Frame fixing

Another possibility for mounting PVC sheets outdoors is using metal U-shaped tracks that are suitable for large signs. Movement of the sheets from expansion or contraction must be taken into account.

Unequal-sided U-shaped tracks have proven to be the most suitable for this mounting PVC sheets. The substructure must be sufficiently ventilated with a lath backing.

Example 3

For a large sign consisting of several KÖMACEL sheets, measuring 3000 x 1000 x 10 mm (118" x 39.4" x 3/8"), mounted in a U-shaped frame, the following expansion joints have to be taken into account:

1. H-section between the sheets
2. Beginning of frame
3. Upper surface of frame

Assume the following temperatures:
Minimum surface temperature: -15°C  (5°F)
Maximum surface temperature: 45 °C  (113°F)
Temperature differential: 60°C   (140°F)
Installation temperature: 20°C   (68°F)

Solution

Change in length (l) for a sheet with a total length of 3000 mm (118"):
l = 14.4 mm (9/16")
Change in width (w) for a sheet with a total width of 1000 mm (39.4"):
w = 4.8 mm (3/16")

Assuming an installation temperature of 20°C (68°F), the total movement—expansion/ contraction—of the individual sheet elements is:
Expansion Δt = 25°C (77°F)
l = +6.0 mm (1/4")
w = +2.0 mm  (3/32")

Contraction Δ t = 35°C (95°F)
l = -8.4 mm  (21/64")
w = -2.8 mm  (7/64")

Change in length over entire temperature range:
l_total = 14.4 mm  (9/16")
w_total = 4.8 mm  (3/16")

The temperature during installation is to be taken into account and the expansion joints to be located accordingly.