Tile Flooring for Prefabricated Slab Houses

Prefabricated slab houses can have tile flooring, but specific conditions must be met and operational standards strictly followed, especially for old houses that have been in use for over 30 years, where risk assessment is crucial.

1. Load-Bearing Inspection is Essential

The floor slabs of prefabricated slab houses are assembled from prefabricated components. Over time, due to material aging and accumulated loads, cracks, deformations, or steel bar corrosion may occur. For prefabricated slabs that have been in use for 30 years, it is essential to inspect for obvious cracks (width exceeding 0.3mm warrants caution), local sagging, or exposed and corroded steel bars. If these issues are present, directly laying tiles may cause further damage to the floor slab or even lead to collapse risks. For old houses, it is recommended to commission a professional agency to test the load-bearing capacity of the prefabricated slabs and assess whether they can withstand the total weight of tiles, cement mortar, and daily usage loads.

2. Reinforcement Measures to Reduce Risks

If the floor slab shows signs of instability, reinforcement is needed to enhance its load-bearing capacity. Common methods include cross-beam reinforcement and steel beam support:

• Cross-beam reinforcement: Pour reinforced concrete cross-beams beneath the prefabricated slabs to disperse loads and enhance overall stability, suitable for areas with insufficient local load-bearing capacity.
• Steel beam support: Install steel beams beneath the floor slab to reduce concentrated forces on individual prefabricated slabs, suitable for slabs with large spans or significant deformations.
  After reinforcement, allow at least 28 days for curing to ensure the concrete or steel structure reaches its design strength before laying tiles.

3. Base Treatment and Laying Methods

• Base treatment: Thoroughly clean the floor slab surface of dust and oil stains, and repair pits or hollow areas with cement mortar. The flatness error should be controlled within 2mm/2m to prevent tile cracking due to an uneven base.
• Laying methods:
  • Wet laying method: Soak the tiles until no bubbles appear, then dry them in the shade. Lay them with cement mortar and allow them to rest for at least 48 hours after laying, suitable for ordinary non-underfloor heating rooms.
  • Dry laying method: First, lay a layer of dry hard cement mortar (thickness approximately 3-5cm), then lay the tiles, suitable for underfloor heating rooms to reduce the impact of thermal expansion and contraction on the tiles.

4. Joint Treatment and Professional Assessment

• Joint treatment: Fill the joints between prefabricated slabs with flexible sealant or glass glue, and leave 1-2mm expansion joints between tiles to prevent tile hollowing or cracking due to slight deformations in the floor slab.
• Professional assessment: Before laying tiles in old houses, a structural engineer must issue a written assessment report clarifying the floor slab's load-bearing capacity and reinforcement plan. If overall deformation or severe steel bar corrosion is detected during testing, structural repair or renovation should be prioritized over directly laying tiles.

Summary: Tile flooring in prefabricated slab houses should prioritize structural safety, ensuring protection through load-bearing inspection, reinforcement treatment, standardized construction, and professional assessment, especially for old houses where blind operations should be avoided.