Sealing Solution for Modular Timber Construction – Trelleborg ST Seal combines two materials into a single high-performance product for sealing thresholds and wall joints in timber structures: ST Seal. The seal consists of a polyethylene (PE) film with two EPDM tubes—materials commonly used on construction sites for assembling prefabricated wall elements—providing reliable protection against moisture and other environmental influences at the joints.
The production of wall and ceiling elements is no longer just a topic within the prefabricated housing sector. With the growing demand for affordable housing, modular construction is increasingly attracting attention in the construction of multi-story residential buildings. In this context, the production of timber wall elements offers many advantages but also presents challenges. In particular, thresholds and wall joints can become weak points if they are not properly sealed.
Sealing Solution for Modular Timber Construction – Against Moisture and Surface Irregularities
For this reason, Trelleborg has developed ST Seal—a product specifically designed for forming thresholds and wall joints. When used directly on-site during the assembly of wall elements, ST Seal reliably protects the structure against moisture, wind, cold, heat, and noise.
The seal consists of a vapor-impermeable PE film approximately 200 μm thick, with two tubes made of EPDM cellular rubber. The tubes are closed-cell, coated, and have a diameter of 10 or 20 millimeters. Inside the seal, a wide, airtight chamber is formed, providing a stable and insulating layer of air.
Thanks to the materials used, the seal is durable and highly resistant to aging. Its primary application is sealing foundation points. The seal is placed between the foundation and the wall element, with the PE film on top and the tubes at the bottom. In this way, the seal effectively protects against moisture ingress and compensates for surface irregularities.
Another application of the sealing solution for modular timber construction is wall joints. In this case, the profile seals the vertical space between two consecutive wall elements. The PE film is available in widths ranging from 60 to 500 millimeters and can be used for both exterior and interior wall elements of various thicknesses. Overlapping plastic floor coverings and connections with moisture barriers are also possible without issues. The product has been approved by MPA Braunschweig, a building materials testing institute.
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