Floor Heating for Prefabricated Slab Houses

When installing floor heating in prefabricated slab houses, it is advisable to prioritize dry-type floor heating or conduct a rigorous assessment before construction to avoid safety hazards caused by overloading. Here are the specific plans and precautions:

I. Safety Solutions

1. Prioritize Dry-Type Floor Heating
   Dry-type floor heating uses aluminum film panels to hold pipes and directly lay flooring. The system weighs only about 30 kg per square meter, which is just 1/5 of that of wet-type floor heating (including cement backfill). It heats up quickly (about 30 minutes), making it suitable for temporary use scenarios. The system thickness is only 12 - 30mm, eliminating the need for a concrete backfill layer. It dissipates heat rapidly through the aluminum foil layer, with heat loss as low as 12%. It can directly accommodate wooden flooring or be laid with anti-rust aluminum panel modules followed by tiles/marble. For example, the renovation of the old teaching building at Chongqing Yicai School has demonstrated its stable performance, proving its feasibility.

2. Professional Assessment for Wet-Type Floor Heating
   If you insist on installing wet-type floor heating, a professional team should assess the floor slab's load-bearing capacity. Lightweight pea gravel concrete should be used for backfill, with a thickness not exceeding 5 centimeters. However, it should be noted that prefabricated slab houses built before 1998 generally have lower steel reinforcement configurations and are not recommended for traditional wet-type floor heating installation unless a structural engineer assesses and confirms that the load-bearing capacity meets the standards.

3. Alternative Heating Solutions
   If the load-bearing capacity is insufficient, radiators (weighing about 20 kg per unit) or air conditioning can be used for heating. Radiators should be fixed to load-bearing walls to avoid damaging the steel reinforcement structure by drilling holes on your own (there have been cases where homeowners caused balcony cracks by drilling holes). Air conditioning heating does not require floor modification but requires attention to energy consumption.

II. Construction Points

1. Dry-Type Floor Heating Construction Process
   The modular design allows for same-day installation completion. The steps include planning pipe layout (avoiding pipe intersections), laying modules (ensuring the aluminum film layer faces upwards), and pipe embedding and pressure testing (the pressure should be maintained above 0.6MPa for 24 hours without leakage). After construction, a moisture-proof film should be covered before laying the flooring or tiles.

2. Temperature Control
   For the first use, the temperature should be increased gradually (2 - 5℃ per hour) to prevent wooden flooring from deforming due to thermal expansion and contraction. For long-term use, it is recommended to set the water temperature not exceeding 55℃ to avoid aging of the aluminum film layer.

3. Policy Subsidies
   Some northern regions offer subsidies for old house renovations, up to 800 yuan per square meter. It is necessary to consult the local housing and construction department in advance and submit a load-bearing assessment report.

III. Risk Warnings

Construction without assessment may cause cracks in the ceiling below. It is essential to strictly adhere to the static cutting process (such as using a water drill for floor removal). During acceptance, check for ceiling cracks. If the cracks exceed the thickness of a hair (about 0.05mm), it is considered unqualified, and the floor slab needs to be reinforced or the construction redone.