Built-in Roof: Cost, How to Do it – See Several Houses!
You have certainly seen a property with a built-in roof. The option is increasingly common in construction, as it makes the building look cleaner, with straight lines. This is because, instead of the apparent tiles, this type of roof hides the roof of the property behind platibands.
The plateau is a small wall built on top of the building, a kind of small wall that hides the roof just behind. Its height is variable: when smaller, it tends to be more delicate, while the tallest ones promote a sense of grandeur.
For the built-in roof project to be well-executed, it is necessary to think about how many waters it will have. The waters of this structure consist of the flat sloping surfaces of the roof. They are responsible for ensuring the flow of water. If they did not exist, the rain would accumulate on the ceiling, causing infiltration and shaking the entire support of the property, since the load on the slab would be much greater. Thus, to say that the roof has, for example, two waters means that it has two low areas.
Compared to other options, this type of roof is cheaper. It also has simpler execution, optimizing the execution time of the work. As it is lighter, it also demands less capacity from the foundation. This means, for example, that it is possible to take advantage of a cheaper foundation, such as the radier (find out about the alternative in this text ).
In any case, it is important to verify the need to install a thermal blanket. Especially for hot climates, the element will be essential to keep the internal temperature of the property comfortable.
Structures of embedded roofs
Compared to the exposed roof, which is more common, the recessed roof has basically the same structures. However, its execution is more simplified, as well as diversified – after all, the structure can be made of wood or metal, at the choice of the architect and/or client.
The composition of the frame includes four main components: scissors, gutters, rosaries and flashings. Scissors are the triangle-shaped structures that lie below the roof. They are responsible for supporting and distributing the weight of the roof to the slabs, ensuring their proper support.
Scissors are composed of the line, stirrup, hat, pendulum, diagonal and leg. Generally, one is positioned every two meters, but this can vary according to the project of execution of the work.
Tuesdays are responsible for connecting the scissors and distributing the weight of the tiles to them. They are metal or wooden beams, to which the tiles are directly attached. The process is simpler than normal, because on a common roof it is necessary to use rafters and slats for this fixation.
As mentioned, the slope of the tiles is essential to guarantee the flow of rainwater. However, the liquid is not directed directly to the floor, but to the gutters installed around it. As soon as they collect the water, then the pieces send it to the ground. The gutters are available on the market in galvanized steel or PVC.
Finally, metal flashings are used to join the tiles and the plateau, avoiding the accumulation of water in the corners of the slab.
Step by step how to make the recessed roof
If you want to ensure that your slab will be perfect, it is essential to have an architectural project made by a professional. Only an engineer or architect can indicate all the technical specifications, measures and materials necessary for the execution of the project. You can also check if this type of roof is really the most interesting for the property in question.
When assembling the roof, it is necessary to be careful with the placement of each element mentioned above. Starting with the scissors, which must be aligned and straight. Tuesdays should be installed with equal spacing, according to the type of tile that will be used. Each tile requires a different spacing, as indicated by the manufacturer.
It is also the manufacturer who indicates the best way to install the tiles. Corrugated pieces, for example, are easier to position if they start to be done in the corner of the lower part of the roof.
In addition to the elements mentioned so far, it is also interesting to use the ridges. The pieces need to be fixed in the meeting of the waters, that is, of the roof slopes. They prevent the infiltration of the property. The gutters also deserve special attention, being well fixed. They must withstand all the water that comes from the rain, without allowing the accumulation of liquid to occur, even if there is a strong storm.
Which tile to use on the built-in roof?
In general, any tile can be used on a built-in roof. Three, however, are the most commonly indicated: fiber cement, polypropylene and metal.
Asbestos cement tiles are the most economical, both in terms of money and in terms of the execution time of the work. This is because it is available in large plates, which cover a large area in one go. They can be straight, wavy, trapezoidal and of other shapes, being your choice made according to the design of the engineer and the inclination of the roof. After all, the slope obtained with this type of tile is small, between 15% and 20%.
Polypropylene tiles, on the other hand, have varying sizes. Thus, they can cover a large area at once, or they can be used for small spaces. Its main highlight is that it is translucent, that is, it allows the passage of part of the natural lighting to the interior of the property. Therefore, it is important to use them only if this is the consumer’s objective.
In any case, polypropylene tiles can be combined with ceramic, fiber cement or other tiles. This means that it is possible to guarantee natural lighting only in one part of the house, and in the rest to have a common slab.
Finally, the metal tile is the best option when you want to imitate rows of concrete or ceramic tiles. Its resistance is enormous since it is produced from galvanized steel.
Built-in versus apparent roof
It is common for the consumer to choose between a recessed roof and an exposed roof, checking only the visual characteristics of the options. That is, for a more classic look, exposed tiles are the alternative; for the cleanest decoration of the facade, the recessed roof is the solution.
For the determination between the two options, however, it is interesting to evaluate other advantages, as well as disadvantages, of each product. Execution time and expenses are the main aspects to be considered. Follow the information!
1. Recessed roof: advantages
The first advantage of using a built-in roof is that the construction uses a small amount of wood to support the slab. After all, the tiles are usually lighter, requiring less support. This lightness, in fact, reduces the expenses with the foundation of the building.
Roofs with non-visible parts are also easier to build, requiring less manpower and time to complete. In addition, there is the incredible visual provided by it, with modern and lighter airs.
2. Recessed roof: disadvantages
For those who are not adept at this type of roof, one of the main reasons is the height of the slab. It is usually smaller, as it must be hidden in the back of the stands. This characteristic makes access to the interior of the slab very difficult for the electrical, hydraulic or other maintenance that may be necessary.
Despite the aforementioned advantage of the financial economy, it is necessary to consider the higher spending on gutters and platibands. Especially since the number of water outlets is higher in this coverage configuration. In the case of the use of fiber cement tiles, the expenses can also increase, since it is necessary to install a thermal blanket under the tile.
3. Apparent roof: advantages
Among the main advantages of an apparent roof is its durability. Not that the built-in roof is not resistant and durable, but ordinary clay tiles have incredible firmness.
Its aesthetics are equally pleasant, and can be easily adapted to the consumer’s decoration objective. This since there are numerous types of tiles available on the market. In addition, the pieces are heavier, so they are unlikely to come off in strong winds.
4. Apparent roof: disadvantages
Speaking of the disadvantages of this type of slab, there is a high cost. This is because, the weight of the items demands a greater support structure, which uses a lot of wood, cement and other materials. The execution of the process is also slower, since it is necessary to fit tile by tile on the surface.
How to calculate a built-in roof?
The calculations of an embedded structure are simple, but they must always be performed by a trained professional. Ignorance of technical information can damage the entire installation, and generate risks of collapse. For this reason, do not “venture”, nor let a bricklayer, even if trustworthy, venture into the project. Hire an architect or engineer to design the plan.
One of the calculations performed by the professional will be to find out the amount of scissors needed in the structure. As mentioned at the beginning of the text, it is common to have scissors every 2 meters of structure. Therefore, the total length of the construction must be divided by two – the result will indicate the minimum number of scissors for the installation.
The thirds can be calculated by the following operation: (width of the building + eaves of the property ) ÷ spacing of the third. The result must be multiplied by the length of the construction. Thus, it will be possible to obtain the measurement of beam linear meters for the thirds.
To determine the amount of tiles needed, you need to know your yield per square meter. The information is provided by the product manufacturer. Finally, the number of ridges required for construction is obtained by multiplying the length of the property by the yield of the ridge. This yield is also reported by the product manufacturer.
Recessed roof: slope
All the execution of the works of embedded roofs must follow specific norms of ABNT (Brazilian Association of Technical Norms): the norm NBR 15575-5: 2013 – Housing buildings – Performance – Requirements for roofing systems; a NBR 13858-1: 1997 – Concrete tiles – Roof design and construction; and NBR 7190: 1997 – Design of wooden structures. Only with these specifications is it possible to obtain a well-made and safe slab structure.
One of the information available in these technical standards is the necessary inclination of the built-in roof, so that rainwater is properly drained. What determines the slope is the type of tile used, as each of them requires a different measurement. The information must be provided by the material manufacturer. Generally, it provides the minimum and maximum pitch for roof installation.
In any case, this inclination is measured in percentages, and it is important to know how to “read” the information. A roof with a 10% slope, for example, will have the following configuration: every 100 cm (1 meter) horizontally, the roof must rise 10 cm vertically.
This measure corresponds to the following: 10% is equal to 10 over 100 (10/100). The first number corresponds to centimeters vertically, while the second is measured in centimeters horizontally. In the case of a roof with a 20% slope, every 100 cm horizontally, the roof should be 20 cm vertically, and so on.
AQ – Questions and Answers
Which gutter to use on the built-in roof?
In the built-in roof the installation of gutters must be part of the structure, because without them there is no way to drain the water from the roof to the ground and avoid damage to the structure. The gutters can be made of pvc or galvanized sheet, with the function of collecting and directing rainwater to the terrain.
Several pictures of built-in roof