Glazing Systems

Fig. 33

In general, the total rabbet depth for each profile should include a minimum of 3/4 inch sheet engagement and an allowance for thermal expansion. Due to the rib geometry of 16 mm and thicker Multiwall sheet, additional precautions should be taken. In this case it is important that the sheet is cut so that as least one rib is located in the center of the rabbet, as shown in Figure 33.

Dry Glazing Systems
This selection illustrates some glazing proposals, illustrating profiles which have been successfully used in combination with multiwall sheet. Situations may occur where sheet expansion ( sheet dimension greater than 4'x 4')exceeds sealant limitations and often for aesthetic reasons, this type of "dry" glazing system is an ideal solution.

The advantage and necessity for dry systems is that the rubber gaskets are 'snapped' into the glazing strips which then allow free movement of the sheet during expansion and contraction. See fig. 34 and 35.

Warning
Do not use PVC gaskets!

Due to migration of additives (Plasticizers) from soft  PVC  Polycarbonate  can be chemically affected resulting in surface cracks or even sheet breakage.

MJK Multiwall Systems, LLC offers range of easy to use glazing bars and fixing accessories, designed specifically for glazing Multiwall & monolithic polycarbonate and acrylic sheet.

Fig. 34

Fig. 35

Wet Glazing Systems
This type of installation system is mainly used in small (leas than (4x4) domestic applications: car ports, warehouses, conservatories and other glass replacement situations.

With standard metal profiles or wooden sections, in combination with glazing tapes and glazing compounds, many different configurations are possible. See fig. 36 and 37.

When using glazing compounds it is essential that the sealant system accepts a certain amount of movement, to allow for thermal expansion, without loss of adhesion to the frame or sheet. Silicone sealants (100% solids) are generally recommended for use with Polycarbonate sheet, but it is strongly advised when using sealing compounds to check compatibility before use.

Care should be taken not to use amino or benzamide curing silicone sealants, which are not compatible with Polycarbonate sheet and result in micro-cracks particularly when stress is involved. See fig. 22 for sealant recommendations.

Fig. 36

Fig. 37

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