Wall packages are becoming thicker due to stricter insulation standards for new buildings and renovations. This has a direct impact on the construction of eaves in flat roofs, which therefore become wider. This increases the importance of the stability of the plywood or concrete plywood used.
The wider the slab, the faster any degradation becomes visible, especially under the influence of stormy weather. Beginning decay can cause the top layer to become loose due to high winds.
We see an example at a home that weathered a storm shortly after completion. The wall package consisted of EPS insulation with a crépi finish. The only stability came from the aerated concrete top layer of the interior wall, with a wall cover about 45 to 50 cm wide.
Where it went wrong: A panel with wood species of durability class 5, such as poplar, eucalyptus and birch, was chosen. Due to incipient rot, the eaves came loose, leading to damage to the crépi siding.
(To be sure: No Solid John Concrete Plywood used 😉)
It is crucial to both the panel quality if the fixing method emphasize. Skirted mechanical attachment to the interior wall is strongly recommended.
Placing screws in one line should be avoided, as this makes the eaves vulnerable to weathering, regardless of the quality of the panel.
In this particular case, L-irons for additional support had been installed, in accordance with WTCB guidelines. However, these provided little help as the panel began to rot shortly after completion.
