How to Remove Moisture from Walls (Complete Guide 2021)

Knowing how to remove moisture from a wall is the dream of every homeowner … And also of every architect (why deny it). It is incredible that moisture problems in walls are so common in homes, (whatever their age). What are we doing wrong?

If you take a few minutes, I promise to tell you how to remove moisture from the walls , and what matters the most: not only your symptoms, but also its causes, so that it does not reappear.

Causes of Moisture in Walls

There are 3 common causes that can cause moisture on the wall, depending on where the water comes from:

  • Humidity due to seepage caused by rain
  • Capillarity moisture (moisture that comes from the ground) generated by failures in foundation insulation
  • Condensation Humidity, caused by high levels of indoor ambient humidity

Believe me this: IDENTIFYING the source of moisture on the walls is half the battle won. Think about it a bit:

How to pretend that a doctor is right to cure a disease WITHOUT knowing its causes? This is more or less the same: the humidity in the wall is the DISEASE, the doctor is the ARCHITECT and the correct therapy is what we will see next.

Steps to Remove Moisture from Walls

The best way to remove moisture from the wall is to apply the corresponding techniques, according to where the water may come from. For example, an anti-humidity paint DOES NOT SOLVE the humidity of the foundations, but it IS EFFECTIVE when the humidity problems in the walls occur after a rainstorm. I insist on the importance of identifying the CAUSES so as not to waste your money on moisture treatments that do not work .

We will then see which solutions for damp walls are suitable.

# 1 Moisture from rainwater leaks

How to identify the seepage moisture? Basically because you will notice that the humidity problems on the walls are exacerbated after a rain. Knowing that this is the cause, let’s assume this reality:

The walls exposed to the outside SI or SI must have adequate insulation against climatic agents. There is no solution for humidity in walls if they are not waterproof. Let’s see then some ways to eliminate it:

✅ Anti-humidity Paints

Latex waterproofing paints are a good resource for sealing exterior walls. It penetrates the pores and microcracks of the plaster, making it water-repellent. In addition, as they have resins and rubbers, they have great elasticity that allows them to withstand continuous changes in temperature, without cracking.

If your walls have exposed bricks and do not have water-repellent (anti-humidity) render, you can use transparent silicone paints. They come in matte, semi-matte and glossy finishes, depending on the type of appearance you are looking for. The silicones generate the “skin effect”: rainwater does not penetrate the pores, but allows the wall to “breathe” and thus eliminate remaining moisture.

Waterproofing walls with paint is something you can do on your own! In this article I tell you how to paint exterior walls so that you can save good money.

✅ Water-repellent plaster

Waterproof plaster is the most effective solution to moisture on exterior walls. It is the first layer that must be done on the wall to protect it from the humidity of rainwater. No more than 5 to 7mm thick is required for the waterproof whipping to fulfill its function.

The “universal” ratio of waterproof plaster is: 1 part cement + 3 parts sand. The waterproof mix is ​​hydrated with water diluted with a waterproof additive that REMARKABLY improves the waterproofing capacity of the render. Did you know that the vast majority of people DO NOT perform this moisture-insulating layer well?

In this article I tell you how to make an EFFECTIVE waterproof plaster that will last over time. They are simple steps that will save you trouble for a lifetime.

# 2 Foundation Moisture

The origin of foundation moisture (capillary moisture) may be the lack of an insulating layer that blocks the rise of moisture that comes from the natural soil.

When the house is in direct contact with the ground, its walls absorb and pump water from the ground. The walls are impregnated with water due to its great absorption, and thus problems of humidity in the walls invariably arise.

How to differentiate foundation moisture from other types of moisture? The main characteristic of capillary humidity is that the walls with humidity are in the WHOLE house. It does not matter if they are indoor or outdoor. Moisture stains climb the walls from the ground to a height of no more than 1.50m.

How to solve humidity problems in walls with capillarity? I tell you what NOT to do and then yes, how to remove moisture from the walls, but this time permanently.

You should NOT paint the walls with humidity, or cover them with another material that covers them. The first would generate paint flakes and the second would only achieve “mask” it, but behind the wall the humidity would still be there.

Although in this article I tell you in detail how to solve moisture by capillarity , let’s see what are the best treatments for moisture in walls originating in the foundation:

✅ Redo the Isolating Layers

It is normally used in older houses, which generally DO NOT HAVE AN INSULATING LAYER, as an insulating barrier against the rise of humidity.

It consists of cutting from side to side the walls with humidity problems, above the level of floors or baseboards, at a height that is about 15cm from the floor. The treatment includes the replacement of that area of ​​the wall, by rows of brick glued with waterproof mortar. As a complement to ensure the moisture barrier, a plastic or asphalt membrane is placed. In this way, a hydraulic barrier is achieved that acts as an insulating layer, blocking the rise of humidity on the wall.

The cut of the walls is alternated, in widths of around 50 to 60cm, to avoid affecting the stability of the wall with humidity in question.

✅ Silicone Injection

The resin treatment consists of injecting the wall with a silicone-based waterproofing liquid . In the lower part of the affected walls, an anti-humidity barrier is formed that cuts the ascent of water through the capillaries of the wall in question.

To remove moisture from the wall with this system, holes are made in the lower part of the affected wall. The holes will have a diameter of 13mm, at a 45º angle, being made only on one of its faces. The product is poured into them until the wall is saturated. The process may need to be repeated for at least 48 to 72 hours.

In contact with moisture on the wall, the product polymerizes (hardens), forming an impermeable water-repellent barrier.

✅ Wireless Electroosmosis

Very often I am asked: I have moisture on the walls, what can I do? 

It may sound strange to you that I say that we will see how to remove moisture from the walls using “waves.” I assure you that this will be a case in which the “rare” is going to surprise you with its results. Undoubtedly, it is the best system to eliminate moisture by capillarity.

In simple terms, the wireless electro osmosis system consists of the use of a small electronic device (15x10x45c). It is connected to an electrical outlet in the house and to a javelin for grounding. The device emits frequency waves, which reverse the polarity between the walls and the ground, changing the direction of the water’s rise .

By means of this system, not only the humidity in the walls but also in the floors, descends towards the ground. The DRYING is gradual and definitive, managing to definitively solve the humidity of the foundations. If you are looking to know how to remove moisture from walls, this is your ideal solution .

# 3 Condensing Humidity

This type of humidity is produced by excess water vapor suspended in the air inside the house. When the ambient humidity percentage reaches 100%, it means that the air CANNOT admit more water in the vapor state. As a consequence of this, excess water is deposited on all cold surfaces in the house, generating moisture on the walls. Symptoms include damp glass and patches of moisture and mold.

How to remove moisture from condensing walls? There is only one effective way: REDUCE THE AMOUNT OF MOISTURE WE GENERATE.

This article explains in detail 20 SAFE ways to remove condensation moisture . Meanwhile let’s see the most effective actions to know how to remove moisture from walls.

✅ Do not dry clothes indoors

The water that the garments lose is transferred to the interiors . The ambient air becomes saturated with humidity, humidity is generated on walls by condensation, and also on floors and ceilings. The same happens when drying the bathroom towels that have just been used.

✅ Ventilate the Environments

Ventilating a room means opening THE WINDOW that communicates it with the outside. If this does not exist, place an AIR EXTRACTOR , which does it, artificially, but at least manages to eliminate humidity by condensation from the environment. They fulfill a fundamental mission: to eliminate the steam before it condenses on the walls of the house .

✅ Cover containers when cooking

The steam that is released from the containers when cooking is transmitted to the rest of the rooms, condensing on the rest of the walls of the house.

✅ Homemade Moisture Absorbers

There are products to remove moisture from the walls that can be made at home and many others that fulfill the same function and that are available on the market.

The former offer an ecological alternative to eliminate humidity by condensation in closets, closets for small rooms. To prepare your own home dehumidifier you can use household materials that have a natural power to absorb excess moisture, such as coarse salt; charcoal; chalks (chalk) or rice .

. You can also get a wide variety of products to absorb and eliminate ambient humidity without having to start making them. Although you have to renew them every so often, they last a long time and are cheap.

✅ Reduce the number of Indoor Plants

Indoor plants are very advantageous in many respects, but they also increase humidity by condensation . In a context of few plants clearly, perhaps we are not facing a fact of care. The outlook will be different if the house already has wall humidity problems with the presence of fungi. Plants favor the conditions in which these types of organisms proliferate.

✅ Improve the thermal insulation of the house

Perhaps it is one of the most effective weapons to remove moisture on the walls by condensation. Exterior walls with little thermal insulation cool down easily, favoring the excess of environmental humidity to condense on the interior face of the walls.

If the exterior walls are thin, they will suffer even more from this type of problem. It is very difficult to remove moisture from walls when they cool so easily. The ideal is to improve their insulation so that they do not get cold; if they don’t, the water vapor will not condense.

Only by improving the insulating capacity of the walls that face the exterior, will be able to solve most of the problems of all the walls with humidity, even the interior ones. For this you can resort to the use of mineral wool or fiberglass. Placed between the interior wall and plaster rock plates, it is possible to increase thermal insulation, sacrificing only about 4 to 5 cm from the environment. All this with almost no work and in a very short time.

For more tips on how to protect the house from the cold , I leave you this article so that you know how to permanently remove moisture from the walls due to excess condensation.

✅ Replace Heaters without external outlet

Almost everyone is unaware that this is one of the most important generating sources of water vapor, generating many of the problems of damp walls. Stoves with an open flame that do not ventilate to the outside , emit carbon dioxide into the room they heat. When it combines with the oxygen in the air, it transforms into water vapor, which then moistens the walls.

How to get moisture out of the wall? Without a doubt one of the most effective ways is to replace these heaters. I don’t intend that you change the entire heating system in your house, but a few minor actions will help.

For example, balanced draft heaters (with an outside outlet), DO NOT consume oxygen from the environment and DO NOT generate water vapor. They are a very good alternative to remove moisture from walls reducing the formation of stains and mold.

Devices to Eliminate Moisture at Home

A data of GREAT IMPORTANCE to reduce the problems of humidity at home. If the outlook of mold, moisture stains, condensation on windows, clothes that NEVER dries, looks familiar, this will help.

In these cases, it is most likely that the humidity in the house has to do with what is known as condensation humidity. In simple words: excess humidity,  typical of a climate that predisposes to SUFFER with these symptoms. And there everyone wonders, how to get moisture out of the wall when it is in the air we breathe?

For these cases there is a device that extracts water vapor from the interiors, returning dry air. These condensation removers are known as dehumidifiers .

In a very short period of time they reduce humidity levels, from almost 100% to 40 to 50% . Its effectiveness is not equaled by any other device, being an investment that returns every penny in advantages. Removes mold on walls, stains, condensation on windows, and musty odor in the air.

Summary of Products to Remove Moisture from Walls

This is a list of all the available battery of products for humidity in walls:

  1. Anti-humidity Paints:  The use of external anti-humidity paints to waterproof the walls is a very good resource to seal microcracks in the exterior walls that have waterproofing problems. The most common are waterproofing latex (plastered walls) and transparent silicone paints (bricks and exposed concrete).
  2. Resin Injection Blockers:  It consists of the application of a waterproofing liquid based on silicones or silicates in the lower part of the damp walls, in such a way as to create an impermeable barrier. The product reacts with the mineral components of the wall and “crystallizes” generating the moisture block. The liquid is poured into the holes and allowed to penetrate and fill all the capillaries in the walls with moisture. The process is repeated as many times as necessary until total saturation is achieved, normally after 2 to 3 days, until the moisture in the walls disappears.
  3. Wireless Electroosmosis System: It consists of the installation of a small electronic device (15x10x45cm), connected to a household outlet and a javelin. The system thus installed is responsible for emitting waves of modulated frequency, which manage to change the polarity between the walls of the house and the ground. In this way, it is possible to reverse the direction of the rise of the water , reversing the problem of humidity in the walls by capillarity.
  4. Portable dehumidifiers: As we have explained, a dehumidifier is a portable device, similar to an air conditioning unit, that reduces indoor ambient humidity, as well as the typical humidity of the wall.To do this, it filters the air in the room and deposits the water resulting from this condensation in a built-in tank. Filtered air, already with less humidity, returns to the premises helping to reduce ambient humidity. More comfortable air, healthier environments.
  5. Hygroconvectors: Consists of making holes in the lower part of the wall (every 15cm), with a diameter of 18 mm, up to a depth of two thirds of the thickness of the wall. To improve performance, the hole is made on an incline, from bottom to top (approximately 25-30 degrees). Anti-humidity plastic cartridges are inserted in the perforations, in which a heat exchange is generated between the wall and the ambient air. Inside the fig convectors a natural air circulation is created that manages to remove moisture from affected walls.
  6. Mechanical ventilation by insufflation (VMI): It is an integral system that filters the air from the outside, evacuating the internal polluting gases. It also evenly distributes the temperature in the rooms. Suitable for humidity caused by condensation, its installation requires specialized professionals.

Conclusions on Treatments to Remove Moisture from Walls

The anti-humidity systems explained act on walls with existing humidity . Different is the case of new constructions. It is advisable to take the necessary precautions to build correctly so that the humidity of the walls does not become a problem.

To know how to remove moisture from the walls effectively, you will have to implement 2 fundamental actions:

  1. Have a technical diagnosis (think about consulting) to identify the origin of the humidity.
  2. With a correct diagnosis, make the right decisions to solve the humidity of the walls, WITHOUT MASKING IT