooth coating.

[RicodJour]

What's the point of adding the glue? You can build up compound without additional adhesive, no problems.

R

[Colbyt]

Place a straight edge on the wall horizontally. Mark the left and right where it touches, identify the center point, Make light vertical pencil lines at the 3 marks so that you do not create more work for yourself. Use a 4 or 6" knife to apply a vertical coat to the center line, size varies depending on the actual depth. Repeat as needed until the straight edge touches at all 3 points Feather in the left and right sides until the wall looks and feels smooth.

Take your time, more coats are less work and less mess than having to sand. Using a setting type 45 minute mud you should be able to do all coats in one day, lightly sand and paint the next though waiting a few days to paint is always better.

[RicodJour]

Why use little knives to fill in a bigger depression? Since the waviness in a wall is almost always due to the studs not being in alignment, I've found that using a larger trowel or longer straightedge to bridge between the protruding studs works the best. Simplest way I've found to do it is to overfill the depressions and use a 4' aluminum saw guide to strike off the excess compound. I agree with using setting type compound, but make sure it's sandable.

R

[hrhofmann]

I just feel better about the life of the patching. If there is a large build-up of mud and large variations in temperature and humidity, as is common in most kitchens, there is less chance of the patch cracking.

[Colbyt]

Why use little knives to fill in a bigger depression? Since the waviness in a wall is almost always due to the studs not being in alignment, I've found that using a larger trowel or longer straightedge to bridge between the protruding studs works the best. Simplest way I've found to do it is to overfill the depressions and use a 4' aluminum saw guide to strike off the excess compound. I agree with using setting type compound, but make sure it's sandable.

R

---------- reply---------------

Thank you for mentioning sandable. That was an omission on my part.

The reply was geared toward the perceived experience level of the poster with the goal of minimizing the sanding. Grossly overfilling or putting mud past the left and right high points will just make the wall more wavy. For a newbie trying to do it all in one or two passes will end up with 2 gallons on the wall and 1.5 of that sanded off.

The actual knife choices I would use would depend on the center depth and the arc of the depression but how do you communicate that much information when you do not have any details and have not seen the problem first hand. Except for bedding tape I use a 6" for most every thing.

[RicodJour]

Particularly important with setting type compounds as they can be a lot harder when dry and essentially impossible to sand.

With a long straightedge bridging between the high points, and keeping the straightedge at a fairly steep angle without applying too much pressure, it's easy to get the valleys filled in quickly and relatively smoothly. After that there's usually only a little top coating to do. I'd think that would be easier for a beginner, as long as the emphasis is on not leaving too much on the wall.

Different strokes. I have 1", 1.5", 2", 3", 4", 5", 6", 8", 10", 12" knives (yikes! I'm a drywall knife hoarder!) and use mason's trowels to go up ~16". I don't sand, I wet sand, and only do a little bit of that. I don't like the dust.

R

[RicodJour]

Belt and suspenders, Bob. If I'm building up a bit I use setting type compound as it doesn't crack hardly at all, you can put on a lot more a lot more quickly, and you don't have to wait for ages for the stuff to dry. If you're willing to take your time and put on a number of thinner coats of regular compound, that too will be just fine without any additives. The stuff sticks to glass, right? Once the wall is painted changes in temperature and humidity will have little effect on the compound under the paint.

The glue additive can't hurt, but it's not essential.

R

[Michael Dobony]

Fill too much and you will end up with cracks. If there is that much of a gap you will need to use drywall tape to cover and fill.

[dilbert firestorm]

[dilbert firestorm]

thanx all on the info that the drywall dent is fixable.