Floor Heating Installation in Prefabricated Slab Houses

Prefabricated slab houses can have floor heating installed, but safety must be the top priority. Dry-type floor heating is preferred, while wet-type floor heating requires strict evaluation and professional installation; otherwise, radiators or air conditioners are recommended. Here is a detailed analysis:

I. Dry-type Floor Heating: A More Reliable Choice The load-bearing capacity of old-style prefabricated slabs is usually up to 200 kg per square meter. The cement backfill layer of wet-type floor heating weighs as much as 150 kg per square meter. When combined with the weight of tiles and furniture, it can easily exceed the limit, posing safety risks. In contrast, dry-type floor heating directly lays pipes using aluminum film plate clips beneath the floor. The entire system weighs only about 30 kg, which is just one-third of that of wet-type floor heating. Moreover, it heats up quickly and saves floor height (with a thickness of less than 5 cm), making it suitable for old house renovations. For example, after installing dry-type floor heating in an old house in Nanjing, the floor height remained at 2.75 meters, balancing practicality and space utilization.

II. Wet-type Floor Heating: Requires Strict Conditions If you insist on installing wet-type floor heating, the following conditions must be met:

1. Professional Load-bearing Evaluation: A structural engineer must calculate the floor's load-bearing capacity to ensure that the total weight (including floor heating, backfill layer, furniture, etc.) does not exceed 200 kg per square meter, preventing floor cracking or collapse due to overloading.
2. Lightweight Backfill Material: Use lightweight expanded shale concrete with a backfill layer thickness of no more than 5 cm to reduce the overall weight.
3. Avoid Drilling Damage: Prefabricated slabs are highly vulnerable to random drilling. Use static cutting techniques and ensure that cracks do not exceed the thickness of a hair during acceptance inspection to prevent structural instability caused by improper construction.

III. Alternative Solutions: Radiators or Air Conditioners If the load-bearing capacity or floor height does not meet the standards (standard floor height is 2.8 meters), consider installing exposed radiators (weighing about 20 kg) or using air conditioners for heating. Radiators are easy to install and highly safe, while air conditioners do not require additional structural modifications, both avoiding the pressure on load-bearing capacity caused by floor heating.

IV. Policy Reminder Some northern regions offer subsidies for old house renovations, up to 800 yuan per square meter. Applications must be made through official channels to further reduce renovation costs.

Summary: Safety should be the core consideration when installing floor heating in prefabricated slab houses. Dry-type floor heating is the preferred choice due to its lightweight nature and convenient installation. Wet-type floor heating requires strict load-bearing evaluation and standardized construction. If conditions are limited, radiators or air conditioners are safer alternatives.