Roof in a log house. Under the roof of my house, construction is in full swing, choosing natural tiles for the roof of a log house. What kind of roof should be installed on a log house?
In Russia, the construction of residential buildings made of wood is based on many years of experience and ancient traditions. It was no coincidence that our ancestors chose this reliable material. Wood is still valued for little weight, ease of processing, low thermal conductivity and a healthy, healing microclimate that forms within the walls wooden house. Many people who rebuild timber and log country houses, country houses and even city houses are wondering which roofing is best suited for structures made from this material. In this article we will talk about the most successful designs roofs and roofing materials suitable for wooden construction.
The roof is an integral part of the structure of a wooden house, the quality of which determines the service life of the structure, the safety of the people living in it, as well as temperature regime in the cold and warm time of the year. The roof is considered one of the most difficult parts to construct, since it consists of many elements and its structure resembles a layer cake. A wooden house is characterized by two types of roofing:
- Cold. A roof is called cold if its structure does not include thermal insulation material. Russian towers traditionally had this design. Attic cold roof was not used constantly, so it was not the slopes that were insulated, but the floors using backfill thermal insulation material, most often sawdust.
- Warm. Warm roofing is a roof erected over residential attics or simply heated rooms. In this case, the composition of the roofing cake must include insulation and vapor barrier. Construction of a warm roof is more expensive, but it helps to significantly increase the area of the house by using the under-roof space.
Important! Modern wooden houses can be built with cold and warm roof depending on the project and the needs of the developer. Experienced craftsmen believe that for structures with an unheated second floor or those used seasonally, it is better to choose a lighter and less expensive cold roof, which forms a natural air cushion that protects against overheating and hypothermia.
Varieties of forms
The shape of the roof of a wooden house can be varied. The choice of the type and number of roof slopes depends on the design of the structure, climatic factors, the nature of the use of the under-roof space and the taste preferences of the developer.
The most suitable forms for roofing wooden houses are: Note! When deciding which roof to choose for a wooden house, carefully consider the angle of the slopes. The choice of this indicator is based on climatic conditions , characteristic of the construction region. For areas with big amount precipitation in winter period
Designs with a slope of 40-45 degrees are suitable, from the slopes of which snow easily rolls off. For windy areas, flat roofs are better suited, the angle of slope of which does not exceed 20-25 degrees.
Roofing material The construction market offers a huge selection of roofing materials suitable for covering the roof of a wooden house. They are highly weather resistant, durable, long term service and aesthetic appearance. The roof of wooden structures should not prevent them from “breathing”, creating a greenhouse effect, therefore
experienced craftsmen It is recommended to choose among the following coatings: Please note that it is better to use lightweight, durable and non-flammable materials, which do not weigh down the structure of the house. If you choose according to these criteria, then metal tiles and
seam roofing
- made of galvanized steel.
- The construction of roofs for houses made of wood differs from the construction of roofs for structures made of other materials. An inexperienced craftsman may make some mistakes, which can lead to deformation or even collapse of the structure. To avoid problems when operating your home, the following factors must be taken into account:
- Shrinkage time. Please note that timber and wooden houses shrink during the first time after construction, significantly changing in size. Therefore, the roof for them is erected only after a year of construction.
Use of movable fasteners. When humidity changes, wood changes in volume, which is why wooden houses are said to breathe. In addition, they shrink even five years after construction. Therefore, when constructing a rafter system, it is recommended to use movable and sliding fasteners. Fire hazard. Wood is a highly flammable material, so it is recommended to treat the elements of the rafter frame with fire-retarding substances. It is better if the roofing covering for such houses is non-flammable, for example, metal tiles. Important! For roof insulation environmentally friendly materials, and creating a “greenhouse effect” inside, which leads to dampness or rotting of the wood.
A wooden frame made of timber or logs is a traditional building for Russia, which is used for both housing and utility premises. The process of assembling such a building takes place according to long-known and constantly improving technologies, so the house turns out to be cozy, warm and comfortable to live in. The design of the rafter frame deserves special attention, because many qualities of the roof and the functioning features of a gable roof depend on its strength and reliability. It is important to know how to install rafters on a log house so that they can withstand all the necessary loads and serve correctly for many years.
A rafter system is usually called a roof frame, a unique set of supporting elements that give it shape, slope and sufficient bearing capacity. Such a roof foundation is made of dry and durable wood, treated with antiseptic preparations, or a metal profile. This frame evenly distributes all the loads falling on it between the load-bearing walls. Used on log houses the following types rafters:
- Hanging. Such rafters have only one support point - the mauerlat; they rest against each other with the free end of the rafter leg, forming a kind of triangular arch. This design for a gable roof is used when the log house inside does not have load-bearing walls on which it would be possible to install racks. This rafter system experiences sufficient strain on expansion, which is why it turns on various kinds
- puffs designed to compensate for such tension. Hanging rafters are distinguished by their massiveness and some complexity of installation. Layered. This type of rafters has two points of support - the same Mauerlat and the ridge girder that supports vertical racks. This design is used provided that there is at least one
load-bearing wall or a series of columns onto which the ridge can be unloaded. Layered rafters experience load only in deflection, so they are easier to install. The log house is made from a well-known natural building material - wood, which has
Important! The most significant changes in the size of the object occur in the first year, so it is recommended to secure the rafters only after this time.
Mounting methods
Attaching rafters to a wooden frame is a technologically quite complex process, from correct execution which directly affects the strength, durability and integrity of the roof. When working, it should be taken into account that wood tends to settle during the drying process, so the geometry of the entire building changes. In addition, this material is subject to thermal expansion, so there is no need to attach the rafters to the frame too tightly to avoid deformation. Rafter legs can be attached to the frame using two types of fastenings:
- Movable. Such rafter fastenings are called special metal fasteners that allow the structure to be given a certain degree of freedom in movement and change in size. With their help, the rafter legs do not receive a deflection load, and can also react to the slightest temperature fluctuations, adapting to the geometry of the log house. These products allow you to attach rafter frame
- until the end of the building's shrinkage without the risk of deformation.
Stationary.
Fixed type fasteners do not leave a margin of mobility when installing rafters, however, they largely guarantee the strength and rigidity of the structure. Such fastening elements include nails, wooden dowels, self-tapping screws, metal staples, overlays, and so on. Important! A log house made of wood has one extremely unique ability - it can, as people say, “breathe.” This means that the log house itself can regulate the humidity in the room, which is why its dimensions are not clearly fixed. Movable fasteners that can adapt to the shrinkage of walls and changes in the size of the material as a result of a reaction to thermal influences -
best option
fastening the rafters to the frame. Assembly methods After shrinkage wooden log house has finally passed, they are starting to establish the rafter system and erect the roof. This process complex and painstaking, especially if you work alone. There are 2 ways
- correct installation frame on the Mauerlat: Installation of ready-made roof trusses you need special equipment such as a crane, aerial platform, tractor, etc. This is how layered rafters are usually installed, weighing less than other structures.
- The assembly of trusses is “top notch”. Given the large weight and size of the rafter system structure, along with the lack of special equipment, the trusses are assembled directly on site. The disadvantage of this technology is the complexity and inconvenience of such work.
It is worth considering that experienced craftsmen rarely use the method of installing ready-made trusses, because these designs do not allow achieving high precision in fitting the elements, although they significantly save time.
The rafter system on a log house may be a fairly common option in Russia, but the issue of installing rafters must always be approached with full responsibility, because the reliability of the gable roof and the entire building as a whole depends on it.
The roof of a log house, like the roof of any wooden house, should be simple. The gable roof of a log house with an attic is reliable and easy to use. Attic insulation is easy to install, and special costs And expensive materials it doesn't require anything, and the effect is excellent. in winter attic roof The log house helps keep the house warm and cool in the summer.
Main elements of a log house roof
Main roof elements:
- A rafter system consisting of roof trusses. Trusses, in turn, consist of rafters (another name is a rafter leg) and racks. The rafter legs are connected using pieces of boards called crossbars. The crossbars and posts provide rigidity to the roof truss and distribute the loads from the weight of the roof, snow and wind. To create an overhang, the rafter legs are extended with pieces of boards called fillies.
- The ceiling of the log house is made of timber or logs, called matitsa. The mats are hemmed from below to form a ceiling, and the attic floor is laid on top. For insulation, an insulating layer is placed in the gaps of the mats.
- To prevent rain and snow from falling on the walls of the log house, they organize a roof overhang. The horizontal projection of the overhang is 750-800 mm.
- The ends of the attic are decorated with boards, forming gables. Canopies are placed under the gables to divert atmospheric water from the walls of the house. A residential attic can be arranged with an attic. An insulated attic is a very attractive option; it increases the living space of the house and gives the house charm, but we must remember that its renovation is quite complicated. To insulate an attic, you need to lay insulation between the roof rafters, along all slopes. During operation, it is not always easy to eliminate possible leaks, and the insulation takes a very long time to dry, and wet insulation does not fulfill its task. The appearance of frost on the ceilings of insulated attics in winter is not such a rare occurrence. It is worth remembering these difficulties when choosing insulation and the type of attic insulation.
- The roof can be made of almost any material that modern construction market offers in abundance. Slate, ondulin, ceramic tiles, metal tiles, cement-sand and bitumen tiles - they all have a lot of advantages and inevitable disadvantages. A soft roof, which is not afraid of wind and repairs, has additional unique advantages and a serious disadvantage - high cost.
The strength of the log house materials - logs and beams - allows the use of any type roofing covering.
Installation of a building system for a log roof
Features of installation of the log rafter system
- Mats serve as supports for the rafters. Their protrusions beyond the walls of the log house are aligned “along the cord”, and to bring the upper surfaces of the mats to the horizontal, their planes are either cut off or raised by nailing a board of the required thickness. The thickness of the leveling boards and the depth of trimming are also determined using a stretched cord.
- The assembly of the first roof truss requires special precision, because once adjusted, this truss will be used as a template for all subsequent trusses. The trusses are assembled using nails 100 mm long (weave).
- It is important to ensure installation density rafter legs into the recesses at the ends of the mats; for this, a tenon template is made at the end of the rafter leg and all the ends of the stops are cut along it. Tools for making recesses in mats - a hammer and a chisel. The recesses are selected according to the template of the rafter leg tenon, at equal distances from the ends in each matrix.
- After marking the recesses, the first, template truss is disassembled and the required number of elements for all trusses is prepared from its parts; fillies are also prepared in the right amount- two per farm. The fillies are prepared one meter long from boards 50*100 mm.
- The entire assembly of the trusses is done at the bottom, also using hundreds of nails. Particular attention is paid to controlling the distances along the rafter tenons. They must correspond to the distances between the lower points of the recesses of the matrices.
- The installation of roof trusses requires two workers, since the installation is done with vertical adjustments along the plumb line. Temporary rigidity is achieved by fixing it with boards - spacers.
- Attaching the rafter legs to the mats is done with 200 mm nails, with 6-8 mm drilling to prevent the wood of the ends of the rafter legs from splitting.
- When all the trusses are installed, the racks are installed. The posts are attached to the rafters at the top using double-sided pads. The verticality of the racks is verified with a plumb line, then the rack is inserted with a tenon into the recess of the matrix and adjusted in height by trimming it in place.
- To install the overhang, fillets are installed with an outlet beyond the rafters of about 300 mm, while the projection of the roof overhang onto the ground surface will be about 800 mm, but not less than 750 mm for the organization reliable protection walls of the house from rain and snow. Of course, the release of fillies can be of a different length, this depends on the design features of the rafter system used. But in any case, it is irrational to make the overhang less than 450 mm for a brick house and less than 600 mm for a wooden one.
- To install the fillies, notches are made at the ends of the mats, next to the rafter legs, using chisels and a hammer (mallet). Nails for nailing fillies are also used - weave, and the installation of fillies along the length is set “along a stretched cord”.
Installation of the under-roof structure of a log house roof
Traditionally, this structure consists of rough flooring, waterproofing and sheathing with counter-battens and must ensure reliable fastening of the roof, uniform distribution of the entire load from the roof on the rafter system, and also ventilation of the attic space.
- For the installation of rough flooring use edged board, plywood, chipboard and fibreboard, as an economical option is possible unedged board with underlay when laying. To create additional rigidity for the flooring, two or three nails are driven in at the joints of the flooring boards at the level of the rafters. The flooring serves as the basis for waterproofing and counter-battens, forms the overhangs of the gables, and for roofs with a small angle of inclination, the flooring acts as a sheathing. The lower flooring boards are cut and even, and the overlap of the gable overhangs is made more than 600 mm, for further trimming on site.
- Any rolled materials are suitable for waterproofing carpet. But if waterproofing is installed for an insulated attic, then the material must have both waterproof properties and vapor permeability. Laying roll material done from below, horizontally, overlapping technical specifications material, but not less than 150 mm.
- The counter-lattice is stuffed from bottom to top, on top of the waterproofing layer and consists of bars 25*60 - 30*70 mm. The pitch of the counter-lattice is from 30 to 60 cm and depends on the type of roofing; this information is given by the manufacturer in the material installation manuals.
- After installing the under-roof structure, the roof is installed.
Pediments and gable canopies complete the device. The gables of the log house can be made from different materials– asbestos-cement flat plate, metal tiles, plastic, plywood, it all depends on the construction budget and preferences.
In this article we will talk about the design features of the roof of houses built of wood, or rather log houses and timber houses. What they have in common is that they are subject to shrinkage after assembly.
Here all the pictures will show, simply because it is still difficult for me to draw log walls on the computer. But in general, everything that will be said applies equally to timber houses and to logs.
So that's it wooden buildings Depending on the construction features, house roofs can be divided into two types:
With frame gables;
With gables made of timber or logs.
I Option:
If the roof is made with frame gables, then in principle it is no different from roofs brick houses, which we discussed in previous articles.
Let's say we have a box at home, shown in Fig. 1:
Picture 1
We can build either a gable roof with layered rafters, with the latter resting on the floor beams (see Fig. 2):
Figure 2
Or on such a house we can make a roof with hanging rafters, with the latter also supported by floor beams, as shown in Fig. 3 or as described in detail
Figure 3
We see that there is no ridge beam resting on the middle load-bearing partition. The upper ends of the rafters rest on each other through the ridge board. The role of tie bars is performed by floor beams.
We can also use both of these schemes, only support the lower end of the rafters not on the floor beams, but on the mauerlat. Or rather, on the top crown of the box (log house), because V wooden houses it is he who is the Mauerlat. In this case, when using hanging rafters you will need to add tightening. Similar roofs were previously described in articles And .
So we have four schemes. On the sequence of construction of gable roofs and necessary calculations, I think we have already talked enough in previous articles. Which scheme to choose is up to you. From the point of view of reliability and simplicity of construction, I would prefer the very first option - layered rafters supported by floor beams (see Fig. 2), of course, provided that we have a middle load-bearing partition.
II Option:
Now let's talk about the features of the roof of houses with gables made of timber or logs. Their main feature is that the pediment is subject to shrinkage, i.e. Over time, its height changes (decreases), and the angle of inclination of the slopes changes accordingly (also decreases). What could this lead to? Let's look at Figure 4:
Figure 4
We took the same box at home and made gables from timber. A ridge beam was placed on them to install layered rafters. Of course, with such a length, it is obvious that the skate will not survive. Someone here might come up with the idea of putting vertical racks under it, resting them on the middle partition.
But let's just say this idea is very bad. The height of these racks will not change over time, because... shrinkage of wood along the grain is only 0.1-0.3%. The height of the gables can be reduced to 8-10%. Those. with a pediment height of 1.5 meters, it can sit 12-15 cm. Imagine what will happen to the roof.
In this regard, if we want to make gables from timber (logs), the middle partition must be assembled to the very top and settle together with the gables. Figure 5 shows, as an example, several houses where the ridge beam will lower evenly as the house shrinks:
Figure 5
On last photo we see that the ridge beam on the balcony is supported by a vertical post. But this stand is installed through a special screw compensator shrinkage of the log house.
Now a little about securing the lower ends of the rafters on houses with gables made of logs or timber.
If we imagine the process of shrinking the pediment and, accordingly, lowering the upper end of the rafter, it becomes obvious that the lower end of the rafter will shift relative to the wall, i.e. as if sliding down. But in this case, how to secure the rafter to ensure its mobility. The methods of attaching the rafters to the Mauerlat, which we considered earlier, are not suitable here. And the scheme with the rafters resting on the floor beams is not applicable at all in this case.
How this connection is made is shown in Figure 6:
Figure 6
A shallow cut is made on a beam or log (the saw blade is not filed) and a special sliding support. You need to keep an eye on two things. The “slider” should be perpendicular to the rafters, and during installation it should be cocked to its lowest position (as shown in the photo above) to ensure the maximum possible movement of the rafters when the pediment shrinks.
The connection of the rafters to each other at the top of the ridge also has its own characteristics. They should be able to slightly change the angle of inclination when shrinking. Two most simple ways how to ensure this is shown in Figure 7:
Figure 7
So, let's summarize. In roofs with gables made of logs or beams, the rafters should be able to move when shrinking and nothing should interfere with this. No tie rods or additional intermediate posts are placed on such rafters. The connections are also made movable.
The roof of a house made of rounded logs must be both durable and beautiful, withstand snow and wind loads and reliably protect the building from all the vagaries of nature. There are several roofing options that are suitable for a wooden house; they differ in the location of the rafters and the number of slopes.
What should the roof of a house made of rounded logs be like?
Main types of roofing systems
The roof of a house made of rounded logs is selected depending on the size of the building and the location of the premises.
There are several basic, most common options: Installing a roof in a rounded house can be done with your own hands, but if you don’t have experience, it’s better to opt for a simple one. gable system – that’s quite profitable solution
, which can be used for buildings of various sizes.
How to build a gable roof Installation of the roof of a house made of rounded logs begins with careful calculations. First of all, this concerns its slope: in areas with a drier climate, the roof slope can be 25-40 degrees, this is enough to withstand snow load
. If the climate is characterized by heavy snowfalls, then the slope should be a minimum of 40 degrees, and a maximum of 60. However, the wind load must also be taken into account, since as the slope increases, the windage also increases.
There are two options for arranging the rafter system: When the rafter system is assembled and installed, you can proceed to installing the sheathing and installation. The lathing depends on the chosen coating: for soft roof it is solid; for metal tiles or slate, horizontal bars 5 cm wide are sufficient. The spacing of the lathing depends on the type of material; for each of them, the manufacturer recommends its own dimensions.
If a house is being built for permanent residence, it is necessary to insulate it. In this case, a multi-layer “roofing pie” is created, which will protect the house from heat loss and protect the rafters from the destructive effects of moisture. Insulation is laid between the rafters, usually used for this mineral wool. From below it is covered with a vapor barrier layer: the insulation should not be destroyed by water vapor rising from living quarters.
On the upper side it is covered with waterproofing; for this, a counter-lattice is installed. Afterwards, you can begin installing the top roof covering. At correct assembly a roofing pie can last for decades. The roof of a wooden house must be in harmony in its external design with the building itself; this issue must be resolved during the development of the project.
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