What are the advantages of thick-layer self-leveling cement in underfloor heating backfilling?
Release Time:
2016-06-29
Source:
What are the advantages of thick-layer self-leveling cement in underfloor heating backfilling?
Revolutionize conventional underfloor heating installation by using self-leveling screed for a single, seamless fill, resulting in a smooth, even surface that is ready for direct flooring installation.
Use of lightweight materials: the filling layer has been changed from the original 50-mm-thick pea-gravel concrete to a 15- to 30-mm-thick self-leveling cement mortar layer. This self-leveling cement mortar layer can simultaneously address two major challenges in construction—cracking of the floor surface and insufficient floor flatness. Such a change can significantly reduce the structural load, allowing for smaller cross-sections of beams, columns, and foundations; moreover, with the storey height remaining unchanged, it increases the usable headroom within the building, or, alternatively, enables a reduction in storey height while maintaining the same interior clear height. Consequently, substantial savings in construction materials and lower overall construction costs can be achieved. On the other hand, when these older buildings are demolished, the volume of construction waste is also reduced. There is no doubt that these characteristics will have a positive impact on the construction, operation, and demolition phases of buildings, delivering significant economic, social, and environmental benefits.
System Features
Lightweight and thin — meeting the needs of architectural design
A self-leveling cement mortar with a thickness of 15–30 mm is used, whereas the conventional method employs 50-mm-thick pea-gravel concrete. This change significantly reduces the structural load, allowing for smaller cross-sections of beams, columns, and foundations, thereby substantially decreasing the stress on the foundation. Moreover, it increases the usable floor-to-ceiling height without altering the story height, or enables a reduction in story height while maintaining the same interior clear height—making it particularly well suited for retrofitting heating systems in existing buildings.
Addressing the issue of cracking in the floor after the screed layer has been applied
Ground cracking is primarily determined by the temperature difference across the floor and the absolute floor temperature. In conventional underfloor heating systems, the supply water is typically set at 60°C and the return water at 50°C, resulting in a large temperature differential and significant thermal expansion and contraction of the floor surface, which can easily lead to cracking and deformation. By contrast, when high-efficiency terminal units are added to the radiant surface, the supply water temperature can be substantially reduced, thereby narrowing the temperature differential. Under these conditions, the floor temperature closely resembles the heating pattern experienced during summer, when no cracking occurs and the flooring does not undergo thermal expansion or contraction. Consequently, high-efficiency underfloor heating terminals allow for a significant reduction in the thickness of the screed layer while still achieving rapid heat-up, effective heat storage, and energy savings. (Note: The combined application of ultra-smooth, fast-setting self-leveling cement in underfloor heating systems is still in the exploratory stage and requires at least one complete heating season of trial operation to evaluate the results. While ensuring the performance of the screed layer in the underfloor heating system, the minimum allowable thickness of the self-leveling cement depends on the specific installation method employed. Given the inherent characteristics of high-efficiency terminal units—namely, moderate floor temperatures, strong compressive strength, and rapid heat-up—it is possible, while maintaining system performance, to test the lowest feasible thickness of the self-leveling screed, thus achieving both optimal functional performance and economic benefits.)
One-step molding to resolve flatness issues.
Advantages of Natural House Self-Leveling Compound for Underfloor Heating Backfill Applications
1. The product is flowable and can be placed using manual or mechanical pumping.
2. With a construction thickness of 30 mm or more and no cracking, this is an exceptionally high-quality underfloor heating backfill mortar.
3. The compressive strength of the material shall be not less than C20.
4. The flatness shall meet the requirement of a deviation of no more than 2 mm when measured with a 3-meter straightedge.
5. No traditional curing is required; other interior finishing work can be carried out 24 hours after construction.
(After 2 hours of summer construction or 6 hours of winter construction, the Shore hardness reaches 60, allowing personnel to walk on the surface.)
6. After construction, there is no need to install the floor finish or the leveling layer; other flooring materials can be directly laid on the surface, thereby shortening the construction period and reducing labor costs.
