Doing Basement Waterproofing with Your Own Hands

When building a house or a summer house, many people choose a building with a basement or ground floor in order to use the square meters productively: to arrange a cellar, storage room, boiler room and other utility room there. If you doubt the need for basement waterproofing, in this article we will consider why it is needed and how to do it yourself.

Why is it important to waterproof your basement?

Let’s figure out what kind of moisture has a negative impact on basement structures and what consequences this can lead to.

Precipitation

The foundation and basement are protected from moisture outside the building by a blind area. But it does not guarantee complete protection against leaks during heavy rainfall or heavy snowmelt. To be sure of the safety of your home’s structures, you need to waterproof the basement walls and foundation from the outside. Its absence will lead to premature corrosion of concrete and reinforcement.

Groundwater

Water saturates the soil around the house with moisture, which is absorbed into the concrete foundations, destroys it and penetrates into the interior, forming mold on the basement walls.

What materials should be used for basement waterproofing with your own hands?

There are various materials on the market for protecting the basement from moisture, but the most effective are fused bitumen roll materials and mastic waterproofing. Below we will talk in more detail about mastic protection.

Mastic waterproofing

It is important to note that protection of the basement from groundwater from the outside can be done with mastic only if certain conditions are met: classic bitumen materials can withstand up to 3 m of water pressure, bitumen-polymer materials – up to 10 m.

Important: The main waterproofing of the basement is done from the outside by vertical waterproofing of the foundation. During new construction and the construction of the basement, waterproofing is first installed on the concrete base, then the horizontal and vertical parts of the foundation are installed, and only then the vertical waterproofing is installed. This creates a closed loop. If you do not protect the foundation from water, this will lead to the destruction of the concrete and the appearance of water in the basement.

Mastic inside the basement is used exclusively for horizontal waterproofing on the basement floor under the screed. A primer is also required to prepare the surface. Since the basement is a poorly ventilated room, it is recommended to use water-based materials that do not contain solvents. They are odorless, do not harm the environment or human health, and dry quickly.

Water-based mastic basement waterproofing has a number of advantages:

• seamless waterproofing;
• high drying speed: at +20 °C and normal humidity, the drying time of the primer is no more than 60 minutes, one layer of mastic – 6-12 hours;
• application of mastic on vertical surfaces up to 3 mm at a time: it is permissible to perform waterproofing in one layer, which saves time;
• Possibility of application on damp surfaces (up to 10% allowed).

But the main advantage of mastic waterproofing is that it can be easily done by yourself without the involvement of specialists. For this, the only tools required are a roller and a spatula.

How to Waterproof a Basement Yourself – Step-by-Step Instructions

Let’s look at step-by-step instructions for waterproofing a basement floor with AquaMast primer and water-based mastic :

• After the first layer of floor screed is poured, let it dry and gain strength. Clean the floor surface from dust and dirt using a brush or vacuum cleaner. If cracks have formed before waterproofing the basement, seal them with cement composition.
• Make sure that the temperature of the primer and mastic before application is not lower than +20 °C, and the temperature of the base is not lower than +5 °C. Prepare the primer for application – mix it.
• Apply the primer with a fur roller along the entire perimeter of the screed. In the corners and where the screed adjoins the walls, treat the surface with a brush.
• The drying time of the primer is no more than 60 minutes. It may vary depending on the humidity level and the average temperature of the room. The surface can be considered dry if there are no traces of bitumen left on the napkin applied to it.
• Apply the first layer of mastic with a brush, spatula, or by pouring and leveling. The thickness of each applied layer should not exceed 1.5-2 mm for conventional solvent-based mastics, and 2-3 mm for water-based ones.
• In places where horizontal surfaces adjoin vertical surfaces (walls, pipelines) and other protruding structures, waterproofing is provided to be continuous to a height of at least 200 mm from the floor covering level and requires the installation of transition sides (fillets), which can be made from a cement-sand mixture or C-XPS fillets, and it is also necessary to additionally reinforce the transition with reinforcing material (fiberglass mesh) with an overlap of at least 100 mm on the horizontal and vertical surfaces.
• When waterproofing a basement yourself, be sure to let the first layer of mastic dry before applying the second. The mastic can be considered dry if there are no traces of bitumen left on the napkin applied to it.
• Apply the second layer of mastic in the same way. The total thickness of the waterproofing after the mastic has dried should be at least 2 mm.
• We recommend that without waiting for it to dry, cover the second layer of mastic with sand to increase the adhesion between the screed and the mastic; after drying, sweep away the excess sand.
• The base is ready for pouring the screed.

The impact of precipitation, groundwater and condensation can negatively affect the condition of the basement building structures. To prevent dampness and destruction, well-thought-out protection is necessary. Reliable waterproofing of the basement can be easily done independently using AquaMast water-based mastics and primers.

The water resistance of the treated surfaces is achieved after 8 hours at +20°C and ensures a long service life of the foundation and basement structures of your home.

Read Other: New Foundation Under Existing House: Residential Foundation Contractors