Gable roof: rafter system for metal tile

The construction of a gable roof for private houses is chosen most often, as it is the best option for ease of installation and ease of use, in strength and reliability, as well as in style. The gable roof is called gable in another way and has two ramps that can be arranged with respect to each other at the same or different angles, that is, the front can be an isosceles or versatile triangle. The latter option is increasingly found among new buildings, as it becomes a fashionable style solution. And, in addition to originality, such a roof has some positive features that simplify its operation.

Gable roof: roofing system for metal tiling

A similar type of rafter system can be used for all types of roofing materials, but the crate attached to the rafters for each of the coatings has its parameters.

Gable roof: the rafter system for metal tile has its own characteristics, it must be carefully studied and calculated beforehand, before purchasing materials and carrying out its installation. Let's try to understand these issues.

Types of gable roof designs

To begin with, it is necessary to understand what kind of contruktsii pitched roofs there are, as it is necessary to choose the most suitable for a particular structure.

• Simple equilateral saddle structure

The simplest version of a gable roof - symmetrical ramps

This version of the gable construction can be called the traditional and the most used because it is easy to install and maintain, and also has durability and reliability.

Symmetry in this system helps to achieve uniform load on the Mauerlat and load-bearing walls. If the cross-section of the beam is correctly selected for the truss system and mauerlat, these parts will provide the safety margin necessary for the long-term operation of the roof. Additional reliability of the structure will be provided by properly installed racks, struts and puffs.

The disadvantage of this system for arrangement inside the attic space of the rooms is that after the installation of walls and ceiling, a large area is occupied by blind areas in the corner areas of the structure that remain unoccupied.

• Simple asymmetrical gable construction

Very interesting houses with an asymmetrical gable roof

Asymmetrical gable construction differs from the traditional system in that its slopes are located at different angles. So, one of them is usually more than 45 degrees, which makes it possible to increase the useful area of ​​the attic space, in which it is possible to equip the living space, naturally, with proper insulation.

Another important advantage of this design may be a smaller surface area, which is recommended to plan on the leeward side of the building, where a large amount of snow always collects on the roof. Small in size, but with great steepness, the ramp will not hold up large snowdrifts on its surface.

The disadvantage of the asymmetric design can be attributed to its more complex calculation to achieve an even distribution of the load on the walls of the house.

• Broken gable

One ramp is "broken" to block the side of the house

This gable roof system can be called a rarity, although due to this arrangement of skates in the attic space a large room is formed that can be used for residential or utility rooms.

In addition to such a rafter system to the broken gable construction can be attributed to the mansard version of the installation of rafters.

Both slopes are "broken" - a clear win in the useful area of ​​the attic space

The roofing rafter system is able to provide a full-fledged second floor with spacious rooms, and with enhanced insulation they can be used at any time of the year.

The main components of the gable roofing system

Now let's look at the basic structural elements of the gable roof system

. The scheme well underlines the main elements of the gable roof

• Mauerlat is a bar laid and fixed to the bearing long walls of the house. This element of the design is designed to distribute the load on the walls, which gives the rafter system, which helps protect the structure from deformation and destruction.

Mauerlat is laid on walls for even distribution of load on them.

The Mauerlatt bar must be made of wood resistant to moisture and damage by harmful insects, as well as having a certain strength. It can be larch( optimally) or pine - they are considered the most popular breeds for erecting the roofing system. The cross-section of the beam can be 120 × 120,150 × 150 mm or more - this size varies depending on the size of the roof structure and the thickness of the walls.

Rafting legs - the main supporting parts of the entire

• system The rafter is the main supporting element of the system that forms the roof slopes. Rafters are made from a beam, board or log, and the size of the material depends on the design parameters of the rafter system, the distance between the rafters, the weight of the roofing and the level of external loads.

Lapps serve to lengthen the rafters in the formation of the cornice overhang

• - this element is not necessarily present in the rafter system, but it is necessary when the rafter has insufficient length to form the eaves of the roof. When building a rafter leg, the filly is mounted on it by an overlap of 450 ÷ 500 mm.

Connection of rafter legs and run in the ridge area

• The is the top of the roof, and the top edges of the rafters are fixed, fixed to each other and to the ridge run. For example, the illustration shows the fastening of rafters on the ridge board, but in addition, this part of the system can be formed in other ways:

Several tricks of fastening the rafter on the ridge

a) the rafters are fastened together by means of wooden or metal overlays cut out in the form of a ridge angle and fixed on both sides of the connected rafters;

b) rafters are fixed on a ridge board installed on the edge;

c) in this case the rafters are fixed to the ridge board and additionally fixed from both sides by wooden or metal overlays.

A few more ways to connect the rafters and the ridge run

This illustration shows the connection of two rafters installed in an overlap and fastened together with screws or bolts. Another option is to join the rafters on a ridge run at an angle with further reinforcement of the joint on both sides with wood or metal overlays.

Composite ridge run from two parallel boards

• The ridge run is the connecting element for the rafter legs. It can consist of one board, a bar or two boards.

Run, jammed between the overlays.

The run is mounted on the racks fixed to the left, which is located at the bottom of the system and runs parallel to the ridge. In addition, it can be fixed between two overlays, fastening the rafters at the top.

In the attic, and sometimes in a simple gable system, side girders are installed, which serve to form a two-tiered arrangement of rafters in the attic or to impart stiffness to the ramps in a simple design.

On roofs of a large area the rafter system is reinforced with vertical struts

• Racks - are retaining vertical elements of the rafter system, made of timber and installed in different places, depending on the size and layout of the attic. They are fixed from below to the beams of the attic floor, which are the frame for the floor of the attic and the ceiling of the premises of the house, or on the beams:

- in the middle part of the rafter system - in this case the upper edge of the pillars supports the roof ridge;

- under the rafters, along the side edges of the attic.

Racks make the construction more rigid and reliable, and also help to relieve the load from the walls of the building.

These system parts can also become an element of the frame for an attic partition or for securing the lath under the roofing of the walls of the attic space.

Tighteners make the construction of rafters more reliable

• Tightening( bolt) - this element is installed between two rafters, as if pulling them together. Tightening can be mounted in the lower part of the rafters, closing the triangle of the truss and simultaneously acting as an attic floor beam, or in the upper part of the truss, and at the same time becomes the base for the roofing for the installation of the ceiling casing. On the end sides of the roof, the bolt is sometimes installed in the middle part of the triangle.

This element helps remove the load that the roof gives to the walls of the building. Especially it is necessary in the hanging rafter system, which will be discussed below.

With long rafter feet, the silt should be reinforced from the bottom with struts.

• The struts are support elements that reinforce the construction, which are usually installed at an angle of 45 degrees. They are mounted to avoid bending of the rafter legs, which are possible in strong winds or snow loads. The struts can be installed in the rafter system not only on the central pillar, but also on the side rails. Especially they are important for roofs of houses, erected in regions with snowy winters and strong winds.

The bottom is parallel to the ridge and supports the racks or struts

• The is an element that serves as a support for the central and side racks and for securing the struts.

Lathing - the basis for fixing the roofing material

• The lath is fixed to the rafters perpendicular to them and is designed to fix the roofing material on it. The step of its installation is calculated depending on the type of coating, so the crate can be rare, frequent and continuous. For our case, o is for metal shingles it is calculated depending on the transverse wave of the sheet.

Dimensional scheme of the roofing for the metal tile( parameters are shown in the table below)

Types of the gable roof systems

The gable roofing system can be hung andstitched rafters. Both one and the other scheme can be applied to the arrangement of the roof of metal roofing. To know what they differ from each other, and from which elements are composed, it is worthwhile to consider each of them. Here it should be noted that in the below diagrams only the main elements of the rafter systems are indicated, but if necessary they can be reinforced with additional details, as discussed above.

roof trussing system The ridge type roofing system is supported by the internal wall of the building

The roof truss system consists of the following main elements:

1 - Bearing walls.

2 - Mauerlat.

3 - Stand, installed on the left.

4 - Rafters.

5 - Lathing.

The damper system differs from the hanging system in that it is installed on a structure with internal capital partitions. The capital internal walls are used to secure the foot on which the racks supporting the ridge run are attached, with which the upper ends of the rafter legs are fastened. Then the rafters fix the boards of the crate.

This design is more popular than hanging, because it is reliable and easy to install.

Hanging rafter system

Hanging rafters rest only on the side walls of the building and are connected to the skate

The hanging rafter system scheme looks as shown in the illustration and includes the following main elements:

1 - Bearing walls.

2 - Mauerlat.

3 - Rafters.

4 - The lining.

5 - Tightening( bolt).

The suspension system of the rafters is mounted on two external bearing walls, on which the Mauerlat is pre-attached. This version of the roof can be used only if the distance between the bearing walls is not more than 7000 mm, because in addition there is no additional support for the roof truss structure. Such a system is usually equipped with puffs supported by slopes - these elements will remove some of the load from the walls of the building.

In addition to layering and suspension systems, there are combined options that include individual elements of the one and the other design.

When the rafter system is selected, it is recommended to make a detailed roof drawing with the dimensions before purchasing materials, so it will be easier to calculate the amount of all necessary and the amount for their purchase. In addition, such a scheme will greatly help to perform the installation work. But in order to draw a drawing, you will have to make some calculations.

How to calculate the parameters of the gable roof system

It is very important to correctly calculate the parameters of elements for installation work. To do this, it is recommended first to make a list of all the necessary ones and to perform a step-by-step calculation. All calculations should be made with a margin of 10-15%, avoiding unnecessary savings, which will be detrimental to the quality and strength of the structure.

If it is decided to perform this part of the work independently, it is necessary to check with technical documents developed by specialists, for example, placed in SNiP.

The main directions of the calculation will be three interrelated values ​​- the steepness of the slope, the height of the ridge over the overlap and the length of the rafter legs. Further, having linear parameters, it will be necessary to determine the cross section of the material for the rafters. But it already, in turn, depends on the loads exerted on the rafter system.

Loads on the truss system

The load on the truss system is divided into three categories:

• Constant loads. This category includes those that will constantly keep in tension the rafter system - the weight of the crate, the insulation, if it is provided, the roofing, windproof, hydro and vapor barrier film, fasteners, finishing materials for the interior of the attic. The weight of all the elements and materials necessary for the roofing "pie" is summarized, and on average the optimal value should be 40-45 kg / m².It is desirable to calculate materials in such a way that the weight of 1 m² does not exceed 50 kg / m², especially if a roof system with suspended rafters is used.
• Short-time loads. Such loads arise periodically and can have different effects on the structure. These include such impacts:

- snow and wind load;

- weight of people during repair work;

- climatic temperature effects;

- possible loads from ice.

These external loads lie in great dependence on the characteristics of the region of construction. In addition, their magnitude directly depends on the steepness of the rays. So, for example, on the gentle slopes the snow load will play a decisive role. With the increase in the steepness of the roof, the effect of snow pressure decreases, but the dependence on the wind effect increases. On slopes with a steepness of over 60 degrees, the snow load is written off altogether, but the sail surface of the roof increases many times, and the wind becomes the dominant external influence.

The snow load on the roof of

was clearly underestimated in the calculations. The data for calculations can be found in SNiP 2.01.07-85 * "Loads and effects" in the sections "Snow loads" and "Wind loads".At the same time, it is necessary to take into account not only the region of the location of the house, but also the place of its construction - a lowland or a hill, a separate building or surrounded by other buildings.

A convenient algorithm for calculating loads will be given below.

• Special loads. This category includes such factors as seismic impacts, hurricane wind, deformation processes due to subsidence of the ground, which are usually called force majeure circumstances. It is impossible to foresee everything, and in order for the roof to withstand all these tests, it is recommended to lay an additional margin of safety when acquiring materials and installing the structure.

If the roof is to be installed on an old building, it is necessary to calculate the load-bearing capacity of the foundation and walls, since the new roof can have more weight than the old one. Such calculations can be carried out professionally only by specialists, but it is necessary to make such calculations without fail, otherwise it will be necessary not only to change the roof, but also to repair the entire structure. Specialists will need to provide a roof project, in which all its parameters will be indicated.

Slope angle of rafters rails and skate heights

The angle of the location of the roof slopes is determined by the choice of the roofing material, since each of them requires a personal calculation. Often the manufacturer of a particular coating brand gives the necessary recommendations, but if we talk about general requirements, for example, for our case - metal tiles, then for it the angle of slope should be at least 20 degrees.

Dependence of attic room dimensions from the corners of the ramp

Increasing the angle of the slope will significantly expand the attic space, but for the construction of such a roof will require more building materials and, of course, the construction cost will increase significantly.

So, any gable roof system, whether symmetrical or not, can be represented as a triangle.

Drawing that will help us in the calculation of

Its vertices:

- point "a" is the outer point of intersection of the rafter with the Mauerlate. This corner is adjoined by an angle "A", which determines the steepness of the roof slope.

- point " b" - the top of the ridge.

- point "with" - intersection of a steep line from a skate with overlapping ildi just the upper level of the wall.

The known reference value is " D" the length of the base of the triangle. For a symmetrical roof - this is half the span. For asymmetric options - it can be different, it's easy to determine.

"H" - the height of the ridge above the base( overlap);

" L" is the length of the rafter leg, which can be increased by "m" if desired, to form a curtain overhang.

According to the known trigonometric relations:

H = D × tgA

Thus, it is possible either to determine the height of the ridge from the specified angle A, or, on the contrary, determining the height of the attic beforehand, determine the steepness of the ramp.

All this makes it easy to make the calculator below. By changing the value of the angle " A" it is possible to come to the optimum height " H" .

Calculator for calculating the height of the ridge

The length of the rafters

To calculate the length of the rafter feetfor a particular roof system, it is easiest to use the Pythagorean theorem. The two sides of the right triangle( the legs " D" and " H") are already known, and it remains to find only the hypotenuse " L" , that is, in fact, the length of the rafters.

L = √( D ² + H²)

You can immediately add the "makeweight" "m" if desired, to create a curtain overhang.

All this allows you to quickly and accurately calculate the calculator below.

calculator calculating rafter length

Here it is necessary to make an update. As a rule, the biggest length of a standard bar is 6000 mm, so for a curtain overhang, it may be necessary to extend it to the desired size with a "mare".

Example of splicing

If the overhang is only expanded, the rafters and "filly" can be spliced ​​in different ways - twisting through two overlays installed on both sides of the joint, diagonal, toothed, stepped and other connection methods. It is necessary to know that the more the segment to be joined, the greater overlap should be provided.

Laths for the formation of the eaves

Calculation of the step and section of the rafters

Now, when it became clear how to calculate the length of the rafter, you need to figure out which section should have the rafters, and also at what distance from each other to install them.

The rafters are installed with a certain pitch, and the smaller it is, the lower the distributed load

. Here it is necessary to calculate the load on the entire truss system, per square meter of the area, and from it - distributed, per running meter of the rafter.

The distributed load will be the lower, the more often the rafters are installed. Hence, "playing" with the obtained values ​​and the step of installing the rafters, you can find the best option, providing an acceptable load( in any case it should not exceed 175 kg per running meter).

This value will allow you to enter the table in order to already determine it with the required section of rafters

. To calculate the distributed load, a convenient calculator is placed below. He will take into account the roofing system of the roofing system, and the external load( wind and snow).And the angle of the roof slope.

Calculator for calculating the distributed load on the rafter

The first step on the attached maps is to determine the regions of your region in terms of snow and wind load.

Zoning of the territory of Russia for the level of snow load

Zoning of the territory of Russia according to the degree of wind pressure

Next, we will have to assess the degree of closure of the construction site. In this case, take into account that artificial or natural obstacles to the wind should be no more than in a radius of 30 × h, where h is the height of the house along the ridge. For example, for a five-meter house, a circle with a radius of 150 meters is taken into account.

The step of installing the rafters is a variable in this case, and changing it, you can achieve optimal load distribution.

	The first step on the wall of the building is a waterproofing material. Usually, for this purpose, a roofing material is chosen, which is fixed to the mastic or simply laid "dry". Waterproofing is mounted only on brick or stone walls, it is not laid on wooden walls.
	Mauerlatt can be attached to the wall in two ways. In the first variant - on the threaded stud, embedded in reinforcing concrete, passing on the top of the wall belt. In this case, the waterproofing and mauerlat are put on top of it. To do this, holes are drilled in the bar with a diameter exceeding the diameter of the stud by 2 ÷ 2.5 mm.
	Another option - fastening is made by spacer anchor bolts. A hole of the required diameter is drilled under them - directly through the beam of the Mauerlat to the concrete belt of the strapping. After installation of the anchor tighten, which ensures reliable fixation of the Mauerlate on the wall.
	On top of the Mauerlat, after it is fixed, the ends of the studs or anchor bolts may stick out. To ensure that they do not interfere with the further installation of rafter legs, they are recommended to be cut using a grinder. The next step on the Mauerlate is marking, which will be the insertion of the rafter feet.
	On the rafters prepared along the length, cuts are made, which go deeper into the board for no more than ⅓ its width. With this cut, the rafter leg should be firmly attached to the outer edge of the Mauerlat.
	If it is supposed to make rigid fastening of rafter legs to the Mauerlat, then on the markings on the beam it is possible to fasten two metal corners between which will be fixed with the help of screws or a through bolt of rafters. However, the final fixing process should be carried out after the pair is connected in the ridge part.
	Instead of rigidly fixing corners to fix the rafters to the Mauerlat, a sliding fastening can be used that will keep the roof structure from deforming when shrinking the walls of the house, as the rafters will be able to shift, compensating for these fluctuations. This approach is most often used when the walls are a wooden frame that gives a strong shrinkage at first.
	The next step is the pair of rafters trying on, fitting and fastening in the ridge part in one of the ways described above. Their fastening can be made after installation on the Mauerlat or on the ground, and then lift and install in the intended place for them. It is usual to first mount the extreme pairs bordering on the pediments, and then pull a cord between them, which will denote the line for the rest of the rafters.
	After all the rafter pairs have been exposed and temporarily fixed on the mauerlat at the bottom, they must be rigidly fastened with a ridge run that is mounted under the connected rafters. Each of the rafter legs( pairs) is fixed to the run on both sides with metal corners.
	After achieving the necessary rigidity of the upper part of the system, the rafter legs are firmly fixed to the Mauerlat. Then, in the lower part of the structure for each of the rafters installed tightening. After that, they determine the middle, to which will be fixed the rack, propping the skate. On both sides of the rack are fixed struts - they will also give these kind of trusses the necessary strength and stability.
	The trussed truss assemblies can also be manufactured on the ground, and then raised to the height and installed according to the markings. But in this case alone can not cope with the work, so several assistants will be needed. Finished farms must have sufficient rigidity so that when they are raised on the walls they do not deform. Therefore, they are reliably strengthened by posts, a grandmother and slopes. Each of the farms after the elevation to the height is exposed and temporarily fixed to the Mauerlat with a support board. After linking trusses with longitudinal passes, these supports can be removed.
	The next step rafters are lengthened with fillets, which form the overhang( unless, of course, the cornice overhang was previously laid in the length of the rafter's legs).
	The waterproofing membrane is then laid on the rafter system. If it is purchased in a roll version, then its flooring starts from the eaves, longitudinal horizontal strips. Each subsequent upper web is laid on the lower one with overlap of 100 ÷ 150 mm. The material is fixed to the rafters using a stapler and staples. If a diffuse diaphragm is used, it is necessary to monitor the correctness of its position - the side marked must face the street. On the top of the waterproofing, also to the rafter feet, the screws of the counterbrush are screwed onto the screws, which press the membrane, and also set the necessary vent clearance above it.
	The next step is to design the roof overhang. For this purpose, the windboard is fixed to the end faces of the rafters. On top of it, on the rafters and the grill, the first rails of the crate are mounted.
	On the first board of the battens, at a distance of 1000 mm from each other, or under it, the rafter legs are immediately fixed with holders for the gutter chute. Then, on the first board of the battens it is recommended to install a windbreak metal bar that will protect the wood from moisture entering it.
	Then, on the wall, the line on which the bar is fixed is repulsed. On it and on the bottom end of the wind board the cladding material is fixed. At the same time, do not forget to leave clearances for ventilation or build in perforated soffits.
	Next on the grill, the boards of the crate are fixed. In circuits, the distance between the centers of adjacent planks is usually placed. Here it is necessary to pay attention to the fact that the distance between the cornice board of the crate and the subsequent is somewhat smaller( by 25-30%) than between those that are fixed above. For ease of operation, it is possible to produce calibration rails of the required length, taking into account the step and the width of the board of the crate - so it will go much faster. Reiki fit on the rafter legs on both sides of the board of the crate, the board is installed by it - and you can immediately begin fixing it with screws( nails).
	The next step is laying and fixing the metal tiles. Operation can be carried out in two ways, depending on the size of the sheets of material. If the sheets have a small height and must be laid in several rows, then they are erected from the eaves. First, overlap one wave and fix the sheets of the first row. Then overlapped to the set width, depending on the tile relief, the second row of material is mounted on the bottom row of sheets. Moreover, the installation of each row is made from the same side of the ramp. So all the rows of metal tiles are installed up to the ridge. It should be taken into account that a gap must be formed on the ridge between two covered ramps with a size of 50 ÷ 70 mm - it is necessary for ventilation of the roof pie.
	If sheets of metal tiles cover the ramp along the entire length from the ridge to the cornice overhang, then the installation will be much easier. The first sheet of material is stacked and aligned along the edge of the ramp, then secured. The next sheet is overlapped first on one wave - and so the rest of the coating is installed. In this case, a gap is also left on the ridge for ventilation.
	From the front side of the ramps, upon completion of the installation of the metal tile, the windings are fixed. They overlap the roofing material by 100 ÷ 120 mm.
	The final stage of the work is the installation of a ridge element, on the inner edges of which an air-tight seal is fixed. Other ridge elements may be used, but the main thing is to ensure free ventilation of the under-roof space.
	The fastening of all metal elements on the crate is carried out with the help of special screws having a rubber sealing ring under the press disc. Similar self-tapping screws with a hexagonal head for 10 are produced in different colors, so it will not be difficult to choose them for the chosen shade of metal tiles.
	After the roofing material is fixed, you can, without fear of rain and without hurrying, go to the installation of insulation material. Often, mineral wool is used for the attic space, best of all - basalt, as the least hygroscopic. Mats are laid between the rafters, and the thickness of the insulation must be the same size as the height of the beam of rafter legs, or 5 ÷ 8 mm less. If necessary( based on the results of calculations), two-layer insulation can be used. In this case, after laying the first layer of thermal insulation, a lath is installed perpendicular to the rafters, between which the second layer is already laid.
	Over the insulation, fix the vapor barrier membrane, beginning from the floor and gradually rising upwards. If the vapor barrier material is purchased in rolls, then it is overlapped by 150 ÷ ​​200 mm. All joints are compulsorily sealed with special waterproof tape, so as not to leave loopholes to penetrate the moisture from the inside.
	Next, the vapor barrier is fixed by the rails, which are fixed to the rafters. On these counter-rails, then the lining of the attic space is installed - it can be plastic or wooden lining, sheets of plasterboard or plywood( OSB). If it is planned to mount the skin material vertically, then a horizontal crate is installed on top of the already secured counter-rails. In a word, the curtain rails must be perpendicular to the direction of the finishing material - different options are possible, depending on the number of layers of insulation material and the final orientation of the guide elements. But in any case a gap of at least 10 ÷ 15 mm is left between the vapor barrier film and the trim.
Illustration	Brief description of the operation

With the obtained value go to the table. How to use it - is clearly shown by arrows.

The table of sawn sections for rafters and the principle of using it

The example shows that for a load of 75 kg / m and a rafter length of 5 m, the sawn timber is suitable for the section shown in this row to the left.

Parameters of other sawn timber

Some wooden structural elements are calculated according to the thickness of the rafters, for example ridge run, as the rafters must be securely fastened on it. The rest of the parts are usually made of the following bars and boards:

• Mauerlat - beam from 120 × 120 to 150 × 150 mm or more.
• The tightening is usually performed from a board section of 30 × 150 to 45 × 150 mm.
• Racks and struts - from a bar section 100 × 100, and sometimes even 120 × 120 mm.
• Led. Its cross-section must be equal to the section of the post, since it will be fixed to it.
• The thickness of the board for the crate varies from 20 × 100 to 25 × 150 mm - this parameter will depend on the weight and other features of the roofing material.

Sequence of installation of the roofing system for metal roofing and roofing

If the roofing system is to be installed on a newly erected house and the floor has not yet been laid on the floor slabs, then, for the convenience and safety of their execution, a temporary flooring of the boards must be arranged before the work starts.

The sequence of installation of the rafter system under the metal tile may differ somewhat, but always consists of the following main steps.

Summarizing the publication, it can be summarized that erecting the truss system is a very difficult process, both in calculations and in practical installation. Therefore, with the slightest doubt in its own capabilities, it is best to entrust it to specialists with extensive experience in this work. Only in this case will the roof be solid and reliable.

In conclusion - an interesting video about the installation of a gable roof system under the metal.

Video: construction of a gable roof structure for metal roofing