If the door is sticking in several places, it could be swollen because of the humidity. This is likely to be the problem if your door sticks in summer, but is fine during the winter. If you have one, try running your air conditioner to get rid of the moisture in the air. Running a dehumidifier can help, too.
Humidity and Weather
Your doors may start sticking after heavy rain. The humidity and moisture in the air rise after a rainstorm, causing the wood in your home to swell. As the wood swells, your doors and windows will become harder to open and close.
The swelling is caused by humidity and temperature changes, which cause the wood to expand and contract. Over time, the door will adjust to the new conditions and return to its original shape.
If the swelling is due to humidity, using a fan or dehumidifier can help reduce the moisture and make it easier to open. Will a swollen door go back to normal? Sometimes, yes! If the humidity drops, a swollen door might shrink back to its original size.
If your home is particularly prone to humidity, investing in a dehumidifier can work wonders. A dehumidifier reduces the moisture in the air, making it harder for the timber to absorb water and swell. It's like putting your door on a moisture diet—less moisture means less swelling.
Don't seal warped doors, this will not allow the imbalance to correct itself. In most cases a warped door will straighten out after it has acclimated to its surroundings. We recommend the door be allowed to hang through at least a heating and cooling season to allow it to straighten out.
If you've noticed that you have sticking doors and windows in your home, it's likely a sign of larger, underlying foundation issues. Sticking doors and windows are some of the most common symptoms of foundation settlement, especially in the Southeast United States where humidity and rain cause many foundation issues.
The two primary reasons your doors and windows tend to stick in the summer is thermal expansion and humidity. Thermal expansion is the process where materials like wood, vinyl, and metal (common materials used for doors and windows) expand when they are heated and contract when they cool.
Identify the exact areas where the door sticks by marking with chalk or pencil. Use sandpaper for minor adjustments and a wood plane for larger corrections. Regularly maintain doors to prevent future sticking, including oiling hinges and checking for moisture damage.
Check Humidity Levels
Swollen wood is one of the most common causes of a sticking door, so as part of your initial inspection, check the humidity levels in your home with a hygrometer. If the reading is more than 70%, then humidity is likely the cause of the sticking door.
If you have wooden doors on your home, humidity can cause them to stick. The moisture in the air causes the wood to expand, making it harder for the door to fit into the door frame. If you notice your door stuck in the frame during humid months, moisture in the air is likely the source of the issue.
Use dehumidifiers and air conditioners, especially in hot, humid climates, to reduce moisture in the air, but be sure that the appliances themselves don't become sources of biological pollutants. Raise the temperature of cold surfaces where moisture condenses. Use insulation or storm windows.
Rubbing soap or wax on the sticking area will often help. Silicone spray lubricant, sold at most home centers and hardware stores, also can be used. Try shims. A thin filler or shim behind one of the hinges will often free a door that sticks near the top or bottom of the latch side.
The good news is that a sticking door is often easy to fix. Tightening the strike plate and hinges are reliable ways to fix a door that sticks. If that doesn't work, replacing the hinge screws with longer screws usually does the trick.
The best way to loosen a stiff stuck or broken door latch is to lubricate it. Before doing this you should completely remove the latch from the door first and check it for rust and other damage.
If you live in an area that is humid year-round, the door will swell. Even in 'dry' areas, if you tend to use the shower with the doors and windows shut, your bathroom could end up with a sticking door from the extra humidity in that room.
Timber tends to swell more with moisture (and some composite doors do contain timber), and humid weather can bring a double whammy of heat and ambient moisture to swell your doors with! Swelling in heat/humidity isn't anything you need to be worried about, as this is a natural process that affects these materials.
Basically to use a rasp, you simply place it on the surface you're wanting to reduce, and drag it across the wood. You need to apply pressure to the rasp so it digs into the wood as you slide it. There's really no way to mess this up.
Humidity is usually the culprit for sticky doors since high moisture levels cause the material to expand, pushing the door into the frame. This only happens in wooden doors, but steel and fibreglass doors tend to stick, too, if the wooden door frame swells.
Door Swelling
As we all know, excess moisture is wood's natural enemy and your wooden doors swell because it absorbs moisture that is present in the air. In the summer, it is not uncommon for doors to swell and start “sticking” as the humidity levels outside increase.
The Science Behind Door Swelling
During the winter months, the humidity levels inside homes tend to increase due to factors such as central heating, reduced ventilation, and moisture from cooking and showering. As the wood absorbs this excess moisture, it expands, causing the door to swell.