One of the solutions for exterior finishing is using wood. After placing the OSB panels on the profiles, a whacked is placed. The thermal insulation can be applied between the whacked. Over the whacked it is possible to apply solid wood with 20mm and a varnish with stain.
The Cappotto (aka capoto) is one of the most commonly used insulation solution. However, it is essential to consider some factors such as:
1. Thickness and density of the Boards
The thickness of the polystyrene boards should be greater than 3 cm thick, for refurbishment, and between 5 and 6 cm for new works. It is not recommended a thickness below 3 cm, because the polystyrene boards can deform after some time. On the other hand, it is also not advisable to use polystyrene boards with more than 6 cm thick, once the minimum temperatures in Portugal are not so low that justify investment.
Note that the density of polystyrene plates for residential uses should 20kg, and it is not recommended the use of material with lower density.
2. Begining of the works
At the start of the work is essential to define the techniques and procedures to follow, since this phase will influence the success or failure of the work. Thus, all capoto works should start with fixing starter gutters that will support the polystyrene plates, preventing them from getting uneven and rodents, moles or other animals, sticking the boards or enter the premises.
3. Fixing the plates
The fixing of polystyrene plates is one of the most important process for customer satisfaction because if they are poorly fixed, after some time they will give in and detach. Thus, for a good fixation, they should be glued with special glue and then fixed to the surface using screws and plugs specific for capoto, at a ratio of 8 units per m2.
4. Net and Mortar
The application of the capoto net and mortar is very important to avoid the subsequent arise of cracks. The net to be used should be made of fiberglass and not of plastic, as it is usual, because it does not break.
The mortar used for attaching the net must be specific for the purpose. It should not be used the typical glue for fixing plates. It should be carried out a first application of the mortar, then the application of the net, and only after drying it should be held to a second application of the mortar to regularize the “honeycombs” created by the net application.