Autonomous heating: the secret of a perfect screed for a warm floor without cracks

With the onset of autumn and the first cold weather, the issue of energy independence becomes critically important for every homeowner. Right now is the perfect time to think about efficient autonomous heating, where underfloor heating is one of the best and most comfortable options. It provides uniform heating of the room, creates comfort and allows you to significantly save on energy resources.
However, the heart of this system is not just pipes or cables, but a cement-sand screed that directly transfers heat. It operates in extreme conditions: regular cycles of «heating-cooling» cause the concrete to expand and contract. Without proper internal protection, such a structure is doomed to cracks and premature failure.

Based on our many years of practical experience in the construction and arrangement of floors, we have tested dozens of reinforcement technologies. Our conclusion is unequivocal: the best solution for the durability of a heated floor is the use of polypropylene fiber. Moreover, to guarantee the impeccable quality of every square meter, we refused to compromise with questionable materials and independently export to Ukraine the highest quality professional fiber — Astra ProMicro 12 mm.
Let’s find out why these microscopic fibers are critically important for your home and why we chose this particular brand.

Physics of the process: why does ordinary screed crack?
Concrete and cement mortars have excellent compressive strength, but low tensile and flexural strength. When the underfloor heating is turned on, the coolant heats the lower layer of the screed. It expands faster than the upper layer, which creates strong internal stress.
If the solution does not have internal elasticity, microcracks form. With each new heating switch-on, they grow, which leads to two problems:

— Air voids: Air pockets form around pipes. Air is a poor conductor, so heating efficiency drops dramatically and heating costs increase.
— Destruction of the finish: Cracks from the screed «reflect» on the tile (it cracks or moves away from the base) or deform the laminate and parquet.

Why did we choose Astra ProMicro 12 mm?
Over the years, we have seen how cheap or low-quality fiber behaves: it clumps, does not distribute in the solution, or has fibers that are too thick and do not provide the necessary adhesion.
Astra ProMicro 12 mm is a new generation professional fiber that we selected according to strict criteria:

— Ideal length of 12 mm: This is the standard size for cement-sand and semi-dry screeds for underfloor heating. Fibers of this length create the most dense and durable reinforcing mesh inside the solution.
— Ultra-fine fibers and oil coating: Astra ProMicro fibers are coated with a special composition that promotes their instant and uniform distribution in the solution without the formation of «hedgehogs» or lumps.
— Three-dimensional «skeleton» (3D reinforcement): Unlike a metal mesh that lies in only one plane, millions of Astra ProMicro fibers bind the solution in all directions, working as microscopic shock absorbers.

The main advantages of the Astra ProMicro 12 mm fiber screed:

1. 99% Crack Blocking: Most cracks appear in the first 24 hours due to shrinkage during drying. The fiber retains moisture and prevents the cement stone from cracking.
2. Thermal shock absorption: Polypropylene fibers absorb internal stress during heating of concrete, maintaining structural integrity.
3. Maximum thermal conductivity: Thanks to the fiber compaction of the solution, the number of air pores in the screed is minimized. This allows the floor to warm up faster and more evenly, saving you money on energy.
4. Impact and wear resistance: The screed becomes monolithic and impact-resistant, which protects it from accidental damage during subsequent repairs.

Proven technology from our experts
As a direct importer and practitioner, our company strictly controls the correct application of the material. To get the perfect result, we recommend:

Proportions: The optimal dosage is 0.9–1.2 kg of Astra ProMicro fiber per 1 cubic meter of solution.
Mandatory tandem: Fiber acts as reinforcement, but to remove air and make the mixture plastic, we always use it together with the professional plasticizer Protex TP-6 of our own production.
High-quality mixing: Thanks to the unique structure of Astra ProMicro, it is perfectly mixed into both classic wet mortar (in a concrete mixer) and modern semi-dry screed (using a pneumatic supercharger).

Polypropylene fiber is an affordable but critically important component of a heated floor. Saving on this material can cost you the dismantling of expensive tiles or the reworking of the entire heating system. By choosing our experience and the original Astra ProMicro 12 mm fiber, which we supply directly, you are investing in reliability that will protect your floor for decades.
So that we can prepare an individual offer for your facility, please contact our specialists.