How to choose a Roto roof window - a detailed step-by-step guide

How to choose a roof window and enjoy the result for years is the client’s first question before purchasing. Installing and replacing skylights is a long-term investment, so buyers are looking for detailed information about roof glazing. We have prepared a detailed step-by-step guide and recommendations from roofers for choosing and planning natural lighting in the attic.

What determines the size of the attic window?

The dimensions of the products are determined by a number of factors; First of all, the size of the windows on the attic roof depends on the role the room plays. If this is a bedroom, the windows may be small; for a living room or children's room, on the contrary, stronger lighting is required, so you need to install larger windows.

The sizes of roof windows can vary. But most often there are models on sale that have standard dimensions of 94 or 114 cm. Windows of this type can also differ in the design of the double-glazed window, the method of opening, the location of the handle, etc.

If for a sleeping room we can base it on the calculation of 1 meter of glazing per 10 meters of floor, then for other types of rooms a standard of 1 to 8 is required. There must be at least one window if the attic is small. If the roof structure allows, you can install one large window, but with a standard rafter system, you will need to install several frames. You also need to remember about ventilation, so at least one window should open.

Determining the size of windows depending on the area of ​​the room

Glazing standard

Artificial light cannot always replace regular daylight. Twilight is dangerous to health. If you constantly strain your eyes, your vision will deteriorate over time. Therefore, government regulators have developed standards for glazing.

SNiP 31-01-2003 gives the following instructions: in low-rise buildings with inclined glazing, the floor area should be in relation to the window area as 10:1 .

What does it mean? For every 10 m2 of flooring, at least 1 m2 of glass must be installed. Let's give an example.

The length of the floor part of the attic in the house is 6 m, and the width is 4 m. First, let’s find the total area:

6 × 4 = 24 m2.

Now let’s calculate how many squares of windows are needed:

24 / 10 = 2.4 m2.

It turns out that for vision to remain normal, 2.4 24 m2 of floor .

How should the windows be located?

If you plan only two window openings, then it will be most convenient to place them opposite each other. This will allow you to get brighter lighting, and its duration will be longer, since the sun changes its position during the day. Most often, a roof window is used, the width of which does not exceed the width of the rafters. The frame should be slightly narrower, which will allow it to be placed between the rafters without disturbing the roof structure.

Before installation, you should pay attention to the direction of the world: if the window faces east, it is not very convenient for the bedroom. The south side will provide good lighting, but the room will be hotter, so you may have to use tinting film or it is better to make a window facing the other side. The length and height of the structure also plays a role. The height should not be less than one meter, and the window should be located no lower than 90 centimeters and no higher than 1.3 meters from the floor.

Height of roof windows

When choosing a structure according to length, the angle of inclination of the roof is mainly taken into account. This parameter has no other restrictions; The greater the slope, the shorter the window can be, and vice versa. This will create optimal lighting. For example, if the angle of inclination is 35 degrees, then it is best to choose windows within 160 cm; with a strong slope of about 70 degrees, the best option would be structures whose length does not exceed 120 cm.

Roof window length: vertical section

In order to choose the width, you need to know how far apart the rafters are from each other. To do this, you can use project documentation or measure with a tape measure if the rafters are not hidden under the finishing. It is highly not recommended to interfere with the rafter system, as this can significantly weaken the roof and even lead to its collapse. That is why windows are selected in such a way that they fit between the rafters.

Layout with an additional vertical window

Dimensions of opening doors

Movable sashes in window units mounted in the roof pie are made with fixed dimensions, which depend on the mass of the movable element and the permissible load on the fittings.

For typical dormer window structures, with a mid-turn or swing mechanism, the dimensions of the sashes are as follows :

• 
  For window blocks 550 x 780 – 460 x 690 mm.

• 660 x 980 – 570 x 790 mm.
• 780 x 1180 – 690 x 1090 mm.
• 940 x 1180 – 850 x 1090 mm.
• 940 x 1400 –850 x 1310 mm.
• 1140 x 1180 – 1050 x 1090 mm.
• 1340 x 980 – 1250 x 890 mm.
• 1140 x 1400 – 1050 x 1310 mm.

If it is necessary to install sash windows of other dimensions into the fixed frame frames of a window, it is recommended to manufacture custom-made structures with the installation of standard double-glazed windows. In such cases, to increase the safety of facility owners, it recommends installing such translucent elements, provided that the slope of the rafters exceeds 35 degrees, which eliminates the formation of snow bags and the occurrence of increased loads in winter.

Does the size of the structure depend on the manufacturer?

The standard sizes of attic windows from different manufacturers can differ significantly from each other, so before purchasing you need to study the parameters of each window you like. For example, it is almost impossible to find small Velux windows: the manufacturer focuses on large and medium-sized structures. The smallest model can be called, the size of which is 55x98 cm, the largest window that the company offers is 114x140 cm.

Fakro windows can be selected slightly smaller than 55x78, the largest window is 134x98. Most of the manufacturer's models are medium in size and are quite suitable for different attic floors. Roto windows are very popular. The smallest designs have dimensions of 54×78 and 54×98; you can choose a medium-sized design. However, you should not try to look for large windows: the manufacturer practically does not produce them.

Standard sizes of roof windows

Types of triangular windows

Plastic and wooden triangular windows can have a large area, however, when glazing large openings, it is recommended to divide such structures into separate blocks. As for the geometric shape, these models are most often:

• rectangular;
• isosceles.

Products with cut off corners are also manufactured. They are also called triangular, but in fact the number of angles in such structures can be four or six. Most often, windows are selected depending on the roof structure and the location of their integration. Rectangular models are installed under the roof slope, and isosceles or equilateral models are chosen for dormer or dormer windows. The doors of these structures can move in different directions. The method of opening such windows depends on both the shape of the triangle and the features of the binding. There are currently several options available:

• hinged
  - suitable for rectangular models in which the sash is hung on the vertical side of the frame;
• tilting
  (fanlight) - considered optimal for windows in the shape of isosceles or equilateral triangles, however, it is theoretically possible to hang a tilting sash on the lower side of a rectangular frame;
• tilt and turn
  - applicable for rectangular models with a vertical side of the frame on which the sash is hung.

At the same time, for all types of triangular windows, a blind version is possible, when the structures do not open at all. If the area of ​​the opening allows it to be divided into several sections, then it becomes possible to integrate a rectangular sash with a tilt-and-turn mechanism.

Individual order

In order for the design to fit perfectly, it can be ordered from the manufacturer. They will make a window for you according to the required dimensions: this is the most optimal way, in which the frame will exactly fit in width and length, it will be possible to take into account the features of your roof and all your wishes. However, there are some limitations in the ability to order the desired design. Any manufacturer can produce only six window options, taking into account width and height. Windows can be rectangular and have only one sash. However, it can open in different ways; The opening method is related to the fittings used.

Before ordering a roof window, the size of the opening must be carefully measured. The width is measured from rafter to rafter, and the length is measured by the size of the roof slope on the inside of the room. It cannot exceed the length of the slope, since the window should not extend beyond the roof.

Many manufacturers have 6-14 standard window sizes, which in most cases are suitable for a particular rafter system. However, you can order according to your dimensions, but the dimensions of the window may be limited by the characteristics of the materials and equipment used. Thus, it is unlikely that the manufacturer will be able to produce a window smaller than the minimum size or larger than the maximum.

Table with standard indicators

How to choose a manufacturer and brand?

Once the choice of window sizes has become clear, it is worth moving on to an equally important issue regarding the choice of manufacturer, because roof windows are produced by a large number of companies. In order to choose the right product, you need to consider the following:

• Number of functions. The more there are, the more expensive the window will be, but not always after purchase all the available window capabilities are used, so you should not overpay for unnecessary options. Be clear about what you need and what you don't.
• It is better to buy from a manufacturer whose name is well-known. You can read reviews on the Internet. In order not to overpay, it is worth finding the company itself or its regional representative, because intermediaries mark up up to half the cost of the product.
• Find out what sizes the company produces and whether there are ready-made windows in the sizes you need. If there are no finished products, it would not be superfluous to find out whether it is possible to manufacture a window with the required parameters and how long it will take.
• Feel free to ask for price. It may depend not only on the brand, but also on the quality of the profile, the fittings used, and the dimensions of the structure. Manufacturers often hold various promotions and provide discounts, so there is a chance to purchase a design cheaper.
• Take a close look at the profile; the manufacturer should have samples in the office; If the plastic has no voids, no foreign smell, and is attractive in appearance, you can trust your own opinion.
• Please note that if the dimensions of the skylights are standard , the finished products are slightly cheaper than non-standard ones, which will have to be specially ordered. This is due not only to the mass production, but also to the basic settings of the equipment.
• It is worth remembering that roof windows, like ordinary ones, differ in technical characteristics. There may be a different type of plastic, the thickness of the glass unit may differ, and the glass itself may have different properties. All this is taken into account individually, since the requirements for a window may differ significantly from one client to another.

Standard sizes of roof windows Roto, Fakro Velux

Location of opening elements

The opening axis is located in three variations: in the center, along the top and at 2/3 of the height of the window itself. The central option is very popular, since its installation is recognized as the most inexpensive. The two remaining options have the common advantage of convenience and comfort, eliminating the possibility of accidentally hitting an open window. Do not forget that if you wish, you can always choose a combined opening system.

Most often, windows with a central axis are installed

Installation Features

Installing roof windows is not difficult, however, it requires some knowledge and skills, so if you do not have any experience, it is better to entrust the work to professionals. If the window is installed incorrectly, there is a risk of freezing, drafts and condensation. If the window is chosen correctly and its quality is high, then if installed incorrectly, all its positive properties can be negated, especially since windows installed in the roof can leak if they are not provided with adequate waterproofing.

When purchasing a window, make sure that the manufacturer includes a warranty. Professional companies do the installation themselves and provide a guarantee on the work. If you use a third-party company, also make sure that the warranty on the work is documented. This will help avoid problems if the window is delivered incorrectly.

When the width and height of the roof window are chosen correctly, the structure is purchased from a reliable manufacturer and installed correctly, there will be no problems with operation. The window will be sufficiently airtight, will allow you to turn the attic space into a living space, provide sufficient lighting and allow ventilation.

Regulatory regulation

The dimensions of window units intended for installation in the roof pie are regulated by the following regulatory documents :

• 
  GOST 30374-2000 “Wooden attic window blocks”.

• GOST 30374-2020 “Attic window blocks”, updated edition.
• STO NOSTROY 2.23.62-2012 “Translucent fencing structures. Window".
• GOST R 56926-2016 “Window and balcony structures for various functional purposes for residential buildings.”
• GOST 21519-2003 “Window blocks made of aluminum alloys”.
• GOST 23166-2021 “Translucent fencing structures for windows and balconies.”
• GOST 34378-2018 “Translucent enclosing structures. Windows and doors."

Based on regulatory documents, each manufacturer operating on the Russian market draws up technical specifications. After testing prototypes of products, each model receives a certificate of compliance with technical specifications, which indicates the high quality of window units.

Do-it-yourself mansard roof: installation procedure

The design of the Mauerlat on mansard roofs is no different from the standard version. If the house is made of timber or logs, the upper crown can be used as a mauerlat. It is only pre-treated with impregnation with high protective properties.

If the wall is made of foam blocks, a reinforced monolithic belt is placed on top of it. On a brick wall or made of shell rock or other similar materials, the installation of such a belt is not necessary. Waterproofing is laid in two layers on the wall, and on top is a timber treated with an antiseptic - 150 * 150 mm or a log. It is secured with embedded studs.

How to attach the mauerlat and rafter legs to it

When assembling all elements, long nails are used - at least 150 mm long. In the most critical places, it is better to connect three or more elements using bolts or studs with double-sided threads. It is advisable to strengthen all joints with steel plates or corners.

You can read about building a house from aerated concrete in this article.

First way

Installation of attic roof rafters is done in two ways. First: they assemble the parts on the ground, then lift them up in finished form. There, the outer structures, which will become pediments, are put up first. They are placed vertically and secured. It is often more convenient to secure them with long bars nailed to the wall (temporary). The following assembled structures are inserted into the prepared recesses in the Mauerlat (they are made at the required pitch). They are positioned strictly vertically and carefully secured. If necessary, additional temporary spacers are installed to fix them in the desired position. Side beams are installed.

How to build a sloping roof in this way and assemble the nodes, see the video below.

Second way

The second method - the construction of a sloping roof is carried out sequentially by assembling elements directly on site. This method is more convenient if the structure is large and when assembled it can only be lifted using special equipment (crane).

First, the floor beams are laid. Stands and ties are attached to them, and temporary spacers are installed to hold them in the vertical direction. Next, the upper and side rafter legs are assembled, and the tie rods and jibs are installed.

During installation, the following sequence of actions is observed: first, the outermost elements are installed and adjusted to the desired position, and securely fastened. If necessary, use temporary spacers. A fishing line, rope, and cord are stretched between them, which will serve as a guide for the installation of all subsequent elements. This simple move allows you to get the ideal geometry (don’t forget to check the slope angle, verticality or horizontality).

On top of the racks, tie-downs are attached - bars, to which the side rafters are then fixed and onto which the tie-down of the upper triangle is installed. The ties are secured using metal corners. Since the beams are long, they sag. This is later eliminated - after installing the upper rafter legs - with the help of vertical beams of fixed or adjustable height. And temporarily they can be supported with racks (so as not to pull the entire system).

One of the stages of building a mansard roof with your own hands

To make it easier to maintain the desired angle when installing the side rafter legs, templates are made according to which cuts are made. But since the geometry of buildings built with your own hands is rarely ideal, adjustments may be necessary. To check the resulting angle of inclination, another template is knocked down from several boards, which is used to check the correct installation.

If the standard length of lumber - 6 meters - is not enough, either order the required length (expensive) or increase it. When building up, two boards measuring at least 0.6 meters (30 cm on each side of the joint) are nailed to the joint. They are nailed on both sides or bolts are used.

A reliable way to build rafters. The length of the “patch” is at least 60 cm

After installing the side rafters, all that remains is to install the top ones. A template is also made for them, pre-cut on the ground, and installed on top.

Almost finished frame

The top part can be made in different ways. Its structure depends on the width of the base. How to make it, look at the photo below.

How to make an upper triangle on a sloping roof

Since the structure of the attic sloping roof does not provide for the presence of a ridge, a beam is placed in the middle to tighten it, to which the slopes are attached, fixing the triangle in the required position.

The upper part is fixed with bevels nailed to a beam laid in the middle

In this case, we can consider that the attic roof was assembled with our own hands. All that remains is to install the roofing material and do the insulation (you can do it in that order, you can do it at the same time). Features of insulation of attic roofs are described here.

Nodes and their drawings

When installing a rafter system, questions may arise regarding the assembly of nodes—the intersections and connections of several structural elements. In the photo you see drawings of key connections.

How to connect elements of a sloping roof rafter system

The second option for connecting the side layered rafters and the upper triangle. Bolts are used for more secure fastening.

How to make a do-it-yourself fastening of the upper tee and rafter leg on an attic roof

Methods for attaching rafter legs to the mauerlat or, as in this case, to the side beam are shown in the figure below. To make it easier to mount a heavy element, a thrust board (bar) is nailed to the bottom of the rafter, which limits its movement: the board rests against the edge and does not allow it to sink lower.

Several options for attaching rafters to the Mauerlat

Selection of cross-section and sheathing thickness

The stage begins with choosing the type of sheathing: solid (selected for low slope slopes or low self-supporting abilities of the roofing) or loose (mounted on medium and steep slopes, optimal when working with rigid sheet materials). Next step by step:

• Based on the sum of the loads, the cross-section and thickness of the sheathing lumber is determined.
• The position of the first strip or the bottom edge of the sheet is determined.
• Taking into account the recommendations of roofing manufacturers, roof slope, rafter pitch and SNiP standards, the optimal sheathing pitch is selected.
• The need for strengthening of individual sections (if any) is clarified. Solid flooring or double boards are laid in the upper zone of slopes, under valleys, stairs or heavy objects.
• Manually or using programs, an approximate layout of the planks is calculated.
• A calculation of lumber and fasteners is carried out, the result is rounded up and the margin is increased by 5% (from 10% for a complex attic roof configuration).

Control type

Which roof window to choose - with automatic or manual control?

Automatic control - a new level of comfort. You can close or open the window using the remote control. You don't even have to get up from your seat. This is especially convenient if the windows are located high and difficult to reach.

Another advantage of automatically controlled windows is built-in rain and snow sensors. The attic will not be flooded by sudden rain - the system will close the windows itself at the right time.

Manual control is a standard and more cost-effective solution. In this case, you will close and open the windows using handles or telescopic rods.

Accessories

To make your windows more functional, use accessories. You will need:

• blinds, awnings, roller shutters. They will protect you from the sun. A roof window lets in about 40% more light than a standard façade window, so the lighting level must be adjusted. Also, these accessories will become part of the attic interior;
• telescopic rods. With their help you can easily reach high windows;
• Mosquito nets. They will protect you from annoying insects.

Services for calculating the required parameters

To simplify and verify the calculation, it is recommended to use:

• Professional programs such as Archikad, 3D Max, KZ-Cottage or ArCon (the latter is suitable for people without experience or construction education).
• Google SketchUp, Home Plan Pro, VisiCon and their analogues.
• Construction calculators and online services (stroy-calc.ru, stroysvoimirukami.ru, zhitov.ru, zamer-doma.ru).

Professional programs and applications allow you to create projects in 3-D projection and evaluate the expected appearance of the attic. The time spent on them always pays off - ordinary drawings do not give a full idea of ​​​​the bulkiness and influence of the attic roof on the design of the house.

Construction calculators require accurate initial data and are most often used when designing power structures and pie, choosing the optimal option and calculating materials.

Video tutorial on how to design a mansard roof in Archicad 16: