Features roof system in wooden and stone houses

It is said that the roof of the house - this is the fifth facade. Any owner of a country cottage is well aware that how well-matched roofing depends on the overall perception of the house.

We have already talked about the users of our website features the choice of roofing.

But the roof - this is only the visible part of a complex system called the roof. The foundation of any roof is reliable and properly designed truss system.

We cover the basic nuances of the erection truss system of wooden and stone houses.

General principles for selection of roof systems for the stone and wooden house

Often, novice developers believe that the choice of the construction of roof system can be left "for later" when there will be erected wall. Practice shows that it is fundamentally wrong. The roof of the house - is a complex system composed of many elements. Construction of the roof system should start at the stage of designing the house.

Vera Vavilova (the managing company "DDM Story"):

- Rafter system - is the foundation of (the skeleton) roof. Matter how well it is done, directly depends on the quality and durability of the roof. Production of roof system, particularly difficult, must begin with its design. This is the only path that will take into account all the nuances and accurately mount truss system.

instagram viewer

On how skillfully chosen and assembled truss system, the life of the roof depends on many things. It is also necessary to strike a balance between functionality and design delights.

Pavel Orlov (head of the company "Smart Story"):

- Design roof system starts with selecting the type of roof - Roof or cold attic. Typically, roofs for roof trusses angle of inclination is between 35 degrees and above. For cold loft angle base value trusses is 25 degrees.

The simpler the shape of the roof, the easier truss design, the faster it is to manufacture, and the builders less likely to make a mistake. Therefore, easier and cheaper to build operate the roof, having a simple form. A large area of ​​the roof, the presence of bay windows, a complex polygonal shape of the building considerably complicate and increase the cost of construction of roof system. This truss system requires competent planning and calculation.

The most economically advantageous truss system - from simple gable roof with a slope of not less than 25 - 30 degrees.

The main factors that affect the complexity of manufacturing and final price of the roof system:

• Type of finishing the roofing. The choice of the coating determines the composition of a roofing pie type lath and the load on the truss system. The most popular roofing - it's metal, soft roof, CHR (cement-sand tiles), ceramic or seam roofing.

• The angle of inclination of the roof. It defines the load, and it is a major factor in the design of roof system.

• Whether visible elements roof system (truss system as decorative element), or it is completely hidden behind a headliner.

• Large overhangs at the roof significantly increase the cost of roof system.
• If the construction of the last floor of the house has large unsupported spans, this entails a rise in the cost and complexity of truss system. In this case, depending on the distance, truss system is performed by farms.

• The presence in the project of large chimneys, skylights and other migratory cells significantly affects both the complexity of the manufacture of roof system and on its cost.

Roof system design (particularly difficult) should deal with a person who has the relevant experience. Truss system is calculated for a specific house. A common approach - 'do stropilku as a neighbor, "often leads to disastrous results. Truss system does not withstand load, which ultimately leads to costly rework.

These loads include:

1. Constants, including cumulative weight roofing insulation material and fastener elements.

2. Temporary value. This load, which have a roof on the climatic conditions, especially snow and wind.

Typically, designers lay a settlement step rafters in accordance with the intended load. Is this true?

Pavel Orlov:

- In my opinion, a step for roof rafters, well insulated roofing is best to choose, based on the amount of insulation - so that the distance between the rafters turned out to 1 cm less than the width of insulation. This will simplify its installation.

The main load, over which the calculation of roof system - snow. Usually all truss structure designed with a reserve, but if in doubt (for example, to mount the heavy roof covering - natural tile), you can slightly reduce the step rafters.

Although the snow load is intermittent, the truss system should be calculated taking into account the totality of the loads acting on it. Calculation of roof system is necessary to conduct not a "butt", but with some reserve, for example, in the event of heavy rainfall (prolonged snowfall) or high wind load.

In addition, the "job" roof system is significantly affected by the choice of material for the walls of the house.

Features roof system in a wooden and stone house

The main difference between the rafter system a stone house from the wood - that the stone walls are not subject to shrinkage and deformation.

Pavel Orlov:

- Rafters stone house do not require deformation elements as stone house practically does not shrink. The main feature of truss system of the stone house - is the need to secure reliable mauerlat. The wooden houses mauerlat role performs the wall.

Mauerlat - a roof element (paired board 50h150, 100x150 or 150x150 size bar), which is placed around the upper perimeter of the house wall. On mauerlat based lower part of the rafters. Thus mauerlat redistributes point load transmitted from the trusses to the whole area of ​​the top of the wall.

Also in the design of roof system stone house is necessary to consider the thickness of the walls.

Pavel Orlov:

- Any design of roof system requires the calculation of allowable lateral load on the trusses wall with fixed mauerlat.

The thin wall and high withstand a smaller lateral load. This requires the use of load-bearing structure trusses additional elements - retaining struts and girders.

In wooden houses there are also some nuances that need to be taken into account in the manufacture of roof system.

Vera Vavilova:

- The main feature of the truss system of the wooden house - that the walls, which are the basis for trusses, shrink and change their geometry when changing weather, temperature and humidity inside and outside houses.

The main element that compensates for the shrinkage of the walls with respect to the rafters - a sliding support (it is also called skolzyachka). The sliding bearing is needed in order to compensate for distortions truss construction resulting from shrinkage of natural wood humidity.

Shrinkage house rafter slides along the rail, thus compensated for all the distortions of the general construction of roof system at home. Moving part of the support it is attached to the rafters so that between it and the rafters there is a gap. A corner with rail is screwed to the beam.

Skolzyachka must be set strictly perpendicular to the rafters, with gashes in the rod for its installation base. To shrinkage of wooden structures to provide maximum stroke skolzyachki at its installation it is set in the most extreme position.

The degree of shrinkage of the wooden house (and hence the value of progress, acting on the rafters) depends on the material used in the construction of walls. For example, timber natural humidity gives greater shrinkage, dry profiled shrinks less, and glulam gives minimal shrinkage.

Housing walls folded from a dry timber may shrink to 6% of their total height. When it comes to the walls of the house, built of timber of natural humidity, the shrinkage can be more. On what the pros and cons have dry profiled timber and conventional, explains in detail in this article.

In addition to timber, wooden houses erected in the so-called hand-cutting of the log. Practice shows that the truss system of the house has its own characteristics.

Dmitry Filippov (specialist company "Traditional carpentry technology"):

- The log houses based on the log used Samtsova slegovaya-roof system device plus "sliding" part of the truss.

The peculiarity of this design that came down - horizontal logs, log in vrublennye pediment (top of them - it's Pipit) - sit down together with the framework. Next came down to fit knocked out of the board (aka ceiling). Mounted on the rafters (a saddle roof are mounted on the ridge to each other sliding mountings). Then, a roofing pie - vapor barrier, insulation, waterproofing, kontrobreshotka, sheathing, roofing material is laid on top.

Dmitry Filippov:

- Thus, the part of the truss with roofing pie is not tied to the frame, as it were, "lie" on it, which allows the roof shrinkage log to keep its shape and integrity.

About the features of the material of choice for the construction of wooden houses gives details in this article .

Materials, reaching the rafters

In addition to accounting features wooden and stone houses, in the construction of roof system is necessary to understand the requirements for lumber.

Vera Vavilova:

- For the manufacture of roof system houses suitable pine and spruce. It is cheap and meet the basic strength characteristics of wood trusses.

It is important to track and make sure that the timber truss system posted 0-2 grade according to GOST 8486. rafter elements should not contain large loose knots, rot, cracks and wane. These defects weaken the carrying capacity of truss system.

Pavel Orlov:

- At the truss system is usually employed edged softwood species humidity up to 20%. All used timber to be processed by certified ognebiozaschitnymi impregnation.

If you put on freshly sawn rafters, wet wood, the drying process is already mounted rafters will lead. This will cause deformation of the roof and roofing.

To avoid this, elements of roof system is best done from a calibrated timber drying chamber.

Another option of the materials used for the manufacture of roof system can be a farm, and laminated beams.

The use of these materials is determined by the project based on the magnitude and spans the expected load on the truss system design.

Vera Vavilova:

- In this case, the elements truss system manufactured in a factory and brought to the site in the form of parts, ready for assembly.

This eliminates the so-called "human factor". Also saves time because this truss system is going faster than the one made in the area with the inevitable sawing and fitting the pieces in place.

Factory truss system are made strictly according to the design and specifications. Due to this, a high quality of future base of the roof, since wood already processed antiseptic agents, and the entire truss system is going on the principle designer.

Another material used in the construction of roof systems, stone or wooden house can be a light steel thin-walled structures (LSTC). This truss system does not need to handle antiseptic means, it has a light weight, long life and high fire resistance. Consider the main features of the truss system, erected on the technology.

Andrey Usachev(Deputy Commercial Director"Polymetal-M"):

- The roof truss system made by LSTC technology include galvanized rack and guide profiles. If necessary, warm roofing thermoprofile is used (with perforation profile across the length), which will remove the cold bridge and avoid heat loss.

Each element of the system has a strictly predetermined size of the project.

This significantly reduces assembly time truss system, and avoids waste on site.

Each profile is marked in accordance with the drawings and the assembly manual.

Andrey Usachev:

– Thanks to the labeling, simplified assembly of truss system. In addition, each profile applied puklovka (pads). Because metal frame fastened together with screws, thanks pads clear where must be the connection. In addition, puklovka increases the rigidity of the assembled unit, reducing the force acting on the slice on the screw.

How to start the construction of the roof? The answer users FORUMHOUSE can learn in this topic. Here gathered all of the truss system information. To learn how to build roof trusses with their hands, tells here.

A detailed photo report on the recast of the rafter system is represented by the wooden house here. Can the incorrect installation of roof system to break up the stone walls at home? find the answer here.

The roof in the Russian wooden architecture, what is it? It is shown in this video.

Discuss the article and read other materials devoted to country life you can on the websiteFORUMHOUSE.

Subscribe to the channel so as not to miss the next release!