A number of interior styles, including those related to minimalism, allow or even welcome open elements of rafter systems into the attic space. These elements make the ceiling architecture more interesting and decorate the interior.

If the owners decide to leave the rafters and beams open, then at the design stage they must decide how much these elements should protrude towards the room. The fact is that their cross-section, which the designer must indicate in the project, will depend on this.

The cross-sectional dimensions of the rafters cannot be arbitrary. On the one hand we are talking about bearing capacity elements, and on the other hand, about the possibility of laying thermal insulation of sufficient thickness between them. If desired, of course, you can increase the rafters with inside, but this approach is, in principle, not the most rational.

The attic roof is a standard building envelope. Building regulations for such a structure impose corresponding requirements for resistance to heat transfer - R of the attic roof must be at least 4.95 m² C/W. In this regard, the layer of thermal insulation in the structure of the roofing pie must be at least 20-22 cm. This is slightly greater than the cross-sectional height of conventional rafters, which is 18-20 cm. The missing part of the thermal insulation is either not provided at all, or is laid between the slats frames that are installed for fastening plasterboard sheathing. Both solutions from the point of view of engineering and economic feasibility, as already mentioned, are not rational. It is necessary to look for other solutions.

Wooden rafters

The disadvantage of solid wood rafters, which are intended to be left visible as decoration on the attic ceiling, is that they do not have sufficient cross-sectional height. Standard wooden rafters allow only a few centimeters to be visible, since the maximum sectional height of finished lumber is limited to 24 cm. Thicker rafters must be specially ordered, which will sharply increase their cost.

If the owners are satisfied with the slightly protruding part of the rafters, then they can choose maximum size solid wood products. Most often, rafters are made of pine or spruce. When used in the interior, such materials are planed on four sides and also sanded. Sanded wood has higher fire resistance. The absence of roughness and notches does not allow the flame to easily “catch.” Wood treated in this way is also less susceptible to insect damage, because it is more difficult for the latter to penetrate through smoothly polished surfaces.

For exposed ceiling beams, green impregnated lumber should not be used. Impregnation penetrates deeply into the wood and planing cannot correct this. It is unlikely that green beams will suit their appearance; therefore, it is better to buy wood of a natural color, treated with colorless bioprotective preparations.

Laminated timber rafters

Glued laminated wood is made from individual lamellas of small cross-section, due to which products made from it can have a large cross-section and unlimited length. Today, glued beams with a cross-sectional height of up to 60 mm are available. However, laminated wood is much more expensive than solid wood. Every additional centimeter of cross-section is reflected in its price.

The lamellas from which the beams are glued can have a thickness from 18 to 45 mm. They are firmly bonded to each other with melamine resin or resorcinol glue. White glue lines indicate the use of melamine resin, and if dark, then resorcinol glue was used. The material of the slats is pine, spruce or larch wood. There are also imported glued products made from exotic species, which have high strength and durability.

The length of the lamellas is increased “by the mustache”, i.e. using a wedge connection. There are tinted and varnished products on sale.

For strength and other operational characteristics Glulam beams are superior to solid wood beams of the same section. In particular, in terms of strength, they are superior to products made from solid coniferous wood 2 times. The undoubted advantage of laminated wood is the unlimited length of the products, which allows you to design a rafter structure without support posts.

I-beam rafters

The I-beam has a cross-section in the form of two oppositely connected letters T. This type profile gives products rigidity in two directions, with a minimum cross-sectional area. Today, I-beams made of solid or laminated wood with an intermediate post made of OSB have become popular. Along with them there are beams made according to the same principle, but entirely from laminated wood.

The advantage of I-beams is their low weight. Such beams are easy to install. But in our case they are not very suitable, since their end part is small in height - 38-48 mm. Accordingly, it is precisely this visible protrusion of the beam that can be counted on, and no more. In addition, I-beams in the rafter structure, due to their load-bearing parameters, are installed in smaller increments than usual - namely, every 50-70 cm.

I-beams for floors have a wider beam at the end (89 mm). This makes them more visible on the ceiling. Due to this, when choosing an I-beam option, such beams are more in demand.

Thermally insulated footrails

You can get a large projection of rafters into the attic space by placing thermal insulation not directly between them, but on top of them. This task can be overcome only with the help of rigid slab insulation with low water absorption, for example, such as extruded polystyrene foam or foam glass. Laying thermal insulation on top of the rafters also significantly increases the resistance of the attic roof structure by creating a continuous thermal insulation layer where the rafters are not cold bridges. In this case, a continuous hard flooring is built on top of the rafters, which is covered with a layer of roofing felt or roofing film.

Insulation boards are laid on top of the flooring prepared in the described manner. They are attached to the rafters using counter slats and long nails that pierce the insulation right through. It is important to carry out the fastening in such a way that the counter battens cannot move down under the weight of the roof. To do this, you can drive the nails at an angle of about 67° relative to the slope; or screw the eaves overhang beam to the rafters, thus insuring the counter-battens.

For insulation over rafters, it is advisable to use slabs with profiled edges, which make the joints tighter.

Imitation of rafters

There are several ways to simulate open rafters, while the real elements of the rafter structure remain completely hidden in the structure of the roofing pie. Imitation can be achieved in several ways. The first involves nailing bars of the required cross-section to the rafters, possibly even exceeding the width of the actual beam. The protruding part can be made of more expensive and noble wood. This solution is primarily suitable for roof structures made of I-beam rafters. The false beams are glued to the rafters, since it is impossible to fasten them with through fasteners - the heads of the screws will be visible. Disguising these caps is quite problematic. If you cover them with wood putty and cover them with stain on top, the attachment points will most likely darken. The rhythmicity and symmetry of such dark dots will in no way make the imitation truthful.

In the second case, polyurethane imitation beams are used, which look almost identical to natural ones. Their only drawback is their high price. Otherwise, polyurethane beams in the form of boxes are very convenient interior solution attic ceiling slopes. These boxes are quite lightweight. They can be attached directly to the attic cladding using pre-nailed wooden blocks, or they can simply be glued. In the latter case, it is necessary to press the polyurethane beams tightly while the glue sets, for which you can use supports. When glued, wooden false beams sit on the tenon, so they do not need support.

Polyurethane imitations with different types finishing. Standard length polyurethane beams is 3 m and 4.5 m, and the cross-sectional dimensions are 120x60 or 160x100 m.

False beams can also be made in the form of U-shaped wooden boxes. However, their price can exceed false beams made of solid wood, so the advisability of hollow wooden boxes is due only to their relatively low weight.

A good foundation does not mean that the house will stand “faithfully” for many years. Another extremely important component is a reliable and high-quality roof rafter system. Let's figure out how it works in the case pitched roof, what types there are and what elements it consists of.

Roof rafter systems

What should be the rafters for roofs?

Here are several types of rafters that are most often used in modern construction:

• metal ones are difficult to change, but this material is durable;
• wooden ones are easy to use and change, but require additional processing;
• wooden I-beams (made from timber and OSB) are smooth with a maximum length of up to 12 meters, but the cost is higher conventional system made of wood;
• reinforced concrete cannot be changed at all, but they are distinguished by their long service life;
• mixed or combined systems.

Each of them has its own pros and cons, which include strength, price, ease of installation, the possibility of small changes associated, for example, with inappropriate dimensions, interaction with environment. This material will discuss the most popular material for making rafters - wood. Let us highlight the main tasks that are set for structures of this type.

First, and most importantly - strength each element. The roof should not deform or move. The basis of the rafter design is a triangle. It is in the form of a triangle that trusses (frames) are made, attached in parallel. Fixed and rigid, they “head” the entire structure.

Low weight. A heavy roof is extremely bad. Therefore, most elements are made from wood. If the weight of the roofing system is large, then it is reinforced metal frame. The base is coniferous wood with low moisture content.

What requirements the tree should respond:

• 1-3 varieties. No chips, knots or cracks.
• Wooden elements should not be less than 5 cm in thickness, and with an area of ​​up to 45 square meters. cm.
• The maximum length of coniferous timber timber should not exceed 5-6 m.
• Mauerlat and purlins are made exclusively from hard wood.

Main structural elements of rafters

Any owner planning the construction of a rafter system must be aware of what it consists of.

1. Mauerlat. The basis of the entire structure. Using this element, the correct load is set on everything load-bearing elements Houses.
2. Rafter leg. The slope of the slope is affected, gives the roof an attractive appearance, and reliably secures the structural parts of the system.
3. Puff. Does not allow the legs to “diverge”. Holds them firmly at the bottom.
4. Run. Attaches the rafter legs at the top of the system (ridge girder) and on the sides (side girder).
5. Lathing. Mounted strictly perpendicular to the beams. Made from cut timber or boards.
6. Posts/Struts. They “add” even more durability to the legs.
7. Overhang. Protects the main structures of the building from various natural precipitations.
8. Horse. The place where the ramps are fixed.
9. fillies. Create an overhang. Necessary when the rafters do not have the required length.

Details of rafter systems using the example of a gable roof, which can be used for various designs roofs

Let's look at such a component of the rafter system as a truss. It is made flat, and, in addition to stretching, it includes braces and the beams themselves. All these parts are fixed in such a way that the load on the main structures is vertical.

In the case where the span is quite large, the truss is made of several components. The bottom of the truss is the attic ceiling. The exact number of farms is determined after serious calculations at each specific site.

Types of rafter systems for different types of roofs

All design options are determined by two main types of rafter systems: hanging and layered.

Hanging

Ideal for gable roof types, with small spans - up to 5 m, without internal partitions. The lower support is the Mauerlat. In such a system, tightening is used, which reduces the thrust of the structure on the main supports of the building.

Hanging roof structure

The hanging rafter beams are located below - they also act as floor beams. In the case where the ceiling was made of reinforced concrete structures, they can also be system tightening.

Important additions:

• Don't use your legs as your main support element for roof overhang. More best option- filly (provided that the overhang is no more than 1 m wide). The leg, with this solution, transfers the load along its entire plane to the Mauerlat.
• When the wood has a moisture content of more than 20%, you should prepare in advance for the fact that after drying the system will begin to “walk.” The solution is to use bolts as fasteners, which can always be tightened. But, an even more “advanced” option is “powerful” mounting screws.
• Must be secured to the top of the roof wind board(should go from the Mauerlat itself to the top of the ridge). The corner is organized from the attic. This is needed to create the maximum strong roof, resistant to wind loads.

Layered

They are used for roofs with spans of 9-15 m. At the top, such rafters are attached to a ridge girder, at the bottom - to a mauerlat.

Layered rafter system

If the span is more than 15 m, then instead of a ridge girder, two side girders are installed, which are additionally attached to the posts. In the case where an attic will be created, a wall is used as a support for the layered beams.

Peculiarities:

• Any structural part of such a system should not be thicker than 5 cm.
• The surfaces of the elements must be as smooth and processed as possible.
• You need to be very careful when calculating the loads on each structural element.
• The Mauerlat must be positioned strictly horizontally relative to the vertical supports.
• Symmetry must also be adhered to when installing struts with racks.
• High-quality ventilation is the key to ensuring that your rafter system does not rot in the future.
• At the points where elements connect to stone or brick, good waterproofing is needed.

Depending on the roof shape chosen by the developer, its frame will also be different. We suggest you study various options for the most popular upper structures Houses.

Shed roofs

Manufactured at an angle of 13-25 degrees, such roofs have the simplest (in terms of manufacturing and installation) rafters. In the case of a small building with spans up to 5 m, a layered system is used. In cases where spans are more than 5 m, trusses are additionally used.

Gable

Also a pretty simple option. Especially when an attic or attic floor. Tilt angles - 15-63 degrees. If the main partitions are located at a distance of up to 6 m (relative to each other) - install hanging rafters. For running house sizes of 6x6 or 9x9 meters, we recommend using the following roof design diagrams.

Recommended installation diagram for a hanging truss system for a gable roof

When increasing the size of the house, it is necessary to modify (strengthen) the structure. In such cases, it is necessary to use layered technology.

Options for a gable roof for spans of more than 10 meters: the use of a layered rafter system

Hip or hipped

Rules for the construction of a hip roof rafter system

With tilt angles of 20-60 degrees, and spans of no more than 13 m. A prerequisite is internal reinforcing elements. For roofs of this type, trusses are used, or rafters are installed for layered roofs.

broken roof

Installation of sloping roof rafters

In its lower part it can have a slope of up to 60 degrees, in its upper part it can be flat. Due to this feature, the attic area becomes somewhat larger. The same types of rafters are used as in the version with hipped roofs. But it is recommended to use trusses.

Additional items

To create the strongest possible roof, each component The structure must be very firmly connected to the frame and other elements. In this case, it is extremely important to take into account the strength of the wind and the direction of possible mechanical loads.

Moreover, you should also pay attention to the wood. It may crack due to drying out. Therefore, it is important to create a design in which each element will “work” as harmoniously as possible.

Previously, all structural elements of rafters were secured with notches. But it was not a very “cheap and economical pleasure”, since it is necessary to take wooden elements large section.

Methods of attaching rafters to the mauerlat and ridge girder

So, today, not notches are used for fastening, but special bolts and dowels:

Metal linings with anti-corrosion coating are another fastener option. They are mounted on system elements using serrated plates or nails. The advantages of such fastenings are as follows:

1. Low consumption per unit of wood.
2. Easy to install.
3. High fastening speed.

Perforated fastening elements: corners, plates, beam support

Features of installation of the rafter system and mauerlats of gable roofs

Installation diagram of the rafter system in the case of a gable roof

I - mauerlat, II - rafter leg, III - ceiling.

Using narrow rafter legs is a “direct path” to sagging of the system in the future. To prevent this, you need to use a special grid - reinforcement, which includes struts, racks and crossbars. To create it, you need to take wood 2.2 cm thick and 15 cm wide, or use wood plates with a minimum diameter of 13 cm.

Roof rafters are the supporting structure of the slopes. It consists of elements that can be connected to each other by crossbars, spacers, racks, etc. The material for the support beams, in addition to the most common one - wood, can be anything - metal, reinforced concrete or mixed.

Table for calculating the rafter system depending on the distance between each other and the length

The wood (timber) must have a cross-section from 40 by 150 to 100 by 250 mm. This figure depends on the distance of the legs from one another, and the number of sediment loads for a particular area (calculation is carried out separately).

The board should not have more than 5 cm in cross section. Width is directly proportional to length. For example, if your board is 5 m in length, then its width should not be less than 13 cm. The main material of the roof sheathing is also important. When choosing it, you should pay attention to the presence of knots, chips and cracks. If you can’t find the most even pieces of wood, then maximum length knots should not be more than 1/3 of the thickness of the wood.

The last step in installing roof rafters is to securely fasten each element. Staples and metal corners are the most optimal elements for these purposes. But, in modern construction, bolts are increasingly being used.

Sometimes ceilings become the central elements of design, but besides this, in any case they also carry a practical load.

The rafter system is the supporting structure of a pitched roof. It consists of rafter legs, which are placed at an angle, as well as vertical racks. Absolutely any materials are used: wood, metal, concrete and others.

This photo clearly illustrates how each pair of beams connects to the horizontal beam. The load is distributed evenly, and the resulting structure is very reliable.

Design by renowned company Searl Lamaster Howe Architects, Chicago, Illinois, USA

Exposed ceiling beams are an excellent interior solution. It is this design of the ceiling in a house with a pitched roof, shown in the photograph, that makes the image more harmonious and complete. Don’t forget about this simple, very accessible, but no less spectacular design technique.

Gorgeous living room, designed by Anat Shmariahu, Cupertino, California, USA

The following photo gives us an idea of ​​how original a veranda ceiling can be. Here the beams are placed perpendicular to each other, and this is a very unusual architectural solution. This increases the height of the ceiling, creating something like a coffered structure.

Stunning porch with decorative ceiling beams, designed by the Frederick + Frederick design team, Beaufort, South Carolina, USA

The rafters extend beyond the outer wall to form eaves for water drainage. This is very original solution problems draining water from the roof.

Chic example of a home design with beamed eaves, John Lum Architecture, San Francisco, California, USA

The ends of the roof beams, which in this case are painted white, are called rafter tails. The blue rafters at the ends of the gables are outriggers.

Very unusual and stylish design rafters, designed by RW Anderson Homes, Seattle, Washington, USA

Also presented here original way roof design with protruding beams. They have no practical significance, but are simply elements of exterior decor.

Extraordinarily cozy summer house with decorative rafter beams, project SRM Architecture and Interiors, Portland, Oregon, USA

Exposed ceiling beams give the room the inexpressible charm of a rural house, while simultaneously fulfilling its main function - maintaining the roof. In our hectic times, country style is becoming very popular. His images put you in a romantic mood and have a calming effect. And the ceiling plays an important role here.

The textured and reliable design of the ceiling beams gives a feeling of unity with nature, design by Nurit Geffen-Batim Studio, Ra'anana, Israel

Arranged this way decorative beams create the illusion of a conical ceiling. You immediately feel a feeling of flight and lightness.

This design evokes images of places of worship, the vision of the design team at Aarcon Construction and Remodeling, Tomball, Texas, USA.

Rafters come in different levels, depending on the design of the house. The main thing here is to take care of the quality of the material and fasteners: the structure must be stable.

A home that delights in its simplicity, designed by Gaulhofer Windows, Duncan, Canada

Using ceiling beams, you can adjust the geometry and volume of rooms. If installed along the width of the ceiling, the room will visually expand. And in order to lengthen the room, the elements of the ceiling structure are laid perpendicular to each other. If the ceilings are too high, you can place the beams low under roofing covering. This will immediately add coziness to the design.

Ceiling beams will be appropriate in any interior, so don’t be afraid to experiment! Decorative wooden rafters will bring a feeling of warmth to the room, and metal constructions will create an atmosphere industrial loft. In any case, a room with an open ceiling structure will look unique.

Building small house, garage or outbuilding, it is not necessary to hire professional builders. Most of the work can be done on your own. Even if we are talking about something like this complex design, like a rafter system. Even some of the materials, or rather elements, can be made with your own hands. For example, rafters. This element is the main one in the roof structure. How can you make rafters with your own hands? What nuances exist and how to avoid mistakes? This will be discussed below.

Which material to choose

Making rafters for a house with your own hands is a completely doable task. But before you start, you need to select suitable material. The entire course of further work will depend on this.

What types of rafter materials are used? The following can be used for this:

1. Reinforced concrete products. This option is used in the construction of large industrial facilities. It is impossible to make such rafters yourself. And their use in the construction of private houses is not practiced.
   
2. Iron. Metal rafters It is quite possible to do it yourself. But they have many disadvantages. Firstly, metal is afraid of corrosion. Secondly, such rafters will weigh a lot. And this makes it difficult to do the installation yourself without the involvement of equipment.
   
3. Wood. It is this material that is most often used in the construction of the rafter system of a private house. Wood is easy to process. Therefore, making rafters with your own hands will be quite easy.

It is wood that is used for construction. But this material also has several options. Wood can be found in the form of logs, beams and boards. What is better to use for rafters? Much will depend on the design itself. Or rather, on the size and required strength.

Logs, due to their heaviness and bulkiness, are rarely used for rafters. The only exceptions can be pitched roof. And then in this case, thin logs from young trees are used for rafters.


Bars and boards are a completely different matter. They are used to make rafters for the roof. The beams are used in cases where the structure is large in size. At the same time, loads from precipitation and weight roofing material big enough. Boards are used for rafters in cases where the roof is small in size. Moreover, they can be used singly or in pairs.


Wood selection

Making rafters is a responsible business. The strength of the entire roof structure will depend on it, so you need to pay attention to all the little details. Before you start making rafters, you should stock up on material. As mentioned above, wood is best suited for this.

Which breed is better to choose? What kind of wood can be used to make strong and durable rafters? To work you can use the following:

• Pine. This option is most often used when constructing a roof truss system. Pine has many benefits. Firstly, such wood is impregnated with resin. This allows you to protect it from external influences. Secondly, the material is soft, and it will be easier to make rafters out of it with your own hands. Another plus is that pine is inexpensive wood. This means that you can save money;
• Spruce is another common material for making roof rafters. This wood is strong, light and easy to work with. But spruce has a slight drawback. It is more susceptible to external influences than pine;
• You can use oak to make rafters. The material is durable and well processed. But oak is very expensive. It is better to use it for.

The rafters can be made from other materials. For example, you can use beech. This wood is strong and durable, but it is expensive and difficult to process. If you choose aspen, you should remember some of its disadvantages. The most important thing is that this wood often rots from the inside.

The best option, according to most professionals, is pine. The wood is fairly common and will be easy to purchase. But the most important thing is its durability and ease of processing. You can easily make rafters and other roof structural elements from pine yourself.

There is one more modern version. Glued laminated timber can be used to make rafters. This material has several advantages. Firstly, it is not deformable. Secondly, it has standard sizes, which greatly facilitates the adjustment of rafters. But laminated timber is rarely used. This material is new, and it is not cheap.

It is very important to consider the quality of the wood you purchase. Of course, everyone knows that you should not purchase beams or boards with signs of rotting. But, in addition, you should pay attention to the moisture content of the wood. This parameter should not exceed 10-15 percent. Otherwise, the rafters will warp and the roof will soon require repairs.

What sizes to choose

If wood is selected, then before purchasing you should understand several more parameters. To make rafters correctly, you need to decide on their cross-section and length. Both parameters are determined by calculations.

Having found out what load the rafters must withstand, you can calculate their cross-section. There are many tables on the Internet. They indicate load-bearing capabilities rafters, depending on the material used in the manufacture, length and cross-section. With their help, you can easily select the desired parameter. The only thing that still needs to be taken into account when calculating is. The closer they are to each other, the smaller the cross-section can be used.

How to make rafters for the roof? In principle, there is nothing complicated here. Having found out what the length of timber or boards should be the required section sawed off according to the required markings. Next, a cut is made for and in the ridge area, and if another connection method is used, then this is not necessary. But to do everything right, you should take some advice from experts. Namely: