Cement Prefabricated Panels for House Topping Out

Cement prefabricated panels can be used for house topping out, but they should be selected with caution based on specific scenarios and requirements.

Cement prefabricated panels are cement components prefabricated in factories. During production, a wooden model is first nailed together, then steel bars are arranged and cement is poured in, ultimately forming two types: solid or hollow. In the construction of topping out for new houses, the application process involves using a large crane to lift the prefabricated panels steadily and transport them to the roof position. Then, bricklayers work together to precisely align the gaps between the panels and arrange them one by one until the entire roof is covered. This construction method still has certain application value in specific scenarios, such as projects with tight schedules or cost-sensitive projects, where the standardized production of prefabricated panels can shorten on-site construction time.

However, cement prefabricated panels have significant drawbacks that require special attention:

1. Poor waterproof performance: In rural self-built houses, the probability of rain leakage is relatively high when using prefabricated panels for the roof, with 8 out of 10 houses potentially experiencing leakage problems. This is mainly due to the difficulty in treating the gaps at the joints of the panels. If the construction process or material quality does not meet the standards, it is very easy to form water seepage channels.
2. Insufficient thermal insulation: Prefabricated panels are of a single cement structure with high thermal conductivity efficiency, resulting in significantly higher indoor temperatures in summer and lower temperatures in winter compared to the outdoors. Usually, it is necessary to cover an insulation layer or secondary roofing materials (such as tiles or insulation boards) on the floor slab to improve thermal performance.
3. Low seismic performance: The connection between the prefabricated panels and the main structure relies on local nodes, and the overall integrity is relatively weak. Under earthquake action, they are prone to detachment or fracture. Therefore, the use of prefabricated panels as load-bearing structures is explicitly prohibited in earthquake-prone areas (such as seismic fortification intensity zones of 8 degrees and above).

With the development of building technology, cast-in-place concrete (with good overall integrity and strong seismic resistance) and prefabricated buildings (with a high degree of standardization and excellent construction efficiency) are gradually replacing traditional prefabricated panel houses. Since 2022, China has implemented a policy of old community renovation, focusing on repairing and renovating prefabricated panel houses and only demolishing buildings that meet the standards for dangerous houses. If cement prefabricated panels need to be used, it is recommended to give priority to hollow panels to reduce their self-weight and strictly control the construction quality, with a particular focus on strengthening waterproof treatment and node connections.