- Necessary material
- The industrial structure, a structure adapted to all buildings
- Make a precise plan before laying
- To care for the reinforcements of the pieces of wood
- The farms
- Setting up the farmhouses
- Installation of the vault
- Realization of roof connections
In vogue since the end of the 1960s, the industrial framework developed strongly in France. Made in the factory with wood of small sections, this type of roof frame is quick and easy to install for an affordable price.
- Carpenter's hammer
- Chain saw
- Nail gun
- Lifting equipment
- Industrial huts in pine
- Douglas planks (3000 x 200 x 27 mm)
- Chevrons (60 x 80 mm)
- Wood cleats (various sections)
- Concrete iron (Ø 10)
- Lime mortar
- Miscellaneous nail shop
Cost: 48 € TTC / m² of roof (except roof and cover)
Time: 10 days (to 2 people)
The industrial framing is based on the pose of repetitive elements called "farms". These are placed directly on the chaining or floor of the building to be covered. And allow to replace rafters and classic failures with the direct laying of the cover battens.
The industrial structure, a structure adapted to all buildings
This 18th century barne century saw its roof deteriorate over time, some of the masonry carrier is damaged. After the removal of the old blanket completed with metal sheets to limit leaks, the bearing walls had to be consolidated, before being belted on the periphery in the upper part with reinforced concrete. A trick to find a solid and flat surface before laying the farmhouses.
The L-shaped barn implies a change of direction in the setting of the farmhouses and the creation of hips. Another peculiarity of the roof lies in its junction with a perpendicular annex building, which has a traditional farm. To respect the original architecture of the barn, false rafters are attached to the beams to create eaves on the front and rear facades, with the exception of the gables whose roof is flush with the exposed stone.
Make a precise plan before laying
Finally, to establish all these elements, a detailed laying plan has been drawn up with, as a basis, a installation distance of 60 cm. Unless you are competent in the field, it is recommended to entrust the realization of your plan to a design office.
Crossbowman entering a punch... a farmhouse consists of several pieces of wood constituting a frame resistant to the load of the cover. Each piece is linked by galvanized steel tooth connectorsor even inox for wetlands. The latter are stamped and pressed in the factory, just to form a flat structure, light, resistant and dimensionally stable. The connection of the trusses between them is provided by the anti-buckling and bracing devices to ensure the stability and rigidity of the assembly.
Triangular, curved, scissors, various forms exist. Some are specific: truncated, half-trusses... This technology adapts to all forms of frames and all buildings.
Finally, sidewallsx in front as in pinion to respect the architectural codes are possible: right overhang, in coyau, in tail of cow...
The industrial farmhouse is appreciated not only in the construction of new houses, but also in renovation because of its speed of execution and its advantageous price.
To care for the reinforcements of the pieces of wood
Industrial structures use penthouses with little transversal rigidity. Also, when all are in place, it is important to stiffen the assembly to prevent the pieces of wood from deforming by buckling. And to violate all the farms to secure them.
The antiflux device avoids the deformation of the elements of the farms, compressed by the weight of the cover and the ceiling. The rafters, which undergo great axial compressive forces due to their small thickness, will deform laterally. The battens alone can not provide the role of antiflambage. Also, we use pieces of wood arranged perpendicular to the beams and crossbowmen.
Placed perpendicular to the farmhouses, the bracing stabilizes the frame against the effects of wind. The elements are made by wooden rails. The parts used will make triangular assemblies with the farmhouses, and therefore undeformable.
The elements composing a farm
The assembly of the fermettes is carried out to obtain the intersection at the same point of the axes of each piece of wood. These "canonical nodes" are the places of intersection of the neutral fibers of the resumption of efforts.
- Spacer for slope farmhouse> 35%
Farmhouse modelsThe choice of a farmhouse model depends on the use of the attic to create. The presence of cards and struts excludes de facto development possibilities. In addition to the simplicity of its implementation, the farmhouse is interesting price side. Count about 60 euros of m².
|In A or in rolled up|
|In wide chisel|
|In tight chisel|
The different types of reinforcement of an industrial structure
- AT. Antiflangement under crossbowmen
To connect the ridge to the chaining and stabilize the gables (indicated in red).
- B. braces
To keep the farms in the wind.
- C. Sliding rails under a rafter
To guarantee the parallelism of the rafters.
- D. Smooth sliders on tie
To maintain the spacing of the trusses and avoid transverse deformations.
The junction of two buildings imposes farms of varying sizes and the creation of a valley. The ties are placed on the flight previously nailed to the farmhouse and held by a cleat to prevent slippage. The devices of antiflambement and bracing are made as on a current roof.
Setting up the farmhouses
- Fit small farmhouses on the masonry wall of the load bearing walls.
- With chalk, check the ridge line after placing each of them at a distance of 60 cm.
- Temporarily nail a piece of wood to keep in place the first farmhouses installed.
- Fix the ties in the masonry belt with brackets and lag bolts.
- Fix the anti-buckling and bracing wood devices, scrupulously respecting the execution plan.
- Then, remove the temporary holding pins.
- Lay sections of rafters at regular intervals against the trusses to create an eave.
- Arrange a registration line before their beveled cut at the end.
- Between the rafters, complete the masonry with stones sealed with lime mortar in order to close the bottom of the roof and to avoid the intrusion of rodents and birds.
- Once all spaces between rafters filled with mortar, smooth them without waiting to the metal ruler following the slope for the installation of the first flight.
- Following the same principle, close the top of the gables with mortar by installing sections of twisted concrete reinforcing bars to reinforce the structural base (chaining).
- Again, smooth down the slope.
After a precise survey, the installation plan prepared beforehand for implementation allows to draw up the detailed quantity of supplies. But also to adjust his order of materials without excess or lack.
Installation of the vault
- Dry mortar, start fixing of the planks of poultry in the farmhouses on the false rafters using a nail gun.
- Cross the joints one rank out of two.
- At the end of the roof, cut the trenches that extend beyond chainsaw hips following the slope of the roof.
- Continue with the same method.
- As the façade wall is not rectilinear, draw on the planks placed against the masonry a cut line to the metal ruler.
- Then, cut the flutes following the layout to start again.
- Continue to the ridge.
- Mark the location of the last flights before nailing.
- Then, cut in the length the last row of plumes.
Realization of roof connections
- At the junction of the roofs of the two buildings, install each farm element specifically annotated and marked on the laying plane.
- Align the ridge line as before.
- To do this, he had to rest on a roof of the contiguous roof held by a rod nailed against its base.
- To join the two inverted roof panels, it is necessary to lay sections of trusses of varying heights on the slope to create two valleys that will ensure a good flow of water.
- The trusses are set in foot on chocks.
- Lay the panes of this pan.
- Halfway through the roof, start, again with the chainsaw, to cut the overhangs following the slope.
- Cover the trench with a rainscreen before installing the slates (20 x 40 cm class A), zinc fittings and chénaux.