Why do doors sag?

Hi, this is a 2 part question.

1) Why do doors sag? Does it happen if you slam the door too hard?

I ask this because my bedroom door on the third floor of the house has sagged to the point where the latch no longer locks in with my strike plate. Therefore, when I simply pull on the handle without pressing down on the level, the door opens.

By "sag" I mean, horizontally the door width tapers (meaning it gets wider toward the latch) and vertically the door height tapers (meaning it gets wider towards the floor).

I watched a video online that recommended cutting a few pieces of thin cardboard to use as shims. I just tried this and it works! However I am not sure this is the correct remedy and will last long term. The cardboard also resulted in the hinges sticking out so that the hinges no longer fit snugly into the countersunk hole.

2) What is the proper way to fix a sagging door?


Thanks in advance for your input.

 

Welcome to the forums! Heavier doors, such as entry doors have that problem if the installer fails to remove inside screws on the top hinge and drive 3" screws into the hinge and the framing behind the door casing. On bedroom doors, which I assume are lighter, you may have that happening OR a settling issue. Is only one door doing it? Try the hinge screw thingy to see if it will correct itself first.

 

Thanks for the reply chandler!

This is a typical light bedroom door. Most of the doors on this floor do not have this issue.

Can I ask what does settling mean? Why does the top hinge need 3-inch screws?

 

On heavier entry doors the weight is borne by the hinge screws. Ever pull out a hinge screw??? They only penetrate the door frame. The door can tend to sag under its own weight if not given some assistance. Most new entrance doors will come without two screws in the top hinge. It is where the installer should install the 3" screw so the screw will not only penetrate the door casing, but go all the way into the framing of the house and hold tight preventing sag.

Now, as to your situation, do you notice any sheetrock cracks above this door? Hopefully not. It could be worn hinge screws or loose screws allowing the door to sag. Open the door and tighten the screws first to see if that helps. If not try the longer screw trick to see if it will bring it back in line. Let us know.

 

The sagging top hinge is the most common problem but a couple other things can happen too...

If the floor shifts out of level, it will affect the operation of the door. If the hinge side of the door opening sinks (straight down) that would also cause the door to have a wider gap on the top of the latch side.

Chandler described what can happen if the top hinge pulls away from the stud. Something similar can happen to the bottom hinge if the door is not shimmed well. The same forces that pull the top hinge out can push the bottom hinge in slightly.

It's hard to say what the correct fix would be without being there and actually measuring the opening to see if the sides are still parallel (a 32" doorway would measure 32" at all points of the jamb- across the top, middle and bottom) and whether the head is still level. But you usually can't go wrong putting the long screw in the top hinge / stud to see if it pulls the door back up.

 

I see no cracks around the door.

The house is about 21 years old. I get the point of the 3-inch screw now. What I don't get is why on Earth the builder didn't use them?


Here's some more info on the doors on this floor:

There is another identical door to the right of the main door(if we're in the interior); the jambs of the 2 doors are only 4 inches apart. This door goes to the bathroom. The hinges of the bathroom door are on the bathroom side, but like the main door, it horizontally increases in width to the latch side, and vertically increases width to the floor.

If I'm facing these two doors from the inside, on my right there is a third identical door, which is a closet. The diagonal distance between the bathroom door jamb and the closet door jamb is 14 inches. This door also has the exact same issue as the main door and the bathroom door (wider on latch side, wider towards floor).

None of the 3 doors in my bedroom latch, with the worst offender being the bathroom door and the best latcher being the bedroom door.

I set a level on top of the door frames of these 3 doors, and all of them are perfectly level.

Regarding the rest of the doors on this floor outside of my bedroom, 11 of 11 latch.



This is why I originally asked if the sagging could occur from slamming the door. My bedroom is probably the only one with repeatedly slammed doors. I know correlation is not causation, but it seems like such a reasonable explanation!

 

Using the doors can cause hinge screws to loosen, or as Brant mentioned, the door casings could be moving inordinately due to poor shimming, and/or lack of fasteners through the shims and the shims slipped. It happens in fast paced door installation by rookies. They only nail the clamshell trim and not the casing. With your level, check the plumb on the hinge side casing.

 

I was at a remodelling convention in Las Vegas once, and a very well known California trim carpenter (that has articles published in many magazines) was showing a few "production methods" to speed up the work. One of the methods he showed was to simply nail the casing to one side of the door and then use that as a sort of "nailing fin" to shoot the jamb into the opening. He then cased the other side. No shims.

It was certainly fast, but that sort of mentality can also be why doors later sag, and why 3" screws aren't used more often.

 

Ya, I've painted behind a few 'carpenters' that used the casing to hold the prehung door in place those were usually the houses were the builder had to pay me to go back and caulk/paint the door jambs/casings after they were repaired under the 1 yr warranty.

 

"...then use that as a sort of "nailing fin" to shoot the jamb into the opening."

I've seen more than a few (and heard of many more) exterior doors that were only attached by finish nails through the brickmold and interior casing. Several could be removed by just grabbing and pulling.

How much longer does it really take to install some shims and a few deck screws through the jamb? 10 min?

 

I use long trim head screws behind the rubber seal, so they never show.

 

Being on the third floor, you can expect some movement of the floors and other things.

Wood shrinks with time and newer wood will shrink more. Also, beams sag/settle due to shrinkage and to "creep" from long term loads.

It is common for the sag to create an opening the becomes wider at the bottom than the top. On very old buildings, I have seen sags that created a gap between the baseboard that you could see light through because the wall shrinks less vertically than the supporting beams below. Wood shrinks much differently in different directions (laterally and longitudinal).

Dick

 

OK, I'm a naildriver by trade, so when I am at a doctor's office, etc. I look around and notice things. Today we were at wifey's orthopedic surgeon's office waiting to be seen in a room and I noticed something related to this thread. Note how low the striker is hitting on the plate? Note also how the hinge is pulled away from the casing. That is typical of constant use of a door with short screws pulling out of casing.

 

As you can probably tell, I am very unknowledgeable and unhandy (believe it or not, i've never even used an electric screwdriver before).

I watched this video:
How to Repair a Skewed Door | Video | This Old House

I saw all Tom did was cut cardboard, a task so basic even I can do it. The cardboard shims did the trick and straightened out the door and the latch locks in with the strike plate. Is this an okay fix? am I just being paranoid?

 

If it works, then you did good. Well on your way to your degree in carpentry Only 500 more semester hours to go. Glad it worked out for you!

 

"Ignorance is bliss." Because of you all, I am slightly less ignorant and now slightly less blissful.

Those puny short screws better not cause any more trouble....


I think having the "handy" gene is something you've gotta be born with. I've seen handymen that can look at an issue and figure out the problem within seconds. I respect this type of aptitude a lot since I'm clueless.

I wish my high school had made shop class a requirement to graduate.