Gambrel roof truss system: Design Features

Wooden house with a hipped gambrel roof

The lack of height makes gables house with a hipped roof visually smaller, but overall housing construction with a roof looks organic. Photo of single-storey houses with hipped roof indicate that often the space directly under the roof is used for arranging a cozy attic room. For the lighting of the attic in the roof of a full-window design.

Photos of houses with hipped roof trim illustrates the outlines of the roof, which are often equipped with skylights. This makes the roof of the colorful and interesting in design plan. Hipped roofs are usually used for large-area buildings, the base of which forms a rectangle. If the perimeter of the house has a square shape, then use a different kind of hip roof - hipped.

A single-storey house with a hipped roof

The main feature of the hipped roof is the fact that all its rays have the same shape of an isosceles triangle and an identical angle. Gathering all faces in this construction, one upper point. Hipped roof relevant also in homes that have the right shape of the polygon. How many sides in the polygon, and so symmetrical ramps will have a roof. From the viewpoint of architecture, such constructions are not less attractive.

Another subspecies of the gambrel roof - poluvalmovaya roof. This combination in one design gable and gambrel model. To give streamlined roof gable cover small triangular ramp (poluvalmoy), the slope of which length is shortened. Such an embodiment ensures that the roof ridge element becomes removed from the action of wind flows. When you use the space under the roof in the attic there is an opportunity to equip in the gable of the full window.

Related article:

Roof truss system poluvalmovaya: especially the construction and installation. Calculations and construction stages. Selection of insulation, the insulation layer and roofing material. installation and finishing algorithm poluvalmovaya roof.

Exceptionally look hipped roof with a bay window. Oriel roof are added throughout the house building romance and sophistication. It is possible to meet with the roof bay windows, and attached to the main structure or separately erected above the projection wall. The main drawback of such roofs is the complexity in the design and installation of rather expensive.

House with a semi-circular bay window

To cover the hip design can be used in almost all modern roofing materials: slate, decking, metal, ceramic and shingles and other materials. Roof covering is chosen considering the slope of the roof, features climate region, material characteristics. In addition, the important role played by the durability, aesthetics and cost of the coverage.

Note!Use as tent coating sheet roofing structure entails a fair amount of waste.

Getting acquainted with the construction of hipped roof, you may find that agree with each other all the slopes with the same slope is difficult. Requires accurate calculations, competent design and theoretical recommendations of professionals. But despite the complexity of the frame structure, hipped roof are the undoubted popularity among private developers.

Modern house with a hipped roof

The main advantages of hip roof

In addition to the original design hipped roof has a number of advantages, which favorably distinguish design from other models:

• no gable design promotes invulnerability to strong wind loads. The smaller the slope of the roof slopes, the minimal impact of wind exerts pressure on the truss system;
• streamlined shape all four ramps promotes stability of the structure to any type of precipitation;
• As regards the effectiveness of energy saving, such a design is superior in many respects gable roof;
• warm gambrel roof is much easier, as the insulating cake is under slopes. In models of roofs with gables - it requires special insulation vertical facade, more susceptible to the power of the wind;
• nakosnyh system, central and Narozhnyi trusses provides a reliable design, resistant to deformation by external forces;
• depending on the slope, there is a possibility of rational use of the space under the hip roof to the attic and construction of roof windows.

Along with the special appearance hipped roof has a high degree of reliability and durability

The main disadvantages are the complexity of the models hipped roof system gambrel roof and the inability to everything in the attic with a slight slope models. However, with proper study of the drawings hipped roof and an attention to detail measures for the construction, the construction of such structures become realistic goals.

Gambrel roof truss system: the basic elements

The frame is a hipped roof ridge beam and rafters different system. Taking into account the fact that the ramps and hips have a different slope, there are several types rafters. The main components of the design include:

• angle rafter (nakosnye) - main load-bearing structural elements, arranged on the frame corners. Nakosnye rafters have a smaller slope relative to the other between rafters;
• central rafters - they are attached to the ends of a ridge: on each side of the three elements. They are called intermediate central rafters;
• intermediate rafters - disposed between the central rafters, originate from and terminate on the strapping ridge;

Gambrel roof truss system

The photo frame of roof hip roof can be seen that the ridge pole is located exactly in the center and parallel to the bearing walls of the house. In addition, the beginning and end of the run must be the same distance from the end walls. Such an arrangement provides uniform load distribution, and, consequently, the stability of the construction.

Scheme hipped roof truss system

Hipped hipped roof surpass the complexity of the construction of the conventional gable model. This is due to the complexity of accurate docking all four ramps at the desired slant. Such roofs have two big ramp in the shape of a trapezoid and two end ramp to form a triangle. In forming the roof system, and there are major difficulties devices hipped roof.

House project from hipped roof recognizes that slope ramps should be between 10 to 60 degrees. The choice of the angle of inclination affects the amount of precipitation, the material roofing and then whether to use the roof space under the attic. In regions with high rainfall slope should be less than 45 degrees.

Scheme gambrel roof should be provided section of the shape, size and exact location of all the frame components. In addition, in the drawings of the roof truss system of the hip affects the length of the ridge pole, height roof inclination skates, the width of spans, construction and amplification methods specificity fastening elements.

Schematic design gambrel roof

Given that nakosnye rafters are long and are a reference for narozhnikov, they need to be strengthened. To do this, use Sprengel, the beam that hit the mauerlat and propped up the bar nakosnuyu leg. To strengthen the truss system practiced by the use of wind girders. Its fixed on the inner side of the central rafters diagonally predominantly windy side of the house.

In the case where trusses have a length of more than 4.5 m are used for their amplification diagonal struts, the use of which allows selection of a smaller cross-section beam trusses. Struts abut the tightening (joist), which do not allow to disperse the rafters. If tightening mounted closer to the ridge beams, they can serve as a foundation under the skin of the ceiling of the attic floor.

Useful advice!The closer the beam puffs attached to the ridge pole, the more powerful must be fixing roof system.

In Scheme hipped roof trusses expediency use naslonnyh or suspension trusses, as well as the use of additional reinforcing elements. If the calculations it appears that the beam parameters do not meet the required load can be applied or glued typesetting roof beams. These modified elements are significantly more massive and may have a greater length.

Truss system at home with gambrel roof

If housebuilding has an intermediate bearing wall, then use hanging rafters, which are based only on two pillars (on two walls of the house). In this case, rafters experiencing strain on the compressive and flexural strength. Since the rafters create arching force on the wall, use a wooden tightness, which connects the rafters. Usually it settles down at the bottom of rafters.

When the structure has an intermediate bearing wall supporting pillars or medium used diagram naslonnyh trusses. In this embodiment, one end rafters rest on the outer walls and for the middle of the foot support is a column or an inner bearing wall. With this structure, truss elements operate on a bend, like the beam.

Compared with roof where use Hanging rafters construction with naslonnymi rafter is easier. On the construction of a roof it uses less materials, thereby reducing construction costs. You can use a combination of roof system in one design. This occurs when one part of the house has an internal bearing wall, and the other - no. For devices above the roof structure in such a use both variants trusses.

Scheme naslonnyh wooden trusses, with emphasis on one run for a hipped roof

Scheme trusses hipped roof removal is used when it is necessary to produce an increase in the eaves. In this case, rafters will rest against the floor joists. When the device hipped roof trusses journalled to floor joists such as the mauerlat element can be completely eliminated from the structural schema. Instead, it provides the use of wooden leveling pads.

Gambrel roof truss system with a bay window

Quite popular in private construction is the construction of the walls of houses with bay windows (tabs). This is a very interesting architectural solution, but projects such homes are complex design and construction design. Bay window you can build, not only during construction, but to attach to an existing building. The protrusion may be a single-storey and multi-storey.

It is worth noting that the most difficult in the construction of buildings such architectural form is the design and installation of a gambrel roof with a bay window. The basic rule - the roof bay should harmoniously maintain the basic structure of the roof, forming a common style. Build oriel roof is very difficult, so not everyone will be decided on the construction of the house. The slightest inaccuracy in the calculations could lead to the fact that the construction will be unreliable.

The structure of the hipped roof with the bay windows of various forms

From that which has a projection shape (rounded, polyhedral, rectangular) and the shape of the roof depends to him. This can be hipped, mnogoschiptsovaya, a gable roof construction or in the form of a hemisphere. Sometimes over a bay window roof erected shpileobraznuyu.

Practiced two variants roof over oriel self roof ridge or a roof integrated with the main structure. For truss bay systems use a material with a smaller cross section than the principal rafters of the roof structure. This is due to the fact that these elements will be perceived less stress.

Technology laying roofing over oriel identical process for coating primary roof. Recommended use tiles, as for a small area with a few ramps required material, the use of which would remain minimal waste. This requirement and meets the asphalt shingles or ceramic. For calculation metal on gambrel roof, you can use a special calculator.

installation of metal

Particular attention in the construction of roofs and bay windows should be given to valley. They are used in the construction of two types - the top and bottom of the valley strip. One covers the unsightly sections, on the other will drain rainfall. Moreover, not recommend professionals to save on the fasteners (screws, nails, pins, plates). They must be purchased in the right quantity and of good quality.

Useful advice!To improve the reliability of the problem areas of the hip design with a bay window, should be used in these places and gaskets.

Learn about the features of the erection of structures can be of installation of video hipped roof with a bay window.

Metal for the gambrel roof with a bay window

Hipped roof with his hands: drawings and photos, sketches and design calculations

Before you begin construction of hipped roof with his hands, you must complete the drawings and make a correct calculation of the whole structure. It would be superfluous to seek help from a professional who has experience in this field and will be able to choose the optimal tilt angle and calculate. Given that the roof construction can comprise broken lines and unevenness accurately calculate all the constituent elements will be difficult.

Tips for drawing and sketches

Before you make a hip roof with his hands, even the most simple design, require the development of the project hipped roof with drawings and sketches. This will help determine the shape of the roof and make it possible to calculate the required amount of materials for the construction. the following guidelines can be used to perform the design:

• measure the height, length and width of the house. According to the findings represent a schematic front end and at home in a convenient scale. Such designs requires a few copies;
• in determining the optimum height hip roof with respect to the house and the roof slope, it is necessary on one of the thumbnails to display several variants of the roof contour. Then choose the most successful, and using a protractor to determine the angle of inclination of ramps future construction;

Draft hipped roofs, where A1 - base width, A2 - laying width, B - lifting height, C - overhang length, D - length of the base

• the next step is the application of the marking scheme provisions naslonnyh rafters - these places mark the point. Divide the length of the wall indicated in the diagram at equal intervals - this is a step between the beams. It can be from 40 cm to 2 m. But it must be borne in mind that quite often installed rafters entail an unnecessary material consumption and a big step between the rafters will cause the amplifier gain elements construction;
• when determining the length of the ridge is necessary to take into account that must be run to connect the pair number of rafters. On one of the thumbnails should be noted equal intervals from each edge of the wall;
• obtained scheme are transferred to the general scheme, then it is possible to calculate the amount of material needed. rafter length is determined by the outside, proceeding from the eaves length (about 50 cm).

Useful advice!To the roof structure was strong and durable, it is necessary to acquire a well-dried lumber.

EXAMPLE layout hipped roof rafters

By the number of rafters can calculate the number of fasteners. In all of the attachment nails will be used. At each rafter foot fall, two mounting brackets. When the blank material should be given a small supply in the event of damage to the material. If the house is made of bricks or blocks, it is necessary to purchase a bar mauerlat device.

The choice of the angle of rays

In determining the angle of hip roof should take into account climatic conditions, which are under construction. If the climate is hot, dry and windy - a bias should be minimized in order to prevent overheating and to avoid additional load. In areas with heavy snow precipitation - the slope is increased to smooth the snow melts.

Furthermore, when choosing the angle hipped roofs should consider the roofing material, each type of which has a slope limit of skates:

• slate - coating used in the roof pitch of 13 to 60 degrees. If the inclination angle is less than 13 degrees, the joints will seep moisture winter - snow fall. This will significantly reduce the life of the roof;
• ceramic tiles - optimum bias for this material: from 30 to 60 degrees. When laying the tiles on the roof, which slope less than 25 degrees, perform measures to improve ventilation and waterproofing;

The choice of the angle of the roof ramps

• metal - when laying this material is the maximum inclination angle is not normalized, the minimum - 15 degrees;
• Shingles - coating is used for roofs with a slope of over 12 degrees. The maximum index angle is unlimited. Material perfectly reproduces the shape of any surface;
• bituminous roofing slate - the sheets of material using an incline of 5 degrees. Maximum value is not present, but the angle of inclination will depend lathing step, and at a slope of 5 to 10 degrees is necessary to equip a solid floor;
• steel standing seam roofing - it fits with slopes of 20 degrees. Maximum limitation of the angle of inclination is absent.

Increasing the angle increases the area of ​​the roof, which would entail additional costs of building material. Therefore, if it is essential to save the materials, it should be taken into account in the figures.

Features of the calculation gambrel roof area

To determine the amount of roofing material for covering the hip of the roof, it is necessary to calculate the area of ​​the coated surface.

Calculation of the area of ​​the hip roof of a private house

To calculate the need the following information:

• take into account the existing roof dormers and chimney, as their presence requires increased consumption of roofing material;
• It is determined by the ramp length from the bottom of the ridge to the edge of the eaves;
• calculates firewall walls, parapets, eaves and other elements;
• The calculations do not take into account abutting canvases, standing seam, protruding elements bars.

Useful advice!If the coating is used rolled material or metal, in determining the surface area necessary to reduce the length of the roof ramps 70 cm.

To obtain accurate data on the roof area, you can seek professional help or take advantage of modern programs that will produce the most accurate calculation. But if you decide to do it yourself, the entire surface must be divided into individual elements, which area easily calculate mathematically, and then the values ​​obtained sum.

The more accurately be defined area, the lower the probability of acquisition of unnecessary material consumption and waste of finance. The amount of materials required for construction, must be fixed at the stage of the project single-storey house with a hipped roof. The cost of these materials includes roofing, so on the correct calculation of the surface area of ​​the roof depends on the construction costs of the house as a whole.

A two-storey house with a hipped roof

For the calculation of the area you need to take advantage of the hipped roof. It should also take into account the technical characteristics of the roof covering (thickness, length) and methods for its installation. The thickness of the material affects the coating weight, and knowing the length and width of the material it can be positioned with the least amount of waste, and connecting lines.

For clarity, one can analyze the use as a roofing material or a ceramic shingles. Ceramic tile - a material superior to the heavy weight of a flexible 5 times. For laying shingles do not require frequent and rafter system crate, but underneath it is necessary to lay vsploshnuyu plywood or other material. Therefore, to determine the value of the entire building and choose the most suitable material, you need to perform calculations hipped roof.

The total cost of construction, without a doubt, will affect the area of ​​the hip roof, but it is worth take into account the complexity of the construction of the structure itself, especially when it comes to the regeneration of the attic premises. The complexity of the calculation will affect items such as dormer windows, air vents, chimneys and so on. D.

For example, we can calculate the area of ​​a hipped gambrel roof. With the drawing of the roof to make the calculations much easier and required values ​​will be more accurate. The diagrams can be seen that the base serves as a roof box, are two ramp isosceles triangle, the other two - the trapezoid.

Driving device hipped hipped roofs, where L1 - length, L2 - width

In this case, the tangent of inclination angle triangular faces is the ratio of h (the height of the roof) to ½ value b (the length of the base of the triangle). Thus, the height of the roof is given by:

h = (b tan α) / 2.

The length of the lateral rafter (e) can be determined by the angle of inclination:

e = b / 2 cos α.

Using the Pythagorean theorem can be determined length nakosnyh rafters (d):

The total area of ​​the entire roof is calculated by summing the squares of all the constituent elements of the surface of the hipped roof, namely the four triangles and two rectangles:

S = 4 (eb / 2) +2 (a-b) e = 2e (b + a-b) = 2ea.

If you want to calculate the area of ​​the hip roof to the square house, then its value will be equal to the sum of squares of four triangular rays.

Apparatus hipped roof hipped

Calculator for gambrel roof area

Due to the fact that not all the strength independently calculate all parameters of roofing, company websites, specializing in the construction of roofs and sales of roofing materials, offer to take advantage of online calculator. It can be used to learn the exact number of sawn timber, insulation and roofing materials and also to calculate the length and the cross section for the construction of trusses of the selected type.

Using the calculation hipped roof-line calculator with drawings and diagrams, it is possible to determine how optimal slope ramps relative of a roof covering, whether the beam cross section can withstand operating wind and snow load on the truss system is in your region.

Before you calculate the hipped roof with help of the program, you must fill in the fields calculator: the length and width base, roof pitch, the length of the side and end overhangs, width, thickness and pitch lathing boards, and specify the grade of wood step rafters. In addition, the load calculation data is entered on the region and type of terrain.

Useful advice!Working in the program note that in front of each field to be filled has a "?" Icon. Clicking on it, you can find explanations on specific input parameters.

Design gambrel roof design

After processing the online calculator entered data, you will receive information on compliance with the standards specified by you used slope roofing. If a discrepancy is found, the program will offer replacement options. In addition, you will receive information about the lift height, the length of the ridge hipped roof, the weight of roofing coating amount of web material with the length and width of the roll and the desired overlap when laying.

calculator conclusions also include the area of ​​the roof surface (this will include the sum of areas of all the rays, including overhangs desired length), and the number of roofing underlay material which is required for the construction of roof. The calculated value of the maximum load on the system allows for roof trusses construction roofing cake weight and the data entered on the snow and wind loads.

In addition, the program does the calculation of roof system gambrel roof: will give information on the number and size of the side and diagonal trusses, and offer the recommended size of the minimum cross section for rafter system, the choice of which provide proper structure strength.
Using data calculator of the optimal number of rows of boards and battens can avoid a possible waste of material and time costs for excessive trimming of lumber. In addition, you will receive information about the number of boards in cubic meters and kilograms.

Using the program for the gambrel roof, you will not only save time and money, but also get practical recommendations based on the standards SNIP "Loads and effects" and TAP 45-5.05-146-2009 (Wooden design. Building design standards).

How to mount the steps hip roof with his hands: video editing

Assembling gambrel roof truss system is no simple task, but with strict adherence to the project and practical advice of professionals to cope with the construction as possible. The key to high-quality installation is the most correct and accurate calculation of the scheme, following which you can make the right cuts rafters and install all the design elements. For example, you can see the video editing stage, having found it on the Internet.

Instructions for the construction of hipped roof with his hands

Before you make a hip roof by yourself, you should become familiar with useful recommendations, following which do not have to doubt the reliability of the design:

• intermediate truss legs have a steeper slope than nakosnye rafters. In this connection for them using the board with the parameters of not less than 5x15 cm;
• fixing short rafters made not to the ridge pole, and to nakosnym elements. Angles of short and intermediate rafters coincide;
• Timber used for the ridge pole and rafters must have an identical cross-section. It is due the strength will be provided subject to the rules of design. Otherwise it is likely deformation;
• intermediate the rafters are fixed to the edge of the ridge beam and to the top of the binding;
• height hip roof can be any, but if the slope is very slight, it is necessary to use additional studs, bearings;
• to extend the life gambrel designs must use softwood lumber, predried and having no defects such as knots and cracks. Also, before starting work, all the wooden elements are treated with antiseptic compositions.

Mounting roof system gambrel roof

Marking the future design

Construction gambrel roof begins with a markup object.

Step 1. From the end of the housing is necessary to identify the axis of the upper piping walls.

Step 2. Further it is necessary to determine the half thickness of the ridge run and identify the location of the first member of the roof truss system.

Useful advice!To avoid errors in the marking of the object, it is recommended to use a special gauge rod, on which all the required dimensions are marked. It can be cut, for example, of strips of plywood. Recommended width rack 5 cm.

Step 3. Attach one end of the rail to the planned line, and the second place along the side walls. So it is possible to identify the location of a point intermediate rafter.

Step 4. To determine the length of the truss overhang is necessary to place the timber at one end to an outer corner, and another - for roofing overhang.

Step 5. To determine the location of the central rafter, you must move the striper rail to the edge of the side wall and to fix the place of the central member truss arrangement system.

This procedure should be applied to all four corners of the structure. Thus it will identify the installation location intermediate the ends of the rafters and a ridge run.

The design of the roof trusses hipped

Calculation of the rafters system

After marking of the need to calculate the rafter system.

Step 1. With the rack is necessary to determine the horizontal projection of the intermediate rafter. From the table, locate the appropriate standards of your case the roof slope and multiply values.

Step 2. Measure the length of the rafter, and the measurement should be done at the bottom line of the sample space on the ridge pole to sample at the bottom of the legs.

Step 3. To determine the length of overhang must horizontal projection rafters value multiplied by a correction factor from a table of proportions.

Table proportions and correction factors:

Useful advice!The calculations can use the Pythagorean theorem, wherein s² = a² + b², where a and b - respectively vertical and horizontal projection.

Step 4. Next, you need to calculate the angle rafters. For fixing rafters to the ridge beam, the ends of these elements are made oblique slices. In turn, the ridge pole also has a double bevel, whereby the angle rafters securely attached to it.

Calculation nakosnyh rafters in the following order:

• from one of the housing angles determined by the length of the rafter;
• calculated projection, which equals the sum of the squares of the central projection of trusses;
• the resulting number is multiplied by the correction coefficient from the table. This will be the length of nakosnogo rafters.

Wooden rafters system gambrel roof

Installation of rafters

Next, you install rafters.

Step 1. First the ridge beam, which is fixed on the supporting racks. On the central beam elements are fixed by mounting struts.

Step 2. Nakosnye installing rafters, check that the length of all the elements were identical. Carefully hip joints, nakosnye rafters and ridge beam.

Step 3. After you have installed nakosnye legs should begin the installation of ordinary rafters that have steps of about 60 cm. Fixing is carried out by ordinary trusses mauerlat and by notching the ridge. To mount was reliable, use screeds and beams.

Useful advice!When installing ordinary rafters avoid their contact with the pins that secure mauerlat to the ends of the walls.

Step 4. Next to nakosnym rafters are attached short rafters (narozhniki). Through Narozhnyi elements nakosnye rafters will be associated with mauerlat. The position of the rank and file and Narozhnyi rafters should be perpendicular to the ridge beam.

Installation of rafters hip roof

Strengthening the construction of the roof trusses hipped

There are several variations of truss construction gain:

• on the design of the corners diagonally attached to the vertical stand Sprengel, who will act as an additional support for nakosnyh rafters. Is fixed to the Sprengel mauerlat;
• Tightening of the board has a rack that will be a support for the intermediate rafters;
• if nakosnaya rafter foot is long, use it for the manufacture of bonded or composite beams.

ventilation device

An important stage in the construction of hipped roof is a ventilation device. The roof is exposed to destructive influences not only the outside but also from the inside, where there may be condensation. This is due to the temperature difference between the outer and inner surface of the roof. Quality ventilation of roof space will keep the roof surface for years to come.

Scheme ventilation underroof

To ensure an adequate level of ventilation of the space under the roof, it is necessary to arrange a film wind protection opening to the air. It must be located at a short distance from the ridge pole. When using the binder for wood wind, it is laid with a gap of 3 mm. In the case of plastic material - the perforation practice.

For those cases when the wind protection roof mounted without play, it can be embedded in conventional vents with a diameter of 50 cm. Place them follows the entire length of the windshield at a distance of about 80 cm from each other. After the execution of these works can proceed to the arrangement of insulation, waterproofing and laying of roofing material.

Apparatus hipped constructions - technically difficult and laborious process. To do the work necessary in the event that you have enough time and expertise in this area. Any inaccuracy can lead to unnecessary consumption of materials and the rise in the cost of construction. If you doubt their abilities, it would be appropriate to seek help from these professionals.