Practical advises
The purpose of the wooden listels, disposed like support of the roofing tiles of each type, is to consent the necessary perspiration of this important element of the habitation. In the big part of the cases the under tile structure is a floor in cement with relative stone in concrete and either the tiles are simply leaned to it. This habit, that is not advisable, doesn’t provoke problems neither for the capacity nor for the length of the roof, to condition nevertheless that between the roofing mantle and the floor there is sufficient ventilation. It is inadvisable the use of the mortar for the locking of the tiles, because it works like absorbent of the humidity. The tiles have to be free or fixed with nails or screws.
The setting-up of the Marsigliese tile is on horizontal lines leaving from the eaves. We produce two kind of Marsigliese tiles, one that permits the assembly of the lines either in line or staggered, the other that obliges the assembly just in staggered lines. Between the two solutions there is just the aesthetical choice and the assembly choice, because the quality and the flowing of the water is guaranteed in both of them.
The Marsigliese tile that permit the assembly just in staggered lines (for distinguishing these type we will call them “Old Type”) are suitable to the restoration of old buildings and consent solution to the old manner.
The setting-up of the Portoghese and Olandese tiles is equal and we can carry out it on vertical lines, aligned in the sense of the slope, after having disposed a line of tiles along the eaves line.
Every three or four lines is advisable to check the alignment of the tiles. The external border of the tiles has to appear raising about 2 cm. We can obtain it laying an ulterior thickness (wooden listel) in way that we don’t have, respect to the superior line, different angles.
Every kind of tiles are superimposed one on the other with a double joint vertical and horizontal, in way that we can attenuate the passage of the air in case of strong wind, while it is impeded the infiltration of the water also in conditions particularly difficult.
In case of the romana roofing (tiles and hollow tiles) the course is evidently dictated fro the form of the element: we placed the flat tiles on the floor and we put on horse the hollow tiles taking care of the uniformity of the alignment and the opening of the elements.
The eave tile is of rectangular form, smooth and usually it is walled up. For obtain the best chromatic effect we suggest a particular care in the stage of the setting-up of the tiles.
The slope
Normally the slope of the roofing in brick is of the 30%, but some particular conditions ask slope more strong above all in area where there is a strong wind or altitude, or snowy area or a lot of precipitations. Good rule is following the local system. Conditions particularly favourable can consent roofing with sloping lower then the 30%, but the right sloping consents a better flowing of the water and removes possible infiltration between tiles and tiles caused from the wind.
Fixing of tiles
Generally the tiles have a hole for being nailed on the listels or on the floor. Our tiles have also in the back a drilled nib in which we can pass a steel wire for fixing them to the listels.
The eaves
This particularly area of the roofing, missing an adequate ventilation, can be interested from the formation of water for the dissolution of the snow and of the ice, on that account the part of the cornice that is projecting and the perimetric fillet (about 1 meter) immediately upstream is good that it will be protected by means of a waterproofing scabbard.
The ventilation
We have already said about it previously but it is opportune fixing some concepts. The brick tiles are not waterproofing: they have in fact a micro porosity that consents them of imbuing themselves of water during the rain, but then, for the climax effect, the water and the humidity evaporate and we can establishing again the natural state of the roofing. This occurs when we produce a right ventilation of the lower face of roofing mantle and we favour the formation of the up-current that leaving from the eaves line rises up along places specially created, until the roof-ridge. It is good specify that the micro porosity of the brick that we have said above doesn’t diminish in any way the capacity of the water, but it has positive effect for the thermo hygrometer welfare, the movement of the air that is formed consents the preservation of the same temperature on the two surface, lower and upper of the tiles mantle, avoiding sudden change in temperature, while assures in the summer period a good defence against the solar radiation. For procuring an easy circulation of the air (every 25 mq of roofing, with a minimum of aerator for every pitch independently from the surface of the pitch itself). It is good to stagger the aerator situated near the eaves respect to these situated near the ridge for favouring a trasversal movement of the air and avoiding preferential distances. To completion of our suggestions about the necessity to not forget the importance of the aerator, we inform that exists an alternative to the wooden listels that is this of creating string-course of mortar interrupted every two meters for consenting the passage of the flow air.
