Jim Rooney, On the Level columnist
Jim Rooney, On the Level columnist (Courtesy photo)

I want to paint the interior of my house this spring. I've noticed that there are several very obvious drywall nail pops, most frequently occurring where the ceiling meets the walls. Have you addressed this issue in the past?

Yes I have. Drywall nail pops are the bane of many homeowners and it depends upon when and how the house was built. Nail-pops have many causes but only two results. Either the nail moves and the drywall stays put and the nail "pops" creating the tell-tale dimple or the drywall moves and the nail stays put with similar results. If you do not understand which of the two is happening, you will not take the appropriate repair steps in paint preparation and you will have doomed your efforts — the nail will pop again.


When nail-pops happen on the ceiling of the floor just beneath the attic and near a wall intersection, the culprit is a phenomenon known as truss-uplift or a variation of it. It became apparent when we started building tight, well insulated homes in mixed climate conditions — climates with wet, cold winters and warm to hot, humid summers — using wood trusses for roof assemblies.

Homeowners began to complain about the appearance of nails backing out of the drywall especially near the intersection of walls, such as upper bedrooms, baths and hallways. We tried everything to get those nails to go back in and stay in. We used longer nails, fatter nails, glue-coated nails, nails with ring shanks, screws —you name it — but nothing really seemed to work. Finally somebody noticed that this type of nail-pop occurred in places where the drywall couldn't flex for a variety of reasons but the substrate upon which it was attached did, causing the nail to move and the drywall to pop.

What's happening with your ceiling is that the wood framing is moving somewhat in response to ambient outside humidity and is flexing and the drywall in those areas where the nails are popping can't — hence the popping.

What to do? Just pull the popping nail out and spackle over the hole and be done with it. It's obviously not holding anything as it has popped and the drywall isn't falling down. It sometimes takes some convincing for some that this will take care of the problem and they must be watched carefully so that they don't try to slip in another nail or screw nearby. It won't work.

Now, there is another sort of ceiling nail-pop that does need a nail or screw to fix it and that's easy enough to determine. It usually occurs out in the field of a ceiling drywall sheet and not near a wall. Place your hand or use a hammer handle or flashlight butt near the nail-pop and push up. If you see the dimple flex, then the drywall has separated from the substrate and the nail has lost its ability to hold and I recommend a drywall screw (inch and a quarter) be driven in about four inches away from the pop to pull the drywall back onto the stud or joist from which it has separated.

If you think about how drywall is traditionally nailed, you'll understand why these things happen. The drywall installer drives the nail in and the last smack of the hammer is to dimple the drywall at the nail-head so the spackle can cover the nail. The drywall hammer head is even shaped for this. Fine, but that last swat of the hammer has just fractured the gypsum of the drywall at the point of attachment weakening it, setting the stage for future problems. Old-timers used roofing nails and double nailed drywall in an attempt to reduce popping. That made more work for the finishers.

In the early 1970's the industry discovered drywall adhesive and glued drywall did very well. Later we discovered drywall screws that were developed to attach drywall to metal studs used mostly in commercial construction.

I recommend screws for all types of drywall installation. The better homebuilders are insisting that installers screw their drywall to prevent callbacks by nail-pop annoyed customers. Drywall screws have gained that mythological status enjoyed by only a few products such as construction adhesive, WD-40 and duct-tape and no repair inventory is complete without them.

Since your reason to repair the nail-pops now is to prepare for a paint job, the most humbling exercise you can do in drywall paint preparation is to take a strong light, flashlight or trouble-light, and, with it on, place it against the wall or ceiling allowing the light beam to wash down the surface. You will see every tiny blemish that exists on the surface in stark contrast. That's the bad news.

The good news is that the industry quality standard states that if the blemish is not visible under normal room lighting from a distance of six feet away, then the job is acceptable. Keep that in mind and don't drive yourself crazy trying to get the surface perfect. You never will.

And by the way, use a wide drywall knife to do the point up; those puny six-inch knives make a mess. Proper sanding technique is another prerequisite skill and the trick is not to raise a knap in the nearby paper. Some put the paint prime coat on, then resand the drywall. It's not easy but you'll learn.
