In the construction of building ventilation systems, the treatment of joints in silicate board assemblies directly affects the system's air tightness and fire resistance performance. According to the requirements of GB50243, "Code for Acceptance of Construction Quality of Ventilation and Air Conditioning Engineering," the joints between boards must form a continuous, sealed fire barrier. During actual construction, special attention should be paid to the preparation of the joint substrates: use dedicated cleaning tools to remove any loose dust from the edges of the boards, ensuring that the bonding surfaces are dry and smooth.

　　The selection of sealing materials should take into account the operating environment of the system. High-temperature-resistant silicone sealants are suitable for conventional environments, whereas fire-rated sealants containing ceramic fibers are more appropriate for high-temperature smoke exhaust systems. During installation, a double-sided application method should be employed: first, apply a 1.5-mm-thick layer of sealant evenly onto the joint surfaces of the panels; after joining the panels, cover the seam surface with a sealing layer at least 20 mm wide. For irregularly shaped joints, it is recommended to use prefabricated arc-shaped transition pieces in combination with elastic sealing strips for enhanced reinforcement.

　　Environmental factors significantly affect sealing performance. When the construction environment temperature falls below 5°C or the relative humidity exceeds 85%, low-temperature sealing materials should be selected, and the curing time should be extended. After completing the sealing treatment, an airtightness test must be conducted. When using the smoke test method, no visible smoke leakage should be observed at the joints. During routine maintenance, infrared thermal imaging cameras can be used periodically to monitor the temperature distribution at the joints, enabling timely detection of potential sealing failures.

　　Engineering practice has shown that adhering strictly to the joint treatment standards specified in JGJ141, "Technical Code for Ventilation Ducts," can ensure that silicate board ventilation systems achieve their designed service life. For special environments such as medical facilities and laboratories, it is also necessary to consider the mold-resistant and antibacterial properties of sealing materials; if needed, a protective coating can be applied to the surface of the sealing layer.