# Smoothing out ceiling butt joint



## Mike410 (Apr 15, 2014)

Hello,

In a couple places where drywall was joined together on the ceiling, there is a visible line, slight bulge. Is the best way to fix this, using joint compound to level over this to create a more even surface?

If so, do you need to prime the wall before mudding over existing paint?

Thanks


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## mark sr (Jun 13, 2017)

Joint compound will adhere to paint although it doesn't hurt to give the paint a quick scuff sand first. You need to float the joint out wider - that will make the 'hump' harder to spot. Make sure the drywall is well secured before you start - add screws if needed.


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## ryansdiydad (Aug 16, 2015)

Is there any significant texture on that ceiling? If so, be prepared for the newly and completely smooth joint compound to stand out a bit... people here can guide you on matching it up better if you need to...

I just did what you are doing on some walls.. like mark said the hump is still there it’s just invisible to the eye... don’t build up over the hump just taper it out more on either side of the peak there..


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## Bud9051 (Nov 11, 2015)

Take a 4' level or very straight piece of 2x4 and place it over that hump so you can see how much you have to add to each side. I suspect the problem originated with the initial tape job, too much mud over the tape, a very common issue. Once finished and taped, where you are, there is little that can be done about the thickness at that (those) joints. Avoid sanding as you would risk hitting the tape, which would require MORE mud to hide.

From what you see with the level across the joint you will get an idea how far out you will need to go to make the bump less noticeable. 

Note, it can be completely hidden but that would require floating virtually the entire wall.

As you work, keep checking with the level and don't try to do it all in one coat.

Bud


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## ClarenceBauer (Mar 4, 2005)

To feather out the high areas you should use a Magnesium Slicker it is 42 inches long it is used to straighten & slicking ceilings can also be used on walls.


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