FR2585749A1 - Timber truss for houses with habitable roof spaces - Google Patents

Abstract

The invention relates to a timber truss for houses with habitable roof spaces. The subject of the invention is a timber truss for a house with habitable roof spaces, of the two-level type and consisting of trusses with trestles having broken rafters, characterised in that the said trestles 15 support purlins 4 made by tie beams 5 and themselves supporting the principal rafters 7 of the upper level of the truss, particle or plywood boards 6, 11 being nailed to the said tie beams 5, as well as to the external face of the principal rafters 2, 7 of the two levels of the truss. Application to houses with habitable roof spaces.

Description

WOOD FRAME FOR HOUSES WITH CONVERTIBLE ROOFS
The present invention relates to a new technique for constructing wooden frames for houses with convertible attics.

 The usual techniques for making convertible attics use traditional frames or trusses.

Traditional frames have the following disadvantages
- annoying farms for attic development
- heavy pieces of wood requiring lifting means
mechanical
- poor load distribution on the masonry;
- risk of workers falling
- need for skilled labor
- system badly suited to mass prefabrication.

Furthermore, frame trusses also have various drawbacks.
- large and heavy elements, difficult to understand;
- in the case of attic development: frame not visible
te and not accessible
- roof space lost in the lower part and in the upper part
- construction system poorly suited to four-person roofs
slopes with attic space
- to each width of house corresponds a dimension
different farmhouses, hence difficulty in standardizing
station.

 In the last type of construction, industrialized two-part farmhouses have been produced for a few years which, after assembly, form trusses with interrupted rafters, but these structures are not yet fully satisfactory, in particular in terms of rigidity and stability, in terms of ease and simplification of the attic layout, and in terms of the simplicity of assembly and standardization of the various elements of the frame.

 The object of the invention is precisely to propose an improved technique for making trusses with interrupted rafters for two-level frames for houses with convertible attics.

 To this end, the invention relates to a wooden frame for house with convertible attic, of the type on two levels and consisting of trestle trestles with interrupted crossbowmen, characterized in that said easels support purlins connected by ties and supporting themselves' the rafters of the upper level of the frame, particle board or plywood being nailed on said beams, as well as on the outer face of the rafters of the two levels of the frame.

 Such a frame makes it possible to make the roof in two stages by building the first level of frame in the form, for a gable roof, of a pyramid trunk constituting, thanks to the rafters, ties and panels, a rigid and non-deformable shell. , then, construction of the second level from the first, also in the form of a rigid and non-deformable shell with four sides thanks to the rafters and panels of this level.

 This frame leaves completely free the interior space on each level and completely visible the elements of the frame.

 According to another characteristic of this frame, said trestles are provided with stirrups and a peripheral sole for distributing the loads on the floor.

 According to another characteristic, said easels comprise, substantially at mid-height of the struts, a peripheral shelf covered with a carpet or the like falling freely between the legs and serving as a closure for storage volumes inside which are arranged. pipes, especially those sensitive to cold.

 According to yet another characteristic of the frame, in the case of a four-slope roof, the hip joints are formed by two pieces of the same section as the rafters, joined by their lower edge and each arranged in the same plane as the corresponding rafters, which facilitates the nailing of ceilings.

Other characteristics and advantages will emerge from the following description of embodiments of frames according to the invention, description given by way of example only and with reference to the attached drawings in which
- Figure 1 shows a cross section of a
frame according to the invention
- Figure 2 shows a longitudinal section of
frame in the case of a gable roof;
- Figure 3 shows an enlarged partial view of
the lower part of the frame and overhangs
of the roof
- Figure 4 shows a variant of the overhang of the
roofing
- Figure 5 shows a top view of the first
level of a frame with four slopes at various
assembly steps, and
- Figure 6 shows a top view of the second
level of this framework at various stages of the
mounting.

 The frame shown in Figure 1 consists of footings 1 supporting rafters 2 and struts 3. The trestles thus formed support purlins 4 connected by ties 5 on which is nailed a floor 6 in particle board or plywood or the like.

 On this floor are nailed rafters 7 connected by ties 8. Incidentally, along the width of the attic floor, soles 9 and struts 10 can be arranged as reinforcement.

 On the entire frame (rafters 2 and 7) are nailed particle board or plywood or the like 11; they have a triple utility: reinforcement of the frame, ready-to-paint or upholstered ceilings, thermal insulation support 12.

 In the case of a four-slope roof (Figure 2) the rump trestles support purlins 16 which themselves connect the purlins of long sections 4.

 The rump trestles and long sides 15 are connected by struts 18 and 19 and. By a peripheral sole 17 which distributes the loads on the floor and serves as a plinth. Halfway up the struts 3 rests a peripheral shelf 20 made of particle board or the like.

The shelf is covered with a carpet 21 which falls freely between the legs 3, thus serving as a closure to the rahgement volumes 22 inside which can be arranged pipes 23, in particular cold-sensitive pipes which are thus frost-free.

 The entire volume of the frame is insulated by insulating panels 12 held by slats 24 fixed to the rafters 2 by nails or screws 25. On these slats are nailed the battens supporting the cover 26.

In order to extend the roof externally, and depending on the type of finish desired, there are cores 27 fixed on the flanges 1 and the slats 24
The cores 27 ′ (FIG. 4) can extend beyond the soles 1 ′ according to the so-called "cow-tail" arrangement.

 The trestles 15 are fixed to the floor at intervals which are preferably regular, but which can be modified, for example in line with the dormer windows. The ties 5 support the attic floor. They are preferably placed at the right of the easels but can be removed for the passage of a flue or staircase.

 Such an arrangement is particular to the present invention. Indeed, the current interrupted crossbowman farms do not allow this freedom of spacing of the trestles 15 and the ties 5 because the two parts of the crossbowmen are usually molded and the ties are supported directly on the rafters.

 In the present invention the interposition of breakdowns 4.16 between, on the one hand, the trestles 15 and, on the other hand, the struts 5 and the rafters 7 of the upper level, ensures such freedom.

 The hips 28 (FIGS. 5,6) preferably consist of two pieces of wood of the same section as the rafters 7, joined by their lower edge and each arranged in the same plane as the corresponding rafters.

This arrangement facilitates the nailing of the ceilings 11.

 On the thirds 28 are fixed hip bridges 29 similar to the easels 15 but whose chevron is shortened by a bias cut performed in the factory.

 At the second level of the frame (FIG. 6) the rafters 7 are preferably arranged in line with the ties 5.

 In case of offset rafter / entered, small triangular wedges arranged between the purlins 4 and the floor 6 transmit the load of the rafters 7 to the purlins.

The sections and lengths of the constituent elements of such frames can be very reduced. For example for all house widths less than 9 m
- section 8x10 in 3 lengths: 300,400,500 for: porti
ques, hip rafters, braces, straps, stiffeners
sisters, struts, cores, spears
- 8x20 section in 2 lengths: 300,400 for: pe sole
device, breakdowns.

 Short elements such as struts, top braces, cores and braces have lengths which are submultiples of the lengths in stock.

 The implementation of the technique according to the invention therefore makes it possible to reduce stocks.

 Since sawmills are generally equipped with four-sided planers, it is advisable to store planed wood, which has the dual purpose of calibrating it perfectly and giving it a good appearance since the frames will remain visible.

 This technique is easily used in prefabrication. This consists of cutting the above-mentioned elements on templates or on automatic machines, then assembling the easels on templates.

 It can be carried out by unqualified personnel. With constant covering slopes, the different porticos are identical whatever the dimensions of the houses to be covered, hence a reduction in stocks of prefabricated elements which is not the case with industrialized frameworks in small farms. Furthermore, there is no handling of large elements.

The frames of the invention are assembled in the following order
- easels with long sides, rump easels, sole
peripheral,
- breakdowns, struts,
- hip, hip easels,
- braces,
- attic floor, first level ceilings,
- second level rafters, ties, soles, legs
by force,
- hips, span,
- second level ceilings,
- insulating panels held by the slats,
- cores,
- battens, blanket,
- peripheral shelf.

The advantages of the frame according to the invention stem mainly from the marriage of two techniques which gives it its novelty character
A> Non-deformable shell construction presenting the
following features and benefits
- particle board or plywood constituting
sloped ceilings and attic floor, nailed
on rafters and beams, provide rigidity and
non-deformability to the frame, hence removal of
trusses, part of the purlins, and bracing;
- these deletions allow
wood saving
elimination of heavy handling
total release of the volume of the floor (ease of composition of the layout plan)
. recovery of the upper volume allowing
swim an attic
uniform load distribution
- the entirely visible framework of the interior ensures:
. aesthetic
. total accessibility, hence ease of treatment
subsequent (insecticide treatments with a
time-limited action);
- recovery of the lateral roof space, generally unnecessary
sands, by a peripheral shelf forming boxes
inside which are hidden the
various pipes which thus remain accessible and
frost shelter
continuous exterior insulation prevents loss of
heat
- simplification of interior fittings.

B) Construction in two statically independent levels
with the following features and advantages:
- wood of reduced sections and lengths
- standardization of all the structural elements of the
first level (except ties) whatever
the length and width of the houses to be covered
- total prefabrication in light elements, hence rapidity
assembly without lifting means and by labor
current
- assembly of the attic frame after laying the floor
attic, hence ease of movement for
workers and reduced risk of falling
- the slopes of each level can be different this
which improves the aesthetics of the roof.

 Finally, the invention is obviously not limited to the embodiments shown and described above but on the contrary covers all variants.

Claims (4)

RVENDTCATIONS  1. Wooden frame for house with convertible attic, of the two-level type and consisting of trestle trestles with interrupted crossbowers, characterized in that said easels (15) support purlins (4) connected by ties (5) and supporting themselves the rafters (7) of the upper level of the frame, panels (6,11) of particles or plywood being nailed on said beams (5), as well as on the external face of the rafters (2,7) two levels of the frame.  2. Frame according to claim 1, characterized in that said trestles (15) are provided with dtetresillons (18,19) and a peripheral sole (17) for distributing loads on the floor.  3. Framework according to claim 1 or 2, characterized in that said trestles (15) comprise, substantially at mid-height of the force jams (3), a peripheral shelf (20) covered with a carpet or the like (21) falling freely between the legs and serving as a closure for storage volumes (22) inside which the pipes (23) are arranged, in particular those sensitive to cold.  4. Frame according to one of claims 1 to 3, characterized in that in the case of a four-slope roof, the hips (28) are constituted by two pieces of the same section as the rafters, joined by their lower edge and arranged each in the same plane as the corresponding rafters (2,7,29).