Construction and installation of the rafter system of the hip roof

 Construction and installation of the rafter system of the hip roof

Hip roof is one of the types of hipped roof, its structure includes two main trapezoidal and two end triangular slopes, forming a closed surface with a common ridge girder. If the side slopes are located over the entire area from the ridge to the eaves, then the roof is called hip, and if they do not reach the eaves - half-hip.

Types of rafter structures for a hip roof

If the rafter structure rests only on the main walls of the building, it is called hanging, and if it has additional anchor points due to the walls inside the house, then it is called layered.

If the rafter system rests only on the external load-bearing walls of the building, it is called hanging

  1. The hanging system is usually used for the construction of small buildings that do not have internal load-bearing walls. In this case, the vertical beams that support the rafters are attached to the ceiling beam.
  2. The overhead system, which has several anchor points, is easier to assemble, so it can be used to erect large buildings with a large number of interior walls. In their upper part, a support bar is laid horizontally, on which the vertical posts supporting the rafters are then fixed. Usually, the supports with their upper part are nailed to the ridge bar. A frame is formed inside the roof, which has right angles, due to which it can withstand heavy loads even with the maximum roof area.

    The vertical racks of the layered rafters rest on the intermediate walls, and in the upper part they are attached to the ridge girder beam, due to which a rigid rectangular frame is obtained

If the building has two main walls, then a tension beam is laid at the top of the vertical posts, which reinforces the rafters and distributes the load over the entire area of ​​the vertical support posts.

To create a hip roof, the layered rafter system is most suitable, since it has a greater degree of strength and makes it possible to lighten the roof structure, evenly distributing its weight over the entire frame of the building.

The rafter system of the hip roof can have several structures that are different in the way of installation, each of which assumes the presence of certain features during assembly.

  1. Traditional rafter system. In this design, the diagonal ribs rest on the support beam of the main ridge and the overhangs are at the same height. Such a system consists of two isosceles triangles and two trapezoids.

    The rafter system of a classic hip roof consists of two triangles and two trapezoids

  2. Tent system. This design does not provide for the presence of a supporting ridge beam, because it is arranged over buildings of a square shape and consists of four identical ramps of a triangular shape. All diagonal edges converge at a common point, and short crochets are connected to them. Only professionals can make a reliable ridge knot of a hipped roof.

    The hipped roof rafter system consists of four triangular slopes, converging with their upper parts to one point

  3. Half-hip design. Such a system provides for the presence of vertical parts in the gable slopes, into which standard windows can be installed.

    The semi-gable roof has vertical sections of gables into which ordinary windows can be inserted

  4. Sloping roof (mansard). This is the most complex and time-consuming hip roof system, since all slopes have a different shape and area and diverge from each other at different angles. Such a roof allows the most efficient use of the area under the roof and the creation of additional living quarters on it.

    A broken or mansard roof structure allows you to equip full-fledged living quarters in the under-roof space

How to calculate a rafter system for a hip roof

When calculating the structure of the rafters of the hip roof, the following factors must be taken into account.

  1. The degree of regional wind load. The larger it is, the smaller the roof slope angle should be and the stronger the system. The main support rafters should be made of thick beams.
  2. The amount of precipitation. The more precipitation falls annually, the steeper the roof slopes should be in order to avoid a lot of pressure on the rafter structure.
  3. Material for covering the roof of the house. Depending on the type and weight of the roofing material used, the sheathing system is selected. This factor is taken into account at the stage of developing a house project.
  4. Thermal insulation of the roof. The width of the insulation, the grade and thickness of the timber are taken into account when calculating the step of installing the rafters.
  5. Roof slope. The slope of the roof affects the choice of topcoat material.

Each roofing material has its own permissible range of roof slope angles

The angle of inclination of the roof slope determines the position of all rafters. The installation location of the intermediate rafters is calculated as follows:

  1. The centerline is drawn on the top beam of the side wall.
  2. The middle of the ridge beam is determined in terms of thickness and the line of location of the first of the center intermediate rafters is beaten off.
  3. The end of the measuring strip is connected to the line of the location of the previously marked center support rafter.
  4. At the other end of the plank, the line for the location of the inner contour of the end wall is striking.
  5. The point that will be obtained in the previous step will be the installation site for the intermediate rafter.

The relationship between the size of the rafters and the length of their laying (horizontal projection) is determined using the correction factor, the value of which is directly proportional to the angle of inclination of the ramp. If you multiply the size of the laying by this factor, you can determine the exact length of the rafters.

Table: correction factors for determining the length of the rafters

Roof slopeCoefficient for intermediate raftersCoefficient for corner rafters

Formulas for calculating the structure of rafters

In the process of developing a project for any roof, you should determine the exact angle of inclination of the slope, which is necessary for all subsequent calculations.

Calculation of the area of ​​the hip roof

The roof area is calculated as follows:

  1. We determine the height of the ridge by the formula h = d / 2 · tg α (where d is the width of the building, α is the slope of the slope, h is the height of the ridge).
  2. We calculate the value of the side rafters according to the formula c = d / 2 · cos α.
  3. Find the length of the diagonal rafters l = √ (h2 + d2/4).
  4. We consider the area of ​​the roof, for which we add up the areas of all structural elements (two trapezoids and two triangles):
    • area of ​​the triangular slope S1= 1/2 d / 2 s;
    • area of ​​the trapezoidal slope S2= 1/2 (b + k) e, where b is the length of the cornice, k is the length of the ridge run, e is the height of the trapezoidal slope;
    • S = 2 (S1 + S2).

To determine the area of ​​the hip roof, it is necessary to use the area formulas of simple geometric shapes: a triangle and a trapezoid

Calculation of the distance between the rafters

Most rafter systems are created with a pitch of 1000 mm between two rafters. The minimum allowable pitch is 600 mm.

  1. We choose the approximate distance between the rafters, guided by standard dimensions (for example, take this parameter equal to 0.8 m).
  2. We measure or take the length of the slope from the design documentation. Let's say it is 12 m.
  3. Divide the length of the ramp by the previously selected value of the rafter step, round the total up and add 1. We get 12 / 0.8 + 1 = 16.
  4. We divide the length of the slope by the number obtained in the third paragraph. The final step of the rafters will be 12/16 = 0.75 m = 75 cm. The resulting value will be equal to the distance between the central axes of the rafter logs.

Preparatory work

The drawing of the rafter system is a prerequisite for the construction of this type of roof, since there are no identical schemes that are ready for direct use without taking into account the specific type of building and the place of its construction.

The more complex the roofing system, the more accurate the calculations should be, since they will affect not only the quality of the work carried out, but also their cost.

The drawing of the main structural units must accurately indicate the dimensions of all elements of the rafter system, the location of the points of abutment of the diagonal racks to the ridge beam and the attachment points of the rafters to the Mauerlat.

Tools required to assemble the structure:

  • construction level;
  • hacksaw;
  • large hammer;
  • long tape measure;
  • construction cord;
  • stapler;
  • electric drill;
  • riveting machine;
  • metal shears;
  • nails;
  • measuring bar.

Materials for work:

  • Mauerlat - timber 100x100, 100x150, 150x150;
  • rafters - a board with a section of 50x150, a bar 100x100 or 150x150;
  • girders, skate bar and sunbeds - 100x100, 100x150, 100x200 bar;
  • crossbars - boards 50x100, 50x150;
  • racks, truss support elements - timber 100x100, 150x150;
  • struts, filly - boards 50x100;
  • wind boards, end boards, hemmed boards and wind beam - 20x100, 25x150;
  • crate - boards 25x100, 25x150;
  • solid sheathing - sheets of plywood or OSB 12-15 mm (the need for continuous sheathing is determined by the type of roofing material);
  • steel mounting plates;
  • nails, screws, anchors.

    When installing the roof, metal fasteners are used, which are necessary to give the structure additional rigidity

When installing a hip roof on a house from a bar that shrinks, experts recommend using special floating fasteners for rafters to compensate for the movement of the crowns.

When installing a rafter system in a wooden house, it is recommended to use a sliding rafter fastening system, which compensates for the deformation of the building when it shrinks

Video: ensuring the rigidity of the hip roof

Features of the rafter system of the hip roof

All types of hip roof truss system have identical parts, which create the frame of the structure:

  • the ridge beam is necessary for the construction of a classic roof, as it carries the main load. All diagonal support rafters are attached to it;
  • diagonal or side oblique ribs and corner rafters are attached to the side of the ridge bar at a certain angle to create the sides of an isosceles triangle;
  • the central rafters are mounted to the ridge girder, creating a trapezoidal edge of the ramp. Between them are beams to create an intermediate row;
  • ordinary rafters are necessary to create a pitched plane in the form of a trapezoid. The step between them is determined by the calculation that was given above;
  • The rafter is an additional element that is nailed to the diagonal rafter, creating an overhang of triangles and corner trapezoid elements.

    Oblique rafters set the shape of the roof slopes, vertical racks remove the load from the ridge run, and struts, braces and sprengels give the system the necessary rigidity

Video: collecting rafters

Technology for creating a hip rafter system

Since a large load is imposed on the roof truss structure, all nodes and connections must be made in strict accordance with the technology, otherwise the roof will not be able to fully perform its functions.

Installation of main units

Installation of units is reduced to the following steps:

  1. We prepare the rafters. We determine the angle of inclination of the rafters, the length of the short supports and slanting rafters, which carry a significant load. In order to obtain all the elements of the required length, we use the method of connecting overlapping boards. To do this, we lay two boards on top of each other with an overlap of 1 m and fasten them with staggered nails. This is the simplest and most durable way to splice rafter legs.

    The most durable and reliable method of splicing rafter legs is overlapping

  2. We fix the Mauerlat. We mount the timber along the entire perimeter of the building walls in the upper part. We connect the timber with an overlap using a large number of attachment points to the base of the load-bearing walls. We fasten the joints with metal staples.

    The Mauerlat beam is attached to the upper end of the wall using anchor bolts

  3. We lay a layer of roofing material between the wall and the timber to create a hydro-barrier. In brick, aerated concrete, foam concrete and wood concrete houses, a reinforced concrete belt with pre-fixed pins for installing a bar is poured under the Mauerlat. The pin must be at least 10 mm in diameter and protrude about 30 mm beyond the belt. The pitch between the pins is from 1 to 2 m.

    A layer of roofing material creates a hydro-barrier between the Mauerlat and the wall made of moisture-absorbing material

  4. We install the bench - the central beam between the two short sides of the Mauerlat to provide additional strength under the rafters. Such a run is necessary to create a large hip roof.
  5. We mount the support posts. They act as supports for the ridge run.

    The support posts are mounted on the bed and serve as supports for the ridge run

  6. We mount the ridge beam. When installing the ridge of the hip roof, accurate measurements should be taken, since the entire roofing system will be held on it. We check the accuracy of its installation with a level in height.

    Carrying out work on the device of the ridge beam requires accurate measurements, since it bears the greatest load in the hip roof system

  7. We nail the rafter legs. We mount the central rafters, and after them the diagonal ones. During installation, we rest the lower part of the beams against the Mauerlat. This can be done in two ways: with a notch or with support legs. In the first case, we cut out a groove in the Mauerlat, insert the rafters into it and fix them with metal corners. In the second case, we simply put the rafter on the Mauerlat and put a block with an oblique cut under it. We also fix them with a metal corner.

    The rafter legs can be attached to the Mauerlat in two ways: with a notch and on a support bar

  8. We make the assembly of the node on the ridge beam using the "half-tree" method. To do this, we cut a notch at the end of the rafter legs, which should be equal to half the thickness of the board. Then we connect these grooves to each other and fix them with nails or pins. It turns out a strong ridge knot. For greater strength, we fix all the nodes with steel corners.

    To create a strong ridge knot on the hip roof, the "half-tree" cutting method is used

  9. There is a lot of pressure on the diagonal rafters, so we reinforce them with the help of racks, which we mount on the floor or install struts at a certain angle. You can use a sprengel in the form of a T-beam, turned 180 °.

    Sprengel is one of the auxiliary elements to ensure the necessary rigidity of the rafter system, which transfers part of its load to the Mauerlat

  10. We mount ordinary rafters in the same way as the central ones, which form the edges of the trapezoidal structure. We support the bottom of the beam and fasten it to the Mauerlat, and we rest the top against the ridge beam.
  11. We install wedges, which we make from a solid board. In the place of their attachment to a long rafter, we make special cuts or put support beams and provide the necessary strength with the help of metal fasteners. To simplify the work, the beads can be installed at random.

    Narodniks are fastened with a cut into the rafter beam and installed in a staggered manner

All wooden parts of the truss system are treated with special refractory and antiseptic agents before assembly.

Video: hip roof truss system

The creation of a hip rafter structure is a long and complex process that requires attention to each specific detail. But if you carry out all the stages of work correctly and accurately, then as a result you will get a beautiful, durable and reliable roof for your home.

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Roof windows

When planning an attic, it is worth considering the recommendations of SNiP. They recommend that the window area be at least 10% of the floor area. So if the attic will be divided into several rooms, there should be a window in each.

Roof skylights

Of all the methods shown in the photo for arranging roof windows with an attic, an inclined installation is the easiest to implement. In this case, it is necessary to ensure the proper degree of waterproofing of the junction, as well as to use special models with a reinforced frame and reinforced glass - the load on the surface can be significant.

Pros of a tilted roof window:

  • more light, less sharp boundaries of light and shadow
  • the surface of the roof remains flat, its relief is not complicated
  • relatively easy installation.

When planning such a window, it must be remembered that its area increases with an increase in the angle of inclination. At what height it is more convenient to install such a window and how its height in centimeters increases depending on the tilt, look at the photo.

The steeper the slope relative to the floor, the lower the window height should be

The width of the window frame should be 4-6 cm less than the step between the rafters. Then it can be easily installed without disturbing the structure of the frame. If the window is wider, it is necessary to make a reinforced beam above it, calculate the load.

If you need to have a larger window, it is easier to put two narrow ones side by side. They look no worse than one big one, and there will be fewer problems.

Two windows side by side look no worse than one wide one

When installing a dormer window, the geometry of the roof becomes more complicated: a valley appears on top and on the sides. Because of this, the rafter system becomes more complex both in planning and in assembly. The complexity of the installation of the roof covering also increases. All valleys are where leaks are most likely to occur. Therefore, everything must be done very carefully here. In regions with a large amount of snow, it is advisable to install snow holders above such windows: so that during a sharp descent they will not be demolished.

Arrangement of a vertical window-dormer in the mansard roof

The advantage of such a window: you can stand near it in full growth. But they let in less light, the relief becomes more difficult and the roof becomes more problematic.

A recessed window is usually used if you make an exit to the balcony through it. In other cases, this method of arrangement is not the best option: little light enters, the shadows turn out to be very deep, which is tiring for the eye, the geometry also becomes more complicated, although not to the same extent as in the previous version.

The easiest way is to make a window at the end of the attic. In this case, you do not need a reinforced frame or reinforced glass. It is quite enough just high-quality glasses. It is this option that can most often be seen in summer cottages: this is the most inexpensive option, which is easily implemented with your own hands.

Read about the gable roof device here.

Hip roof device step by step

Like any serious structure, a hip roof is erected with your own hands in several stages:

Creation of a project with the analysis of load-bearing structures.
Logging and other roofing materials.
Installation of the rafter system.
Laying the coating with insulation (if necessary).

Design advice. So that you do not have to worry about the reliability of the building, it is strongly recommended to entrust the design work to engineers, regardless of financial costs. They will calculate all the parameters - the step of installing the rafters, their section, the number of struts and puffs in accordance with the weather conditions in your area.

Above, as an example, a drawing of a four-pitched roof with layered trusses covering 2 spans of 4.5 m is shown. The length of the main rafter legs is 6 m, the height of the ridge is 4 m, the angle of inclination is 41 °. This structure can be taken as a basis if the width of the building does not exceed that indicated in the drawing (9 meters). Consider an important point: the more the hips are tilted, the greater the load is experienced by the women and the central ridge knot where they rest. In this example, the hips are best positioned at an angle of 45-50 °.

The most difficult thing in the construction of hip roofs is the correct installation of the splicing units for corner rafters with a Mauerlat and the upper chord of trusses in different structures. This is another reason to consult with the designers who develop the junction joints individually. So that you understand what is at stake, we present the drawings of the upper support unit, where the hip rafter leg is adjacent to the ridge.

Some designs do not provide for the manufacture and installation of a ridge run between trusses. Then the hip ribs are attached to a tightening and additional struts, as the drawing prescribes:

The lower support node of the leg on the Mauerlat and the splicing of the rafters looks somewhat simpler, although in reality it requires careful sawing of the boards at various angles, which is reflected in the diagram.

For a visual acquaintance with a more complex system, where the hip is combined with the bay window, we suggest watching the training video:

Selection of lumber

Before making a hip roof truss system, you should choose a high-quality and dried wood. In terms of price - quality, the most suitable option is a coniferous tree - spruce, larch or pine. Pronounced knotty, rot and traces of the vital activity of insects - pests are unacceptable.

We present the most "popular" sizes of lumber used for the phased construction of hip roofs:

main rafter - single board 50 x 200 mm or double 40 x 150 mm
Mauerlat: minimum section - 100 x 150 mm, optimal - 20 x 20 cm
wives - board 5 x 15 cm
purlins - timber 50 x 150 or 50 x 200 mm
struts, crossbars - board 25 to 50 mm thick
racks - a bar 5 x 10 cm.

A set of mounting plates and corners will also not be superfluous.

Note. If the design engineers calculate the roofing structures for you, they will also draw up a specification of all materials with dimensions.

Planks with a thickness of 25-32 mm are traditionally used for the lathing for laying corrugated board or metal tiles, and 5 x 5 cm bars are used for the counter-lattice.

Installation of a strapping bar on walls

Unlike gable roofs, where the Mauerlat is installed on the side walls, under the hips, the harness is made around the entire perimeter. The exception is frame, log and log houses, where the upper wall girder or the last tier of logs acts as a mauerlat. Then grooves are made in it, where the rafter legs are inserted, as shown in the photo.

On the walls of light cellular stone - aerated concrete and foam concrete - a reinforcing reinforced concrete belt is arranged before laying the piping. Mounting pins are embedded in it, onto which a strapping bar is subsequently put on. The step-by-step order of work looks like this:

Installation of panel formwork, binding of the reinforcement cage with embedded parts and pouring the belt with concrete mixture M200.
Waterproofing the concrete surface with roofing felt or bitumen primer.
Installation of a bar and its fixation on hairpins.

Mauerlat corner joints are made by cutting in half a tree. In the same way, the timber is built up in length if the standard size of 6 m is not enough. Also, horizontal struts are made at the corners or iron brackets are driven in, which do not allow the bars to disperse under the load of the main and hip rafters.

Advice. Be sure to treat all wooden parts with an antiseptic and flame retardant. One protects the wood from decay, and the second increases its fire resistance.

Assembling the rafter system

It is customary to install large roof trusses on site, because it will take twice as many workers to lift them from the ground. In wooden houses, the first step is to install all the ceiling beams, and temporary flooring is arranged along them. For the installation of a high ridge, scaffolding will also be needed.

The phased assembly of the hip roof construct is performed in the following order:

As with the construction of a gable roof, the first step is to place the central supports, where the ridge girder is attached.
The installation of the main rafters is carried out, which are cut from above and below at the desired angle. On the ridge, the opposite rafter legs are displayed in one plane and fastened with steel plates on self-tapping screws (yellow, not black). The beams are fixed to the Mauerlat with corners.
After installing the main trusses, tighten them with ledgers and struts according to the drawings, using bolts for fastening.
Install ribs - extreme hip rafters. Their connection with the ridge and strapping beam is carried out according to one of the schemes proposed above.
Saw off and nail the beads to the frame. Each of them is cut at different angles, determined by measuring at 4 points (along each edge of the board).
If necessary, secure the filly to provide an overhang of 0.5 m, and hem the cornice with boards.

Advice. Since the ribs of the hip are long, they need to be built up and additional supports should be installed. Make the joint near the ridge, where the load on the roof is less, and mount the supports closer to the Mauerlat.

How the elements of the hip structure are attached in reality, see the following video:

Laying the topcoat

This final operation is carried out according to the traditional technology, which includes ventilation of the roof space and the installation of a waterproofing layer made of a diffusion membrane. The latter does not allow moisture to penetrate from the street into the attic, at the same time, the film freely passes water vapor outside. The difference from the covering of ordinary gable roofs is one: along the fracture lines (on the ribs of the hips) additional cover strips are placed.

The covering material is laid in the following order:

The rafter system is completely covered with a diffusion membrane. The canvases are rolled horizontally with an overlap of at least 100 mm, starting from the bottom. The joints must be glued with tape.
The film is nailed to the outer edges of the rafters through 5 x 5 cm counter-lattice bars, which provide ventilation under the metal tile or other material.
Sheathing boards are nailed perpendicular to the direction of the rafter legs. The installation interval depends on the selected coating, and for soft tiles, the filling is continuous.
Roofing material and all fittings are mounted on the ends of the roof, as well as around ventilation and chimneys.

Note. The bars of the counter-lattice, nailed to the rafters, should not become an obstacle to the ventilation air. Therefore, they are specially shortened to a length of 2-3 m and nailed with a gap of 5-10 cm between adjacent elements.

Warming of the hip roof is done both during the installation of the coating and after it, the main thing is to assemble the correct "pie" shown in the diagram. In the first case, the mineral wool is laid on top, under the waterproofing, and in the second - from the inside.

Dimensions (edit)

Pairing boards is an excellent practice, which allows you to get a large block even from small elements and make, for example, a part 9 meters wide or more. When calculating the permissible and justified length, width or thickness of the board, a balance must be observed between strength and the load generated, because a strong structure inevitably turns out to be heavier. The smallest section, which is considered acceptable according to technical requirements, is 5x15 cm.It is worth using it to save money when constructing secondary buildings.

When constructing long spans, it is worth choosing boards of 15x15 or even 25x10 cm for the rafters. An even larger section is justified only for very large-scale roofs (for example, on an apartment building, above a solid shopping pavilion and similar buildings). Regulatory parameters can be useful, but they do not reflect the climatic specificity of certain areas.

Therefore, professional builders unambiguously agree that calculations should be carried out every time a new structure is created.

The optimal thickness of the boards for the formation of rafters ranges from 40 to 60 mm. When building a roof over utility structures of secondary importance, it is allowed to save money by using wood with a thickness of 35 mm. But above residential buildings, it is recommended to put solid rafters from boards with a thickness of at least 50 mm. When the board lengthens, its required width also increases.

The most accurate calculations are made using special software.

Sometimes the recommended cross-section of the rafters can be reduced if special slopes are used.

Calculation of the area of ​​the roofing

This calculation comes down to determining the areas of the trapezoid (slope) and triangle (hip).

Area of ​​a trapezoid and a triangle

Let's do the calculation for our example.

1. The area of ​​one hip with CD = 3.52 m and AB = 8.0 m, taking into account the overhang of 0.5 m:

  • S = ((3.52 + 0.5) (8 + 2 0.5)) / 2 = 18.09 m 2

2. The area of ​​one slope at BL = 12 m, CF = 7.044 m, ED = 2.478 m, taking into account the overhangs:

  • S = (2.478 + 0.5) ((12.0 + 2 0.5) + 7.044) / 2 = 29.85 m 2

Total roof area:

  • SΣ = (18.09 + 29.85) 2 = 95.88 m 2

Advice! When buying material, consider cutting and inevitable losses. The material produced by elements of a large area is not the best option for hip roofs.

Basic diagrams and elements of the rafter system

As we wrote, the hipped roof is geometrically a pyramid, so all calculations are carried out based on the rules that apply to the pyramids and triangles that make up it.

Geometric image of a hipped roof

Main elements

In order not to be confused in the future with the terms, we will name the main elements of the hipped roof rafter system, schematically shown in the figure below, and link them to the geometric image of the hipped roof in the form of a pyramid.

Hanging rafter structure

  1. Mauerlat. Roof base and support, especially in hanging rafters. It is located around the perimeter of the building (ABCD), rests on the walls or is mounted on their outside. For the Mauerlat device, a large section bar is used.
  2. Slant rafters. Roof corners converging at a central point to form a pyramid. On the pyramid diagram (excluding overhangs): AK = DK = CK = BK = Lн. Longest rafter legs in construction.
  3. Ridge knot (K). The most difficult knot in a carpenter's design. If the base of the house is not square, but the ridge forms an edge, the hipped roof transforms into its "sister" - the vald roof. In a structure with layered rafters, the KF (H) section is the central support.
  4. Central rafters. They converge in a ridge knot with nipple rafters. They are the height of each slope, which is an isosceles triangle.On the pyramid diagram (excluding overhangs) - a segment KE, length Lц.
  5. Narodniks. These are shortened rafters running parallel to the central one in both directions.

Now consider constructions with layered rafters.

Tie-free construction with layered rafters

Along with the already indicated elements: the oblique (1) and central (2) rafters, as well as the ridge (3), new elements appear. The central support (rack) or headstock (4), which is supported by the puffs (5), connecting the Mauerlat diagonally. This is an embodiment of a rack that is not based on the masonry, but on an element of the rafter system.

Reinforced rafters with transoms

In the absence of central rafters and to strengthen the ridge knot with the headstock (2), it is complemented by the crossbars (3) connecting the oppositely placed slant rafters (1) in pairs (see the figure above).

The first stage in the construction of a roof is to determine the purpose of the roof (covers the attic floor, attic, etc.), the choice of roof material (depending on this, a list of materials for construction will be determined), taking into account the atmospheric conditions of the place where the roof will be used (wind, rain , snow).

Choosing a hip roof will give the structure more resistance to rain and make it more durable (the rafter system is more reliable). The main difference between this type of roof and a gable roof is that it has two triangular roof slopes instead of side gables.

When choosing the angle of inclination of the slopes, one should take into account the level of precipitation and wind characteristics of the terrain. With low and medium average annual precipitation, it is recommended to choose an angle in the range of 4-40 degrees. With heavy snowfalls and lingering rains, the recommended optimal slope angle of the slopes is within 40-60 degrees.

The roofing material can be: roll roofing, shingles or metal shingles.

Depending on all of the above nuances, the thickness and other parameters of the wooden component of the hipped roof will be selected.

The end result of the first stage is the creation of a scheme for the future roof, on the basis of which the construction will be carried out.

We will describe the further technology of how to make a hipped roof with our own hands.

The second stage is to build the base for the roof. The base is used to evenly distribute the load from the roof to the load-bearing walls. The construction of a hipped roof assumes a base that you can build on your own - a wooden Mauerlat and beds. Waterproofing is required under the base to extend the life of the roof. A Mauerlat is placed on the hydro-barrier along the outer contour of the building (the size of this bar varies, either 100x150 mm, or 50x150 mm.).

Legs - a bar located in the plane of the base of the rafter system at the same distance from the two side Mauerlats. It serves as a supporting element for struts and struts, therefore it is laid on load-bearing partitions (see drawings of a hipped roof). Large roof structures can provide several beds.

The third stage consists in the direct installation of the roof frame (base, rafters, lathing).

The construction of a roof in a house with or without existing ceilings is structurally different (in this case, there is no need to lay the floor beams on which the supports will be installed).

The installation of the racks (vertical supports of the roof frame) should be approached with special care. The installation angle (90 degrees) must be precisely maintained. At the slightest deviation, further deformation of the roof is possible. The step of mounting racks is up to two meters.

The device of the hipped roof of the house consists of four planes (slopes). Two trapezoidal and two triangular. Trapezoidal rafters will be formed by side rafters, hip (triangular rafters) - by slant (diagonal) rafters.

The support of the rafters at the top of the frame is carried out into the ridge beam (girder). This bar goes on top of the vertical posts (groove connection with the posts is possible). The distance between the rafters is from 50 to 150 cm (according to the roof plan). The recommended width of the rafter board is 150 mm.

The frame is fastened using corners and steel plates with self-tapping screws (nails). To strengthen the resulting structure, diagonal supports, struts, wind beams are used. They increase the load capacity of the system.

Waterproofing is laid on top of the rafters. Then a counter-lattice is made (bars that are attached to the rafters over the waterproofing). It is needed to create a ventilation duct between the roofing material, lathing and waterproofing. This will allow moisture to be removed quickly and efficiently. Next, the lathing is performed - the horizontal boards are attached from the bottom to the very top to the counter-lattice (see the diagram of the hipped roof device).

The last step is the installation of the roofing material. Installation is carried out depending on the parameters of the material. An example of metal tile installation.

Thus, the installation of a hipped roof is a rather laborious process that requires a careful approach. For a deeper understanding of the building, you should view photo and video materials.

Watch the video: How To Calculate And Layout Hip And Valley Roof Rafters Using Math Formula And Framing Square