Self-fitting sheet metal - Piano
Piano self-fitting roof and façade sheet metal is a relatively new product in our market, and it has acquired its excellent reputation throughout Europe long time ago already. Because of its exquisite characteristics and universality in application, but first of all because of its exquisite appearance, it becomes standard in our country, too. According to its appearance, Piano reminds the most of classical notched sheet metal and actually it is a considerably advanced solution of the same.
Special convenience of Piano self-fitting roof and façade sheet metal is the possibility of application in large number of various roof and façade substructures.
The assembling can be carried out in single layer, on level slab or roof laths, as well as in two layers, in combination with trapezoidal sectioned sheet metals. Modern and innovative section enables the installation of complete roof and facade without any visible screws, which is very often requested by the employers. Elegant strengthening along the section length gives it effective appearance.
Piano roof covering can be applied in roofs with inclination not less than 3%. In roof sheet metal variant, Piano can be laid on level substructure – board or lath. Before assembling roof sheet metal, vapor transmission – waterproof sheet is laid, fastening of roof section is carried out at each 30-50 cm. Before assembling, the roof angle is checked, that is, it is established whether the roof structure is set at the angle of 90°. In the case that roof geometry is not good, it is necessary to establish the magnitude of deviations, on the size of which the manner in which these deviations will be corrected depends, either by lateral cutting or by small corrections in the joints between the slabs.
Assembling of single layer roof sheet metal
In the case of covering with only one layer of sheet metal, the laying of boards over the whole roof slab is recommended, although that is not the precondition. Sheet is placed on roof slab covered with boards, and then the roof slab is covered with laths by placing of longitudinal laths and transverse laths over them at 30-50 cm distance. Piano can be also assembled directly on sheet, without previously laying the laths. Also, assembling can be carried out on prepared steel substructure.
Longitudinal joining of plates is necessary if the customer for certain reasons decides that the covering is carried out with two or more plates in one vertical series. At roofs with inclination less than 8 % (1:7), the overlapping should be minimum 500 mm. At roofs with inclination larger than 8 % minimum overlapping between two plates is 250 mm.
Roof and façade sheet metal in sandwich execution
Except covering or lining of façade with single layer of sheet metal, assembling can also be carried out in sandwich execution with thermal insulation. The roof or façade structure in that case is following:
1. Internal sectioned sheet metal
2. PVC sheet (Vapor barrier)
4. Thermal insulation
5. Vapor transmission and waterproof foil
6. External sectioned sheet metal
Gutter with gutter batten
As with other roof coverings, the assembling begins with gutter and gutter batten which closes the space between the gutter and the roof sheet metal.
Wall batten is laid at the places at which the covering material comes directly beside the wall. Its role is to protect from water penetration into the building interior, that is, to prevent dampness of the walls, and to collect precipitation and conduct it to the gutter. The laying of the wall flashings is carried out after assembling of the roof covering.
The basic functions of the wind battens are protection from the wind action on lateral sides, protection of purlins with flashings and aesthetic function. The wind batten is assembled after assembling of Piano roof sheet metal.
There are several models of saddles for roof sheet metals, which differ according to appearance and the manner of assembling. As standard, there are saddles which are placed flatly on the sectioned parts of Piano section or ridge tile is cut so that the ridge cut leans on the sectioned part.
|Sheet metal thickness:||0,5 mm – 0,8 mm|
|Sheet metal width:||625 mm|
|Profile width:||475 mm|
|Length:||depending on transportation (12 000 mm)|
It is made of galvanized coated sheet metal. Colored aluminum and copper are also used upon request.
Available in all colors from the RAL color chart
Substructure preparation and checking
For good quality and functional roof, it is necessary to prepare roof substructure with good quality, which implies laying of boards over complete roof slab and placing of roof, vapor transmission waterproof sheet, which ensures correct roof structure ventilation. Beside that, it is necessary to place longitudinal (vertical) and transverse (horizontal) laths.
The manner of placing laths at regular distances and arrangement is presented in the figure. Minimum height of longitudinal (vertical) lathe is 12 mm while for transverse (horizontal) laths the standard dimension used is 30x50 mm (minimum 25x50 mm). It is very important to entirely comply with the arrangement of laths.
Check whether the roof substructure is set at the angle of 90°. If that is not the case, it is necessary to level the first slab with eaves, and to cut off the lateral part of roofing tile slab and level it with the roof structure.
Assembling of roof sheet metal and accompanying elements
Gutters with gutter batten
Gutters serve for draining of precipitation waters from the roof, and gutter batten closes the space between the roof sheet metal and the gutter. The hooks are assembled first, but the hooks should be adjusted in such manner that gutters have the appropriate inclination, then the gutter is assembled and finally the gutter batten.
Wing batten has the function of protecting the roof sheet metal from the action of lateral winds, as well as aesthetic function. The assembling is, depending on the type of wind batten, is carried out before or after assembling or roof sheet metal.
Wall batten has the function of wall protection at the places at which the roof sheet metal comes directly beside the wall, as well as preventing of water penetration into the building interior, and conducting of water to the gutter. Depending on the type, wall batten is assembled before or after assembling of roof sheet metal.
Roof valley can have the function of gathering and draining of precipitation waters, and also it can function as the gutter. Roof valley is assembled before assembling of roof sheet metal.
The function of chimney flashing is the same as the function of wall flashing. Chimney flashing is assembled in the phase when roof sheet metal is also assembled.
Roof light comes with already prepared flashings, so that the window is assembled simply. Roof light flashing is as standard in the color of the roof sheet metal.
In the case that mansard roof is in question, roof sheet metal is assembled first on façade part, then flashing batten is assembled, and after that the roof sheet metal on the roof.
Assembling of roof sheet metal in the form of roofing tile
Roof sheet metals in the form of roofing tile are as standard delivered in slabs, the length of which is equal to the length of roof slab. In the case that the length of the roof slab is large (more than 7m) it is recommended that the roof sheet metal slabs are made in 2 or more parts, but it is necessary to add 100 mm for each overlapping to the length of slabs. The overlapping slabs should have regular beginning and end (n roofing tiles x 350 mm + 100 mm for the beginning and end of roofing tile).
Roof sheet metals in the form of roofing tile are longer by 70 mm from the length of the roof slab. That part of sheet metal is toed from the eaves to the gutter, which should be borne in mind when ordering and assembling of sheet metal.
Here we attempted to present somewhat more complicated variant of roof, roof with several saddles with numerous slopes of various shapes.
Roof sheet metal assembling - type A
After assembling of flashings which are placed below the sheet metal is finished, assembling of roof sheet metal can begin. The covering is as standard carried out from right side to the left (looking from the eaves to the ridge tile). Special attention should be paid to the assembling of the first slab, which must be leveled with the eaves, and if the roof structure is not set at the angle of 90°it is necessary to cut off the first slab at lateral side in order that roof sheet metal might be level with the structure, too.
Roof sheet metal assembling - type B
Kod ovakvih krovnih ploča prvo se montiraju duže ploče a zatim kraće.
Shorter slabs must have regular beginning and end (n roofing tiles x 350 mm + 100 mm for the beginning and end of roofing tile). After the shorter slabs are assembled, too, if they are passing over the eaves by more than 70 mm, it is necessary to cut down the same on the eaves.
Roof sheet metal assembling - type C
With this type of roof slab, it is important to take care that all roof sheet metal slabs which are placed at the slope have regular beginning and end (n roofing tiles x 350 mm + 100 mm for the beginning and end of roofing tile).
When assembling, the slabs which are placed at the slope are cut in the lower part and adjusted to the roof structure shape.
Roof sheet metal assembling - type D i E
With such slab it is necessary to assemble the longest slabs first, and than the slabs on the slopes, which it is necessary to cut down obliquely so they may follow the shape of the roof structure.
Assembling of roof sheet metal on the roof slab with dormer and chimney
With such slab, the assembling begins from the right side, and at the places at which the roof slabs are beside chimney or dormer, lower roof slabs are placed first. After that, the slabs are cut according to the shape of chimney or dormer and are assembled. It is important to mention that before assembling of roof sheet metal it is necessary to assemble the roof flashings.
Assembling of saddles is carried out the assembling of roof sheet metal is finished. Before saddle, section filler is placed, although the saddle can be also placed without the filler. The saddles are fastened through roofing tile rib with SVP type screws 70 mm long (4 pieces/m of the saddle).
The function of snow barriers on the roof sheet metal in the form of roofing tiles is performed by standard snow barriers. Snow barriers are fastened through roof tile rib with SVP type screws 70 mm long.
The quantity of snow barriers depends on the roof slab length, roof inclination and climatic conditions. Minimum 2 rows of snow barriers should be assembled on roof slabs up to 6 m long, and minimum 3 rows on roof slabs more than 6m long (or 4 rows in zigzag arrangement). The arrangement of snow barriers on the roof is presented in the figure.