Screeding Preparation and Installation
Proper preparation is crucial for achieving a high-quality, durable screed surface. At Premier Screeding, we understand that meticulous preparation ensures a long-lasting and hard-wearing floor. Here’s a step-by-step guide to our screeding preparation and installation process.
Preparation
Before pouring any screed, it’s essential to eliminate all contaminants such as grease, paint, loose debris, or oil from the base. These substances can adversely affect the bonding capability of the screed. If cleaning products are used, it’s vital to ensure no residues of soaps or detergents remain, and the surface should be allowed to dry naturally. Any cracks or crevices must be fixed to prevent them from appearing on the new screed surface. Our team addresses these issues during the on-site survey to ensure the base is thoroughly prepared.
Damp Proof Membrane (DPM)
Before screeding, a DPM must be installed to protect the final flooring and screed from moisture damage. This usually involves laying two or three layers of polythene to act as a barrier between the screed and the insulation layer. In areas at risk of radon gas, an additional barrier may be required to prevent gas infiltration. For significant radon levels, a complete ventilation system might be installed beneath the screed layer to remove any seeping gases.
Applying Sealants and Primers
Once the floor base is prepared and membranes are installed, a sealant or primer is applied. These substances aid in the bonding process and are specifically matched to the type of screed being used. Trained technicians apply these materials in the correct ratios using airless sprays and specialized equipment, ensuring optimal bonding and durability.
Underfloor Heating Installation
If you are installing underfloor heating, this is the stage where it is set out and installed. The heating pipes or wires are securely attached to insulation panels to prevent movement and ensure correct positioning. Underfloor heating provides efficient, even warmth across the floor, making it an excellent choice for modern homes.
Pouring the Screed
If underfloor heating is not being installed, you can proceed directly to pouring the screed. The specific requirements of the room will dictate the type of screed used. Even quick-drying and advanced screeds require at least 24 hours before the surface can be walked on and a minimum of 72 hours before any flooring materials are applied. Following manufacturer’s drying guidelines for standard and heavy-duty screeds is essential to achieve a quality finish and a stable, even floor surface.
Quality Control and Testing
After the screed has set enough to walk on, the SR (Surface Regularity) level of the screed is evaluated. This involves using a 2m long straight-edge to check for deviations:
• SR1: Deviations of 3mm or less, indicating the highest quality screed.
• SR2: Deviations of 5mm or less, suitable for commercial and industrial floors.
• SR3: Deviations of 10mm or less, for floors where finish is less critical.
In some cases, a structural engineer may perform a soundness test to verify the screed’s strength and suitability for load-bearing environments. This might include a “drop hammer test” to assess the flexibility and strength of the screed. Only experienced structural engineers following British Standards BS8204 regulations are qualified to conduct these tests and certify the structural safety of the screeding.
By following these meticulous preparation and installation steps, Premier Screeding ensures that your floor is durable, high-quality, and built to last. Contact us today to learn more about our comprehensive screeding services.