What are the causes of wet walls of the house?
The cause of moisture in the walls is very diverse. In many cases, it can penetrate through the basement, but it can also be caused by undetected water damage caused by a defective pipe. Building physics construction errors even in new buildings, a dilapidated building fabric in existing buildings, or even improper protection in buildings on lakes or flowing water pose a risk.
Moisture can cause major damage to the masonry and accelerate the formation of mold, and heating costs can also skyrocket.
In any case, professional analysis of the cause and damage, as well as the elimination of the problem, is mandatory. An exterior wall of a house usually has to be re-sealed afterward if one of the problems mentioned above could be identified as the cause:
- Soil moisture.
- Slope, seepage, or groundwater.
- Heavy driving rain.
- Defective drainage.
- Capillary rising damp.
Table of Contents: Open me
- Warning Signs, Your Home Has a High Indoor Humidity Level
- Guide to wall tanking & waterproofing
- How to protect wall tanking & waterproofing
- What is the difference between waterproofing slurry and bitumen?
- Waterproofing for your Home – Buying Advice
- Best waterproofing products – Review
- Best waterproofing product for furniture & parquet
- Best Wood Protective Finish
- Best Aerosol Waterproofer
- Best Sealer for Floor
- Areas of application: What is sealing slurry used for?
- Instructions: How is sealing slurry applied?l
- FAQ – Waterproof of the Home
Warning Signs, Your Home Has a High Indoor Humidity Level
- Water Stains
If you observe a stain on your walls or ceiling, you must have it checked to find out which kind of water caused it. Water leaks and broken pipes need to be addressed immediately. Otherwise, it can lead to bigger problems, such as pest infestations and wood rot.
- Condensation on Windows
Your windows may begin to collect moisture if there is too much moisture in your home. The process is called condensation. This indicates that there are high humidity levels in the room, and you should make sure to dehumidify them immediately.
- Spots of Mold
Mold may begin to grow slowly if excessive moisture accumulates for a long time. Allergies, respiratory infections, and asthma attacks are caused by mold. You want to make sure that your family’s health will not be at risk by identifying the issue quickly.
- Smells of Mustiness
Sometimes, you don’t need to notice mold development in your home to know that it is present. You may detect a musty smell in your carpet, ceiling, walls, or even in the ducts of your smell if your carpet, ceiling, walls, or ducts emit any type of musty smell. It is yet another sign that the humidity in your home is too high.
Guide to wall tanking & waterproofing
Waterproofing slurry is an essential material for waterproofing in house construction and renovation. Thus, sealing slurry is the basic protection of structures against water damage and moisture.
Waterproofing slurries are preferably applied in areas that are exposed to increased moisture. Applying waterproofing slurry during construction or afterward can thus prevent visible consequences, such as mold, fungus, wet walls, or standing water. The above-mentioned consequences are mostly due to insufficient waterproofing of the masonry or subfloor and cause high costs afterward.
How to protect wall tanking & waterproofing
A waterproofing slurry is a waterproofing material that is breathable. It prevents the penetration of water into the basement and house but allows vapor to pass. Sealing slurry usually consists of cement, sand, and additives for adhesion and impermeability. The consistency depends on the type of processing required: if the sealing slurry is to be painted, it is mixed correspondingly thinner than when applied with a trowel or spatula. Since the sealing slurry is permanently resistant to frost and weathering due to its constituents, it can be used well outdoors. However, it can also be used in many ways indoors, for example as a sealant in shower areas (walls, floors).
- Variants of sealing slurry
The sealing slurry is divided into two different variants: flexible and rigid sealing slurry. In the flexible variant, plastics are added so that cracks can also be bridged. In the case of the rigid variant, cracks cannot be bridged. On the other hand, it is also suitable for horizontal use, for example on the screed.
What is the difference between waterproofing slurry and bitumen?
Bitumen is a waterproofing compound, just like sealing slurry. Therefore, the question often arises as to what the difference is with sealing slurry. While waterproofing slurry is based on cement, bitumen has its origin in petroleum. To maintain flexibility, plastics and emulsions are added. The main place of application is in all areas in contact with the ground, concrete, and masonry – in other words, outdoors.
In the base area, in particular, bitumen is used as a thick coating for bonding perimeter insulation to the floor slab or to the exterior basement walls. In this way, two steps of a reasonable plinth waterproofing can be done in one. The two types of waterproofing, bitumen and sealing slurry, are not mutually exclusive, however, but rather complement each other. Thus, bitumen can also be applied to sealing slurry, and vice versa. Ultimately, the choice between bitumen and sealing slurry depends on the substrate, the desired properties of the waterproofing, and the subsequent processing.
Waterproofing for your Home – Buying Advice:
Always use a waterproofing product and not damp proof.
Although these two waterproofing products may look very similar, they are very different in how they perform.
Choose the right product from the waterproofing test or comparison.
Waterproofing product
All our reviews are based only on expert judgment or practical experience with most of the waterproofing products we consider. We strive to ensure that our leadership is independent and as detailed as possible.
Best waterproofing products – Review
RadonSeal Plus Deep-Penetrating Concrete Sealer

- Greatly reduces capillary water seepage and water vapor inflow.
- Reduces Cracking.
- ECO-Friendly.
4,9 Rating
Permanently strengthens and hardens outdoor and indoor concrete, walls and floors, to protect against cracking, dusting, efflorescence, freeze-thaw, road salts, deicing chemicals, and minor defects. Protects against the rusting and expansion of rebar which can cause cracking.
BXI Modified Bitumen Waterproof Patch & Seal Tape
After being stuck to a surface, the bitumen will gradually penetrate into the cracks of the surface until they are completely filled. Exceptional Stickiness & Great Stretchy Performance at even low temperatures & High Durability & Anti-corrosion.
MFM Waterproof House Wrap

- A broad temperature range.
- Self-adhering sheet-type membrane.
- Roll Length: 75 ft.
4,9 Rating
Waterproofing membrane with a polymer film with a layer of specially formulated rubberized asphalt adhesive suitable for use on siding and exterior plaster. This house wrap is designed for extreme moisture protection and has mastic selvedge on both edges for improved sealing.
JJ CARE Waterproof Membrane Fabric for Shower Walls, Bathroom Floors, Sauna and Steam Room
Waterproofing membrane are tough because they’re manufactured using only the highest-quality materials. They are durable and tear-proof but still, extremely flexible. Furthermore, we made sure that the sheets you’re getting can easily be folded when used for your wall and floor connections, even for butt joints.
Best waterproofing product for furniture & parquet
Best Wood Protective Finish
Minwax Polycrylic Protective Wood Finish

- Ultra-fast drying, quick recoats after 2 hours.
- Semi-Gloss finish.
- Low odor, non-yellowing.
4,9 Rating
It protects interior wood projects like woodwork, furniture and more, and add natural beauty with Minwax Polycrylic Protective Finish. The crystal clear top coat dries and stays clear, and protects against scratches, scuffs and blemishes to protect the wood surface beneath. It’s ideal for use over all Minwax Oil-Based and Water-Based Stains and colors and all wood species including light woods like maple, ash & birch.
Best Aerosol Waterproofer
Thompsons Clear Multi-Surface Aerosol Waterproofer

- Prevents Water Damage.
- Beads and Waterproofs.
- Effectively seal any porous material against damage by water.
4,9 Rating
This sealer is extremely versatile: aside from waterproofing wood, it can also waterproof concrete as well as seal wood and brick. In other words, it’s got everything you need to protect your outdoor living areas.
Best Sealer for Floor
Green Gobbler Floor Finish & Sealer Wax

- 33% high solid acrylic floor wax & sealer.
- Scuff & Scratch resistant floor finish, for wonderful looking floors.
- Quick and easy application.
4,9 Rating
- Requires half the coats as other floor products
- Scruff and scratch resistant
- Long-lasting shine with patent polymer technology
- Where To Use: All resilient floors, highly visible areas, Hotel Lobbies, Office Buildings, Supermarkets, Schools, Homes & More!
- Great For: Terrazzo, Vinyl Tile, Rubber Tile, Concrete, Asbestos Tile, Linoleum, Stone, Sealed Wood & More!
Areas of application: What is sealing slurry used for?
Sealing slurries are used in both new construction and renovation. Typical applications are:
- Intermediate waterproofing of damp building components
- Perimeter waterproofing: waterproofing of building components in contact with the ground (for example, basements or plinths) and protection against splash water above the perimeter insulation
- Balcony and terrace waterproofing
- Splash water zone in the bathroom (shower area, bathtub area)
Tip: For the waterproofing product you favor, check the manufacturer’s specifications to see if it is suitable for the desired purpose and change the product if necessary. In doing so, note that not every sealing slurry is approved for horizontal use on the floor!
Instructions: How is sealing slurry applied?
The sealing slurry is always applied in at least two layers. A thickness in the millimeter range of 1 to 2 millimeters is produced per layer. Depending on the waterproofing requirements, several or even thicker layers must be applied accordingly. A layer thickness of five millimeters should not be exceeded.
Step 1: Preparation of the substrate
The substrate should be completely cleaned in advance. Old layers of plaster or paint should be removed. A high-pressure cleaner is best suited for spraying off or a wire brush for sweeping the surface.
Sealing slurry should not be applied to substrates with holes or cracks. If unevenness comes to light during cleaning, this must be filled in advance with a suitable repair filler or repair mortar. The basis for the sealing slurry should be a closed surface at the end. Corners or transitions between wall and floor must be filled with a filler and then drawn off to form a cove.
Tip: If the sealing slurry is to be applied to a highly absorbent substrate, it must be moistened beforehand. In outdoor areas, it is sufficient to briefly hose down the respective wall with the garden hose.
Step 2: Mixing the sealing slurry
Material needed:
- Bucket
- Water
- Stirring tool: for example, a drill with a stirring attachment.
The sealing slurry is usually supplied in bags of various container sizes. Select the appropriate container size for your application.
Follow the manufacturer’s instructions for the amount of water and add water and bag contents to the bucket. Stir the two together until a homogeneous, non-clumping mass is formed. When applying with a spatula, the compound should be thicker, while when applying with a trowel, the compound should be thinner.
Tip: The different components may settle to the bottom within the container. Therefore, always mix a container completely and not only half bags.
Step 3: How to apply sealing slurry
To apply sealing slurry, you will need a spatula or trowel and a painting brush – tools that are part of the basic equipment of every do-it-yourselfer.
The ready-mixed sealing slurry is now applied as evenly as possible to the prepared substrate. For inexperienced do-it-yourselfers, application with a trowel is usually easier than with a spatula or trowel. The individual layers must not be applied too thickly. Otherwise, spalling may occur in the medium or long term and the seal will no longer hold.
The individual layers must not be allowed to dry through between applications, otherwise, they will no longer bond with each other but will repel each other. The previously filled transitions between wall and floor or in corners are also coated with the sealing slurry.
Tip: It is better to apply one more coat and then applies the individual coats more thinly.
Step 4: Curing of the sealing slurry
Depending on the brand, the sealing slurry may take several days to dry thoroughly. It should be protected from sun, drafts, rain, and frost with foil. If it is too warm, there is a risk that the slurry will dry through too quickly. It must then be kept moist with the aid of a little water.
When the waterproofing slurry has completely hardened, there is a complete seal against water and moisture.
Tip: If the waterproofing slurry is to be further processed and, for example, plaster applied, the manufacturer’s instructions for subsequent processing must be carefully checked and adhered to. Due to the highly water-repellent properties of the slurry, the plaster may no longer adhere. Some manufacturers therefore specify wet-on-wet processing with a pre-spray mortar.
Reference: What are the main ways to control moisture in your home?
How to Waterproof Walls - Video
FAQ - Waterproof of the Home
❓ How do you know if you have too much humidity?
How can you tell when the humidity is too high inside your home? There are a couple of telltale signs like clammy skin, foggy windows, and a heavy yet warm atmosphere. But you can also smell mildew or musty odors when your home is much too humid, which comes from moisture buildup.
❓ What happens when the humidity levels are too high?
Bacteria and viruses take hold in humid conditions. Spending time in an environment with too much humidity can actually make you sick, especially from respiratory infections. The bacteria and viruses that cause illness to thrive and grow in the air that’s above 60 percent relative humidity.
❓ How do I get rid of moisture in my house naturally?
All you have to do is put some baking soda in a bowl or open container. Then place it in the humid room or area and it will slowly absorb moisture from the air. You can occasionally stir the powder around as it clumps when absorbing moisture. Baking soda isn’t as effective as rock salt or calcium chloride.