Prefabricated Components for Roof Covering

Prefabricated components for roof covering usually refer to roof prefabricated panels, which are a form of roof construction using prefabricated panels as the main components.

Types and Production

Roof prefabricated panels are cement components prefabricated in factories. During production, a wooden mold is first nailed together, and then steel bars are arranged and cement is poured to form the panel. They come in two types: solid and hollow. The hollow structure achieves lightweighting by reducing the non-load-bearing concrete, maintaining a certain strength while reducing its own weight.

Application History

This form of construction originated in the early 20th century and was initially mainly used for floor slabs and roof insulation layers. In China, most residential buildings constructed before 1985 adopted this type of structure, playing an important role in the construction field at that time.

Advantages and Disadvantages

• Advantages: The price is relatively low, and the construction speed is fast. In rural self-built houses, using prefabricated cement panel roofs can complete hoisting in one day or half a day, greatly shortening the construction period and saving labor and time costs.
• Disadvantages:
  • Waterproofing issues: There is a relatively high probability of water leakage during waterproofing. In rural areas where prefabricated panels are used as roofs, 8 out of 10 households experience water leakage, which brings many inconveniences to residents' lives.
  • Poor earthquake resistance: They cannot be used in earthquake-prone areas because their earthquake resistance coefficient is too low, and they are prone to collapse under earthquake action, threatening people's lives and property safety.
  • Poor thermal insulation: The thickness of the floor slab is generally about 12 centimeters. Although it is hollow, its thermal insulation is poor. The indoor temperature is high in summer and low in winter. Generally, secondary roofing materials need to be covered on the floor slab to make up for this defect.

Market Situation

There are various brands of roof prefabricated panels, such as Shenbo, Yongshi, and Hengxinrui. The core materials include composite materials, concrete, inorganic materials, and rock wool. The compressive strength has various specifications such as 0.24 MPa and 1.0115 MPa, and the flexural strength has different parameters such as 0.3 MPa and 9.6127 MPa. There are also various concrete prefabricated house-related products on the market, such as reinforced concrete prefabricated houses and modular integrated houses, with prices varying according to product types and manufacturers.

Development Trends

With the development of construction technology, cast-in-place concrete and prefabricated buildings are gradually replacing traditional prefabricated panel houses. Prefabricated buildings use modular factory-prefabricated components. For example, CMC combined modular buildings improve earthquake resistance through steel-concrete integral pouring, and the construction period is 30% shorter than traditional methods. Since 2022, China has implemented a policy of old community renovations, mainly focusing on the repair and renovation of prefabricated panel houses, and only demolishing buildings that meet the standards for dangerous houses.