How long does it take to get moisture out of walls?

Author: Prof. Dorian Smith IV  |  Last update: Saturday, July 19, 2025

The time it takes to dry walls from water damage varies. It depends on how bad the damage is, what materials are affected, and how you fix it. Knowing these things is key to dealing with water damage well. Normally, drying walls can take three to five days.

How long can moisture stay in walls?

You have around 72 hours to complete the necessary cleanup after water damage to your property to stop mold growth. Then, incredibly harmful wood rot and mold can establish themselves on your floors and walls.

How do you get moisture out of walls?

A Guide on How to Dry Damp Walls?
  1. Initial Assessment. First, identify the source of dampness. ...
  2. Ventilation. Improving air circulation is critical. ...
  3. Heating. ...
  4. Dehumidifiers. ...
  5. Repair Works. ...
  6. Drying Out. ...
  7. Salts Treatment. ...
  8. Repainting and Redecorating.

What draws moisture out of walls?

Use fans to move air around the damp walls. Also use dehumidifiers, which can help remove moisture from the air and walls. Professionals use tools like moisture meters, infrared imaging devices, dehumidifiers and heavy-duty fans. That ensures the walls are truly dry before further repair, painting or refinishing.

How long does it take to fix damp walls?

Rising damp affected walls can take up to 6 months to dry out for a 150mm thick wall and will even take longer for thicker walls. The general rule is that it will take one month for each 25mm thickness of wall to dry after the rising damp has been stopped.

How to Find and Fix Your Damp Problems

How do I permanently fix damp walls?

How to repair a damp internal wall
  1. Locate the cause of your damp walls and fix this before continuing.
  2. Buy or hire a dehumidifier to completely dry out the room. ...
  3. Use a stain blocker to prevent future staining.
  4. Replaster your walls.
  5. Redecorate using paint, tiles or wallpaper.

How long does it take for mold to grow in wet walls?

mildew and mold will develop within 24-48 hours of water exposure. Even worse, it will continue to grow until steps are taken to eliminate the source of moisture, and effectively deal with the mold problem.

Will mold always grow on wet drywall?

No mold doesn't always grow after a leak. If the temperature isn't right or if the leak is properly dealt with quickly, there's a chance that mold spores won't be able to take root or grow.

How long does an internal wall take to dry?

Brace yourself; this is where we crunch some numbers. Just like baking a cake, the 'drying time' can vary based on the ingredients involved. Depending on the severity of the damp and the type of wall, it could take anywhere from a couple of weeks to a few months for the wall to fully dry out.

Can moisture in walls be fixed?

Exterior waterproofing coats can be applied to the exterior walls to stop water from penetrating the walls. The barrier that a waterproof coat will create will insulate walls and keep out rain and moisture, keeping walls from becoming damp. You can treat dampness in the interior walls by waterproofing the roof.

How to get rid of moisture behind drywall?

The best way to dry wet drywall is to dry it from the inside out. This can be done by using a fan or a dehumidifier. Use a moisture meter to check the moisture levels. Once you have started drying the drywall, checking the moisture levels with a moisture meter is important.

How much does it cost to fix a water damage wall?

Water damage restoration costs can vary widely depending on several factors, including the extent of the damage, the type of water involved, the area affected, and the materials and labor required for restoration. On average, water damage restoration in 2024 can range from $1,200 to $5,000 in the CA, USA.

Will a dehumidifier remove damp from walls?

Dehumidifiers can indeed aid in drying wet walls. After a flood, leak, or a spell of extreme humidity, damp walls can develop. A dehumidifier removes extra moisture from the air, lowers the humidity, and stimulates evaporation.

How to dry out damp walls fast?

To dry out small spots, place a fan in front of the damp area and turn it on high. For larger spots, install a heavy-duty dehumidifier in the room to suck the water vapor out. If you need to dry out a wall in an enclosed area, place moisture absorbent materials like dehumidifier packs near the damp spots.

How long does it take to get moisture out of a room?

Water damage can stem from severe weather, leaks, or burst pipes. Drying a flooded room typically takes around 72 hours under optimal conditions. The drying process depends on factors like room size, water volume, and material type.

How do you tell if there is moisture behind a wall?

Moisture and water that get behind the wall cause the backside of the drywall to soften and even become mushy. Look for soft spots or wet spots in the drywall and gently press into them. If the drywall depresses, there is most likely water damage. Mold on your walls' surfaces.

How long does it take for dry wall to dry?

Regularly check the dehumidifier's collection well, and reposition the air movers as necessary throughout the process to be sure to get everything. Use your moisture meter to track your progress. It takes around 3-5 days to completely dry wet drywall, so patience is key, but you should be seeing consistent progress.

What is the best way to treat damp walls internally?

How to Treat Damp On Internal Walls
  1. Improving the ventilation e.g. add kitchen and bathroom fans where necessary. ...
  2. Use a Condensation Mould Kit to remove any mould from walls and surfaces. ...
  3. Improve the heating of the property and insulate the cold walls.

How long does moisture stay in walls?

One of the most common questions we get asked about wet walls is how long they will take to dry out. There is no hard and fast answer because it depends wholly on the extent of the damage and the wall itself, as well as the core issue. It could take a few days, or it could take a few weeks.

How do you know if mold is behind drywall?

Your sense of smell is the first line of defense against mold. You can often smell mold before you can see it. If you notice a musty smell in your home, there's a good chance you have mold. If you think you have a mold problem, get on your hands and knees and smell the electrical outlets.

Do I need to replace drywall if it gets wet?

Extent of Water Exposure

Minor exposure can be remedied through proper drying techniques. However, if the drywall has been soaked or submerged, especially for a prolonged period, replacement is often the best option. Prolonged water exposure can weaken the structural integrity of the drywall.

How long can a wall be wet before mold?

Given the proper conditions, mold will start to germinate and grow as early as 24 hours after encountering the moisture source. In 3 to 12 days, the mold spores will colonize. In 18-21 days, the mold can become visible. In general, the longer that moisture is present, the greater the chance for mold to grow and spread.

What are the 10 warning signs of mold toxicity?

Although symptoms can vary, the most common symptoms seen in people exposed to mold indoors include:
  • Nasal and sinus congestion.
  • Eye irritation, such as itchy, red, watery eyes.
  • Wheezing and difficulty breathing.
  • Cough.
  • Throat irritation.
  • Skin irritation, such as a rash.
  • Headache.

Will mold stop growing if moisture is removed?

The mold spores will not grow if moisture is not present. Indoor mold growth can and should be prevented or controlled by controlling moisture indoors. If there is mold growth in your home, you must clean up the mold and fix the water problem.

Will wet drywall always mold?

Yes, mold will likely grow after a leak if no action is taken. The best way to prevent the mold growth is to stop leaks immediately. If you notice any water leaks, it needs to be stopped quickly and properly dried out.

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