Concrete Slab

To protect the foundation from atmospheric moisture, a waterproof slab around the house must be installed, preventing water from seeping under the walls. The most popular material for this purpose is concrete. It offers the best balance of cost and quality, and almost every homeowner can install it independently.

However, incorrect installation may cause more harm than good—after winter, the slab cracks and loses its waterproofing ability. Therefore, strict adherence to the technology is essential—it will prevent unnecessary expenses, time, and effort in the future.

Stages of Concrete Slab Installation

When installing a concrete slab, it is essential to follow a specific sequence of actions and carefully select materials. Begin by defining the proper workflow for creating a high-quality concrete slab:

• excavate a trench along the foundation's foundation wall, with a width not less than that of the foundation itself;
• build formwork from wooden boards along the trench, which will hold the poured concrete mixture;
• fill the trench with a layer of sand up to 20 cm thick, serving as the base for the slab;
• lay a layer of gravel approximately the same thickness on top of the sand, then compact the entire base thoroughly;
• place a special metal mesh on top to reinforce the poured concrete—ensure all joints are securely tied with wire;
• after this, pour the concrete mix into the formwork, maintaining a slope of about 7 degrees from the building walls; the slab thickness at the wall base must be at least 15 cm;
• to prevent cracking, cover the slab with a light- and water-impermeable film for several days.

How to Prepare High-Quality Concrete

Since concrete is the main structural component of the slab, a detailed explanation of its independent preparation is necessary. The mix includes Portland cement M500, clean river sand with a fineness modulus of 2.6, and crushed stone with a fraction up to 20 mm.

Clearly, cement is the primary component in concrete, and its correct selection determines the durability of the finished slab. The main risk during purchase is acquiring low-quality material. Unqualified workers often mix good cement with granite dust, dolomite, or similar fillers, which negatively affects the material’s performance.

To avoid such issues, purchase cement only from reputable manufacturers and their authorized representatives. It is best to buy in 50 kg bags—branded packaging may consist of one layer of polyethylene or multiple layers of specially treated paper.

When purchasing, note that cement retains its full properties for no more than 3 months after production, so always check the manufacturing date on the packaging. Packaging with second-by-second marking is especially valuable—this feature is absent in counterfeits, as genuine cement will never have identical packaging times, while fake products will.

For high-quality concrete, mix 1 part M500 cement, 2 parts river sand, and 4 parts crushed stone. Use as little water as possible—mix sand and cement dry. In an ideal case, 0.6 parts water are needed for proper concrete.