Understanding Drywall Ceiling Seam Humps

When it comes to interior drywall construction, achieving a flat flawless finish is crucial for aesthetic appeal. One common issue that homeowners face is the appearance of humps along drywall ceiling seams. These imperfections, often likened to speed bumps, humps, or shadow lines, can disrupt the visual flow of a room. Understanding how to fix drywall ceiling seam humps is essential to restoring the integrity of your ceilings.

Identifying the Cause of Drywall Joints Not Being Flat

Before you can effectively address the issue, you must identify what has caused your drywall joints to be anything but flat. Common causes include the finisher leaving too much joint compound over the seams. Occasionally it is caused by uneven framing. It’s important to take a closer look and assess the situation prior to beginning any repair work. Take a straight edge and place it over the seams. If the straight edge rocks like a seesaw then the finisher likely applied too much joint compound to the seams.

Step-by-Step Guide to Fixing Drywall Ceiling Seam Humps

Once you've pinpointed the cause, you can follow these steps to correct the problem:

1. Gather Your Tools: You’ll need drywall compound, a utility knife, sandpaper or an electric sander, a putty knife,drywall paper tape, mud pan and a 10 or 12 inch drywall taping knife.
2. Remove loose Paint or Texture: Start by scraping off any loose paint or texture that may be hindering your ability to see the seam. This will give you a better idea of the extent of the humps.
3. Apply Joint Compound: Use your taping knife to apply a layer of joint compound on both sides of the hump. Leave it on thick enough for the first coats to make the sudden ramp into a gradual change. Repeat coating both sides until a flat edge doesn't rock when placed over the seam.
4. Sand Smooth: Once the joint compound has fully dried, lightly sand it down with fine-grit sandpaper until it’s smooth. Be sure to blend it well with the adjacent surface to eliminate any visibility of the seam.
5. Finish Up: After achieving a smooth finish, paint the ceiling with flat ceiling paint. Any sheen in the ceiling paint will make the problem more visible. This will help in making the repair less noticeable.

Addressing drywall seams that are not flat may seem daunting, but with methodical steps and the right tools, you can eliminate those unsightly speed bumps. Remember that patience is key; rushing the process can lead to incomplete repairs. As you work, take your time to blend the repairs as closely as possible to the original ceiling.

Dimples in the Ceiling:

If you look at your ceiling when the sun hits it at a sharp angle, you might notice small, circular bumps or shallow craters. These are dimples. They usually show up in a straight line across your ceiling. Most people assume their house has a structural problem, but the reality is much simpler and less expensive.

What Is a Ceiling Dimple?

In the drywall trade, we call these screw pops. They happen when the wood is installed wet and once it dries out a space is left between the drywall and stud. When the drywall is pressed on or bumped, it moves back against the stud but the screw didn't shrink so it  pushes the compound that covers it out. This shows up as that small circular mark outlining the head of the screw. 

Why It Happens in Western Mass

Wet lumber and our New England weather. When wood studs and joist are not dried enough it eventually dries out and shrinks after the drywall is installed. Humid and damp weather can also cause the wood to take on moisture and swell. When the wood eventually shrinks a gap is left between the drywall and the wood.

Why You Shouldn't Just Mud Over Them

If you just slap some spackle over a screw pop dimple, it will come back in a few months. You haven't fixed the screw. The movement will just push the new mud right out of the hole.

To fix it correctly, we take these steps:

• Drive a new screw an inch or two away from the pop to secure the rock.
• Remove the loose material and reset the old screw.
• Apply multiple thin coats of joint compound.
• Sand and paint the area so it matches the rest of the ceiling.

Stop Chasing Shadows

Dimples are a nuisance that make a high-quality room look sloppy. If you have a ceiling that looks like a golf ball, give MrWalls a call. We will secure the drywall and make those spots disappear so you can stop staring at them.

Are the dimples in your ceiling appearing in a straight line or are they scattered?

In conclusion, by understanding the causes of drywall ceiling seam humps and following a careful approach to repair them, you can restore the beauty of your ceilings and create a polished finish in your home. Regular maintenance and inspections can help preempt these issues, ensuring your ceilings remain smooth and appealing for years to come. Check out our table below with the reason for drywall seam problems, and the solution.
MrWalls Repairs Bad Seams 

Reason and Solution table for Bad drywall seams