Roofs of houses with a timber frame construction
Roofs are carried out скатными or flat. To roofs with a downgrade 1:6 and more, to flat - roofs with a downgrade less 1:6 concern. Flat roofs should have a downgrade not less 1:50 for maintenance of a drain rain and a melt water. In pitched roofs in space between a roof and horizontal flooring of an upper floor (attic flooring) the attic floor or a penthouse is arranged. Flat roofs are carried out .
The house roof consists of a wooden load-bearing framework to which fastens:
- From above - a solid roofing flooring or a purlin on which the roof providing necessary protection against penetration of an atmospheric precipitation and a melt water settles down;
- From below - ceiling filing over which the vapour barrier and a heater providing a necessary thermal protection settles down.
In houses in height 3 floors ceiling filing should be executed from sheets of type sheets of type ГВЛ in the thickness not less than 12,5 mm (under requirements of fire safety).
The structure of designs and flat roofs of the house includes the corbels providing partial tap of thawed with roof thawed and rain water from external walls, and into structure of designs of pitched roofs - if necessary, also face frontispices with corbels over them.
In designs of roofs it is necessary to provide the vent holes, allowing to deduce outside the damp air getting on an attic floor from heated premises.
For a fastening of elements of a framing of roofs the fixing parts which have been not provided in the present section (for example, plates) can be used. In this case durability of connections should be not less provided in the provided ways that should be confirmed by calculations or to trials
In pitched roofs the load-bearing framework consists of girders of attic flooring, rafters, and also коньковых boards or girders and, at necessity, intermediate bearers of rafters. The bottom ends of rafters lean against a framing of exterior load bearing walls, and top can incorporate among themselves through a board without vertical bearers or with on a girder which in turn leans against the racks transferring loading on an internal load bearing wall or on lintel. As intermediate bearers of rafters can be used: beam ties; penthouse walls; the racks transferring loading on a framing of attic flooring; the compressed inclined braces
Possibility of application of wooden roof frames of factory manufacturing or collected on the earth is provided also.
Load-bearing framework of flat roofs are the roofing girders combining functions of rafters and girders of attic flooring. Sectional views, spans and steps of elements of a load-bearing framework of a roof should pay off on depending on the accepted design load on them, defined according to requirements
For roofs at width of the house no more and a step of wooden load-carrying structures of a framing (rafters, girders), not exceeding 600 mm, sectional views of elements of a framing it is supposed to accept than 9,8 m without calculation depending on their span.
If loading is transferred to girders of attic flooring through racks from rafters height of sectional view of such girders should exceed not less than on 25 mm height. In houses in height 3 floors the width of sectional view of open rafters, roofing girders and lintels бесчердачных coatings under requirements of fire safety should be not less than 89 mm.
The floor beams bearing a ceiling from wood fibreboards, for prevention of twisting along beads of the bottom side should be fixed by the device of a purlin or vertical diagonal communications.
In cases, when it is required, that the roof has sustained the additional uniformly distributed loading created by heavy roofing materials (such as a concrete roofing slab), possibility of perception of this additional loading should be checked by calculation.
Diagonal rafters on ridges and under ендовами roofs should be executed from the converted timber which height of sectional view is more than height of sectional view of ordinary rafters not less than on 50 mm at width of sectional view not less than 38 mm.
In cases of use of integral rafters on length, roofing girders and girders of attic flooring joints of elements making them should settle down over vertical bearers.
Rafters, roofing girders, and also girders of attic flooring should be doubled on each party of apertures in a roof or the attic flooring, exceeding on width distance between two rafters or girders.
Elements of a framing of a roof should be made of a pine wood not below 2nd grade in accordance with GOST 8486.
Load-bearing framework of a pitched roof with a downgrade 1:3 and more, collected on site
In pitched roofs with a downgrade 1:3 and more vertical bearer for the top ends of rafters under the fad usually is not arranged. Horizontal распор rafters in these cases it is perceived by girders of attic flooring which simultaneously are string pieces.
Rafters of opposite slopes should settle down directly against each other and to incorporate the top ends through a board in the thickness not less than 19 mm end-to-end or when girders of attic flooring are made of the elements connected among themselves , - to displacement for own thickness.
Rafters and girders of attic flooring should lean directly against wood structures of external walls.
On basic lots it is necessary for rafters to give the certain form to provide equal platforms опирания.
Connections of the basic ends of rafters and girders of attic flooring, and also elements of girders of attic flooring among themselves, perceiving horizontal распор rafters, are carried out on nails. The ends of rafters and girders incorporate thus , the ends of elements of integral girders on length - внахлест or in a butt end to a battening plate from a bar of the same sectional view. Quantity of nails in each connection of rafters with girders depending on a roof downgrade. Used for reduction of spans and the sizes of sectional view of rafters intermediate bearers in the form of string pieces should be produced from converted timber by sectional view not less than 38'89 mm. String pieces in length more than 2,4 m should incorporate among themselves near to the middle not cutting elements (communications) by sectional view not less than 19'89 mm, located at right angles to string pieces.
Load-bearing framework of a pitched roof with a downgrade less 1:3, collected on site
In pitched roofs with a downgrade less 1:3 the top ends of rafters follows on a girder sectional view not less than 38'140 mm, stacked on vertical racks sectional view not less than 38'89 mm which are established on a stud of an internal load bearing wall with step of 1,2 m.
If necessary spans girders between supporting poles can be increased.
In roofs with a small downgrade for space formation between the top stud of walls and a roofing flooring stacked on rafters, sufficient for placing in it of a heater and a ventilated air interlaminar layer, the bottom basic ends of rafters follows опирать not on the top stud of walls, and on the basic board located above a stud sectional view not less than 38'89 mm. This board keeps within on girders of attic flooring and is nailed down to each girder. Rafters are nailed down to a basic board.
In cases when the certain lot of an external wall is displaced in the house under the general roof, girders of attic flooring supporting these wall keep within on a stud of a framing of an external wall.
The device of a framing of a pitched roof at the external wall displaced in the house
Under rafters on this lot of a wall the basic wall from vertical racks and the stud of the same sectional view laid on them, as an external wall framing is arranged. Racks are established on an external wall stud under each rafter. Rafters should lean against a stud of a basic wall and be attached to it by nails. An intermediate bearer in pitched roofs with a downgrade less 1:3 basic walls with the top both bottom stud and racks sectional view 38'89 mm which are established in plane with rafters and girders of attic flooring can be and are nailed up to them.
Intermediate bearers can be also the compressed inclined braces under rafters which are produced from converted timber by sectional view not less than 38'89 mm and are established from everyone стропилины to an internal load bearing wall at an angle not less than 45 ° to a horizontal.
Instead of the load-bearing framework of pitched roofs collected on site, the roof frames made industrially or collected preliminary on a building site can be applied.
Designing of roof frames, including butt joints of their elements, should be carried out according to requirements СНиП II-25.
Roof frames with the compressed elements of the lattice which length exceeds 1,8 m, should have cross-section system of communications in order to avoid a longitudinal bending down.
The system of communications to consist of boards sectional view not less than 19'89 mm which have been nailed down at right angles to elements of a lattice near to their middle a minimum by two nails in length of 60 mm for each element.
Elements of roof frames are not supposed to be kerfed, made an incision, bored through, causing their loosening if it is not provided in workshop drawings of elements of trusses.
Framing of a flat roof
The height of sectional view of roofing girders can be insufficient for placing in spaces between girders of a heater of a demanded thickness and ventilation space maintenance according to In such cases height of sectional view of roofing girders should be increased by necessary size.
Roofing girders fasten to a stud of load bearing walls two nails the in length of 80 mm вкосую everyone.
The roof downgrade (not less 1:50) should be provided with packing of dutchmans under a basic part of girders on one of load bearing walls or packing on girders of wooden dutchmans of a variable thickness.
Corbels are arranged by exhaust of the ends of rafters or roofing girders for an outer surface стенык to which butt ends the stud not less than 38 mm fastens in the thickness. The bottom edge of a roofing flooring should lean against a stud of rafters or roofing girders.
To filing of corbels can be applied: plywood in the thickness not less than 6 mm, the punched metal strips with an anticorrosive coating, boards in the thickness not less than 19 mm. In cases when carrying out of a corbel does not exceed 300 mm (at a roof downgrade 1:1 and more), filing is carried out only from boards and fastens directly to rafters (drawing 8.5,). At большей to size of carrying out of a corbel for filing bracing it is recommended to provide the device of the purlin including a basic board, nailed down to racks of a framing of a wall over a protective sheet work of a wall, and бруски, nailed down to a basic board and to a stud of rafters.
The device of corbels
In filing of corbels there should be vent holes. To prevent hit of a heater of attic flooring on vent holes in corbel filing, it is necessary, that the top of a protective sheet work of a wall settled down above top обвязочной girders in a wall, but thus the distance between top of a sheet work of a wall and a bottom of a roofing flooring should be not less than 25 mm (for fanning maintenance).
After the device of a roofing flooring and corbel filing to a stud of rafters the board which bottom should settle down not less than on 15 mm below a lower face of filing of a corbel is nailed down obverse карнизная.
Bosoms in corbels and at mansard walls in places of crossing of an attic floor or a penthouse the walls dividing adjacent inhabited blocks or fire compartments, should be divided fire-prevention diaphragms from plywood in the thickness not less than 12 mm, two layers of boards or асбестоцементного sheet.
In a pediment wall as the top stud of a framing of a wall at карнизном свесе less than 300 mm are used an extreme rafter, and at большем свесе - a chord of the same sectional view, as the wall rack, established in parallel rafters, but below them so that on them it was possible the cantilever beams provided in this case for bracing of a roofing flooring and filing of a corbel.
In cases when frontispice warming is not provided, racks of a framing of a frontispice wall surfaces are supposed to have the long party of sectional view in parallel.
At the device of a corbel with carrying out more than 300 mm the cantilever beams, which sectional view are accepted same as sectional view of rafters, than 600 mm settle down with step no more and are nailed down in a butt end to an extreme rafter and from above - to a wall chord. Between cantilever beams on chord top loose leaves, and to butt ends of cantilever beams - a front girder of the same sectional view, as a rafter are nailed down.
At the device of a corbel with carrying out less than 300 mm its load-carrying structure consists of a basic board in the thickness not less than 19 mm which fastens nails to a rafter through an exterior sheet work of a frontispice, and a front board of the same sectional view which fastens on the ends to exhausts коньковой girders and карнизной studs of rafters, and also брусков in the thickness of 38 mm which are established between these boards and nailed down to them by nails.
The frontispice sheet work at the device карнизного свеса with carrying out of a corbel less than 300 mm should be lead up to the top side of rafters, and at carrying out of a corbel more than 300 mm - to a bottom of cantilever beams.
Roofing flooring
The roofing flooring is arranged on rafters or roof frames. It is carried out solid of plywood or saw-timbers. The flooring is the base for a roof and connects a roof load-bearing framework in a horizontal direction.
The plywood applied to the device of a roofing flooring, should correspond to requirements of standards extending on it. Saw-timbers should meet the requirements of GOST 8486 to saw-timbers not below 3rd grade.
The roofing flooring from plywood should be established so that fibres of a surface of plywood have been directed at right angles to rafters.
Connections in a flooring
Connections of sheets and boards, perpendicular to a roof ridge, should be staggered on rafters.
Clearance spaces between sheets or butt ends of boards should be not less than 2 mm.
The bearer for beads of sheets parallel to the fad between rafters is carried out from брусков by sectional view not less than 38'38 mm which are nailed down to rafters by nails.
Veneer sheets fasten to rafters nails of 50 mm with step along rafters (girders) of 300 mm, edges of sheets fasten the same nails with step of 150 mm. At a thickness of sheets more than 20 mm are applied nails of 60 mm.
In a flooring from saw-timbers the width of boards should be no more than 290 mm. Boards in width to 180 mm fasten to each rafter (girder) two nails of 50 mm, and width more than 180 mm - three same nails.
Thickness of a flooring
Roof
The roof should provide protection of roof designs and at home from rain, a melt water and snow. In and places of an adjunction of a roof to other designs of the house with that end in view water taking away chantlates and plums in addition should be established.
The roof material, its structure and the device should correspond to requirements СНиП II-26 and additional requirements of the present Arch of rules.
For the device of water taking away chantlates and draining off rolled roofing materials, and also sheets from a zinc-coated steel in the thickness not less than 0,30 mm, copper in the thickness not less than 0,40 mm, aluminium alloys in the thickness not less than 0,50 mm can be used.
Roofing materials should keep within according to building size standards and rules, and also instructions, developed manufacturers of materials. Thus following additional requirements should be fulfilled:
- At packing of bitumen tiles on roofs with a downgrade 1:3 and more the width of overlapping of the top tiles on the bottom should be not less than half of size of a tile on a slope;
- At packing of bitumen tiles on roofs with a downgrade less 1:3 the width of overlapping of the top tiles on the bottom should be not less than two thirds of times a tile measure on a slope;
- Nails or the fixing brackets attaching bitumen tiles to a roofing flooring, should be covered by the top number of tiles;
- The roof from rolled materials should consist not less than of three layers pasted on bitumen mastic;
- The roof from the rolled materials, stacked on a solid flooring from materials on the basis of lumber, should have the additional base layer from , laid dry (without ) on all area of a flooring so that нахлесты all edges of panels was made not less by than 50 mm; the additional layer пергамина under a multilayered roof can to be stacked, if in position of joints of slabs has come the tape is used герметизирующая, and the surface is grounded by bitumen;
- The roof from асбестоцементных corrugated sheets keeps within on a purlin from wooden брусков sectional view not less than 60'60 mm located with step no more 400 mm;
- The coating from metal (flat and profiled), polyester sheets and sheets from polyvinylchloride keeps within on a purlin from wooden брусков sectional view not less than 38'38 mm located with step no more 250 mm.
Nails and fixing brackets
The nails applied to bracing of roofing coatings to a flooring from saw-timbers, should be made of korrozionno-proof metal or are hot-galvanised.
Nails should have sufficient length to get into a flooring not less than on 12 mm, but not to pass it through.
Nails for bracing of a roof from bitumen rolled materials and bitumen tiles should have diameter not less than 10 mm, and heads - not less than 3 mm.
Brackets for bracing of bitumen tiles and rolled materials to a flooring from plywood should be korrozionno-proof and be stemmed so that an exterior part of a bracket has been directed in parallel a corbel. Brackets should have length of a stemmed part not less than 20 mm, a thickness - not less than 1,6 mm, width - 25 or 11 mm.
Fanning of roofs
For prevention of accumulation of a moisture in designs of the warmed roofs it is necessary to arrange the prospirits, allowing to deduce outside damp air from space over a heater of attic flooring or бесчердачной roofs.
In скатных and flat roofs prospirits are arranged in the bottom filing of a corbel in the form of cuts and apertures. And cuts it is possible not to do an aperture, if the bottom filing of a corbel is carried out from the punched sheets.
In pitched roofs in addition to карнизным prospirits in opposite frontispices under the fad in the form of an aperture closed жалюзийной by a lattice are arranged.
For hit prevention in ventilated spaces of roofs of snow and insects on prospirits grids from plastic or metal with an anticorrosive coating should be established.
In the bottom part mansard (вальмовых) prospirits do not suit roofs.
The area of prospirits in pitched roofs should make not less than 1/300, and in flat roofs - not less than 1/150 areas of a ventilated lot of attic flooring; in the houses erected in III and IV climatic neighbouring communes, the area of prospirits in all cases should be not less than 1/50 areas of a ventilated lot of attic flooring.
Prospirits should settle down:
In regular intervals on the roof opposite sides;
So that not less than 25 % of a required area of prospirits it was necessary on an upper part roofs (frontispice);
So that not less than 25 % of a required area of prospirits it was necessary on the bottom part roofs (corbel).
In need of pitched roofs for fanning prospirits in the fad and the roof windows which design should provide protection of attic space against hit of a rain, snow and insects can be arranged also.
Each space between roofing girders in solar roofs or rafters in pitched roofs should have the vent hole.
If the condition 8.7.9 cannot be executed, on roofing girders or rafters under a roofing flooring should be established cross-section by sectional view 38'38 mm for pass of air from one space between roofing girders or rafters in another.
Between an upper surface of a thermal protection and the bottom party of a roofing flooring the hollow space in height not less than 60 mm anyway should be left.
The ceiling thermal protection should keep within so that not to limit free movement of an air stream through prospirits in a roof.
Access to an attic floor
In an attic-floor room the hatch-manhole, if should be provided:
The premise area makes not less than 3,0 м2;
Length or width of a premise not less than 1,0 m;
The floor-to-ceiling height on this area makes not less than 0,6 m.
The size of the hatch should be not less than 500'700 mm.
The hatches guideing on an attic floor or in a premise under a roof, take place within the precincts of an attic floor or in attic flooring and should have doors or covers with locking devices.
Drains and rainwater pipes
Drains for different sorts of roofs should correspond to building size standards and standards for roofing and sanitary-engineering works.
For elimination of an icing of water waste devices it is recommended to carry out heating карнизного a lot of a roof and rainwater pipes devices of the distributed electroheating.
The house roof consists of a wooden load-bearing framework to which fastens:
- From above - a solid roofing flooring or a purlin on which the roof providing necessary protection against penetration of an atmospheric precipitation and a melt water settles down;
- From below - ceiling filing over which the vapour barrier and a heater providing a necessary thermal protection settles down.
In houses in height 3 floors ceiling filing should be executed from sheets of type sheets of type ГВЛ in the thickness not less than 12,5 mm (under requirements of fire safety).
The structure of designs and flat roofs of the house includes the corbels providing partial tap of thawed with roof thawed and rain water from external walls, and into structure of designs of pitched roofs - if necessary, also face frontispices with corbels over them.
In designs of roofs it is necessary to provide the vent holes, allowing to deduce outside the damp air getting on an attic floor from heated premises.
For a fastening of elements of a framing of roofs the fixing parts which have been not provided in the present section (for example, plates) can be used. In this case durability of connections should be not less provided in the provided ways that should be confirmed by calculations or to trials
In pitched roofs the load-bearing framework consists of girders of attic flooring, rafters, and also коньковых boards or girders and, at necessity, intermediate bearers of rafters. The bottom ends of rafters lean against a framing of exterior load bearing walls, and top can incorporate among themselves through a board without vertical bearers or with on a girder which in turn leans against the racks transferring loading on an internal load bearing wall or on lintel. As intermediate bearers of rafters can be used: beam ties; penthouse walls; the racks transferring loading on a framing of attic flooring; the compressed inclined braces
Possibility of application of wooden roof frames of factory manufacturing or collected on the earth is provided also.
Load-bearing framework of flat roofs are the roofing girders combining functions of rafters and girders of attic flooring. Sectional views, spans and steps of elements of a load-bearing framework of a roof should pay off on depending on the accepted design load on them, defined according to requirements
For roofs at width of the house no more and a step of wooden load-carrying structures of a framing (rafters, girders), not exceeding 600 mm, sectional views of elements of a framing it is supposed to accept than 9,8 m without calculation depending on their span.
If loading is transferred to girders of attic flooring through racks from rafters height of sectional view of such girders should exceed not less than on 25 mm height. In houses in height 3 floors the width of sectional view of open rafters, roofing girders and lintels бесчердачных coatings under requirements of fire safety should be not less than 89 mm.
The floor beams bearing a ceiling from wood fibreboards, for prevention of twisting along beads of the bottom side should be fixed by the device of a purlin or vertical diagonal communications.
In cases, when it is required, that the roof has sustained the additional uniformly distributed loading created by heavy roofing materials (such as a concrete roofing slab), possibility of perception of this additional loading should be checked by calculation.
Diagonal rafters on ridges and under ендовами roofs should be executed from the converted timber which height of sectional view is more than height of sectional view of ordinary rafters not less than on 50 mm at width of sectional view not less than 38 mm.
In cases of use of integral rafters on length, roofing girders and girders of attic flooring joints of elements making them should settle down over vertical bearers.
Rafters, roofing girders, and also girders of attic flooring should be doubled on each party of apertures in a roof or the attic flooring, exceeding on width distance between two rafters or girders.
Elements of a framing of a roof should be made of a pine wood not below 2nd grade in accordance with GOST 8486.
Load-bearing framework of a pitched roof with a downgrade 1:3 and more, collected on site
In pitched roofs with a downgrade 1:3 and more vertical bearer for the top ends of rafters under the fad usually is not arranged. Horizontal распор rafters in these cases it is perceived by girders of attic flooring which simultaneously are string pieces.
Rafters of opposite slopes should settle down directly against each other and to incorporate the top ends through a board in the thickness not less than 19 mm end-to-end or when girders of attic flooring are made of the elements connected among themselves , - to displacement for own thickness.
Rafters and girders of attic flooring should lean directly against wood structures of external walls.
On basic lots it is necessary for rafters to give the certain form to provide equal platforms опирания.
Connections of the basic ends of rafters and girders of attic flooring, and also elements of girders of attic flooring among themselves, perceiving horizontal распор rafters, are carried out on nails. The ends of rafters and girders incorporate thus , the ends of elements of integral girders on length - внахлест or in a butt end to a battening plate from a bar of the same sectional view. Quantity of nails in each connection of rafters with girders depending on a roof downgrade. Used for reduction of spans and the sizes of sectional view of rafters intermediate bearers in the form of string pieces should be produced from converted timber by sectional view not less than 38'89 mm. String pieces in length more than 2,4 m should incorporate among themselves near to the middle not cutting elements (communications) by sectional view not less than 19'89 mm, located at right angles to string pieces.
Load-bearing framework of a pitched roof with a downgrade less 1:3, collected on site
In pitched roofs with a downgrade less 1:3 the top ends of rafters follows on a girder sectional view not less than 38'140 mm, stacked on vertical racks sectional view not less than 38'89 mm which are established on a stud of an internal load bearing wall with step of 1,2 m.
If necessary spans girders between supporting poles can be increased.
In roofs with a small downgrade for space formation between the top stud of walls and a roofing flooring stacked on rafters, sufficient for placing in it of a heater and a ventilated air interlaminar layer, the bottom basic ends of rafters follows опирать not on the top stud of walls, and on the basic board located above a stud sectional view not less than 38'89 mm. This board keeps within on girders of attic flooring and is nailed down to each girder. Rafters are nailed down to a basic board.
In cases when the certain lot of an external wall is displaced in the house under the general roof, girders of attic flooring supporting these wall keep within on a stud of a framing of an external wall.
The device of a framing of a pitched roof at the external wall displaced in the house
Under rafters on this lot of a wall the basic wall from vertical racks and the stud of the same sectional view laid on them, as an external wall framing is arranged. Racks are established on an external wall stud under each rafter. Rafters should lean against a stud of a basic wall and be attached to it by nails. An intermediate bearer in pitched roofs with a downgrade less 1:3 basic walls with the top both bottom stud and racks sectional view 38'89 mm which are established in plane with rafters and girders of attic flooring can be and are nailed up to them.
Intermediate bearers can be also the compressed inclined braces under rafters which are produced from converted timber by sectional view not less than 38'89 mm and are established from everyone стропилины to an internal load bearing wall at an angle not less than 45 ° to a horizontal.
Instead of the load-bearing framework of pitched roofs collected on site, the roof frames made industrially or collected preliminary on a building site can be applied.
Designing of roof frames, including butt joints of their elements, should be carried out according to requirements СНиП II-25.
Roof frames with the compressed elements of the lattice which length exceeds 1,8 m, should have cross-section system of communications in order to avoid a longitudinal bending down.
The system of communications to consist of boards sectional view not less than 19'89 mm which have been nailed down at right angles to elements of a lattice near to their middle a minimum by two nails in length of 60 mm for each element.
Elements of roof frames are not supposed to be kerfed, made an incision, bored through, causing their loosening if it is not provided in workshop drawings of elements of trusses.
Framing of a flat roof
The height of sectional view of roofing girders can be insufficient for placing in spaces between girders of a heater of a demanded thickness and ventilation space maintenance according to In such cases height of sectional view of roofing girders should be increased by necessary size.
Roofing girders fasten to a stud of load bearing walls two nails the in length of 80 mm вкосую everyone.
The roof downgrade (not less 1:50) should be provided with packing of dutchmans under a basic part of girders on one of load bearing walls or packing on girders of wooden dutchmans of a variable thickness.
Corbels are arranged by exhaust of the ends of rafters or roofing girders for an outer surface стенык to which butt ends the stud not less than 38 mm fastens in the thickness. The bottom edge of a roofing flooring should lean against a stud of rafters or roofing girders.
To filing of corbels can be applied: plywood in the thickness not less than 6 mm, the punched metal strips with an anticorrosive coating, boards in the thickness not less than 19 mm. In cases when carrying out of a corbel does not exceed 300 mm (at a roof downgrade 1:1 and more), filing is carried out only from boards and fastens directly to rafters (drawing 8.5,). At большей to size of carrying out of a corbel for filing bracing it is recommended to provide the device of the purlin including a basic board, nailed down to racks of a framing of a wall over a protective sheet work of a wall, and бруски, nailed down to a basic board and to a stud of rafters.
The device of corbels
In filing of corbels there should be vent holes. To prevent hit of a heater of attic flooring on vent holes in corbel filing, it is necessary, that the top of a protective sheet work of a wall settled down above top обвязочной girders in a wall, but thus the distance between top of a sheet work of a wall and a bottom of a roofing flooring should be not less than 25 mm (for fanning maintenance).
After the device of a roofing flooring and corbel filing to a stud of rafters the board which bottom should settle down not less than on 15 mm below a lower face of filing of a corbel is nailed down obverse карнизная.
Bosoms in corbels and at mansard walls in places of crossing of an attic floor or a penthouse the walls dividing adjacent inhabited blocks or fire compartments, should be divided fire-prevention diaphragms from plywood in the thickness not less than 12 mm, two layers of boards or асбестоцементного sheet.
In a pediment wall as the top stud of a framing of a wall at карнизном свесе less than 300 mm are used an extreme rafter, and at большем свесе - a chord of the same sectional view, as the wall rack, established in parallel rafters, but below them so that on them it was possible the cantilever beams provided in this case for bracing of a roofing flooring and filing of a corbel.
In cases when frontispice warming is not provided, racks of a framing of a frontispice wall surfaces are supposed to have the long party of sectional view in parallel.
At the device of a corbel with carrying out more than 300 mm the cantilever beams, which sectional view are accepted same as sectional view of rafters, than 600 mm settle down with step no more and are nailed down in a butt end to an extreme rafter and from above - to a wall chord. Between cantilever beams on chord top loose leaves, and to butt ends of cantilever beams - a front girder of the same sectional view, as a rafter are nailed down.
At the device of a corbel with carrying out less than 300 mm its load-carrying structure consists of a basic board in the thickness not less than 19 mm which fastens nails to a rafter through an exterior sheet work of a frontispice, and a front board of the same sectional view which fastens on the ends to exhausts коньковой girders and карнизной studs of rafters, and also брусков in the thickness of 38 mm which are established between these boards and nailed down to them by nails.
The frontispice sheet work at the device карнизного свеса with carrying out of a corbel less than 300 mm should be lead up to the top side of rafters, and at carrying out of a corbel more than 300 mm - to a bottom of cantilever beams.
Roofing flooring
The roofing flooring is arranged on rafters or roof frames. It is carried out solid of plywood or saw-timbers. The flooring is the base for a roof and connects a roof load-bearing framework in a horizontal direction.
The plywood applied to the device of a roofing flooring, should correspond to requirements of standards extending on it. Saw-timbers should meet the requirements of GOST 8486 to saw-timbers not below 3rd grade.
The roofing flooring from plywood should be established so that fibres of a surface of plywood have been directed at right angles to rafters.
Connections in a flooring
Connections of sheets and boards, perpendicular to a roof ridge, should be staggered on rafters.
Clearance spaces between sheets or butt ends of boards should be not less than 2 mm.
The bearer for beads of sheets parallel to the fad between rafters is carried out from брусков by sectional view not less than 38'38 mm which are nailed down to rafters by nails.
Veneer sheets fasten to rafters nails of 50 mm with step along rafters (girders) of 300 mm, edges of sheets fasten the same nails with step of 150 mm. At a thickness of sheets more than 20 mm are applied nails of 60 mm.
In a flooring from saw-timbers the width of boards should be no more than 290 mm. Boards in width to 180 mm fasten to each rafter (girder) two nails of 50 mm, and width more than 180 mm - three same nails.
Thickness of a flooring
Roof
The roof should provide protection of roof designs and at home from rain, a melt water and snow. In and places of an adjunction of a roof to other designs of the house with that end in view water taking away chantlates and plums in addition should be established.
The roof material, its structure and the device should correspond to requirements СНиП II-26 and additional requirements of the present Arch of rules.
For the device of water taking away chantlates and draining off rolled roofing materials, and also sheets from a zinc-coated steel in the thickness not less than 0,30 mm, copper in the thickness not less than 0,40 mm, aluminium alloys in the thickness not less than 0,50 mm can be used.
Roofing materials should keep within according to building size standards and rules, and also instructions, developed manufacturers of materials. Thus following additional requirements should be fulfilled:
- At packing of bitumen tiles on roofs with a downgrade 1:3 and more the width of overlapping of the top tiles on the bottom should be not less than half of size of a tile on a slope;
- At packing of bitumen tiles on roofs with a downgrade less 1:3 the width of overlapping of the top tiles on the bottom should be not less than two thirds of times a tile measure on a slope;
- Nails or the fixing brackets attaching bitumen tiles to a roofing flooring, should be covered by the top number of tiles;
- The roof from rolled materials should consist not less than of three layers pasted on bitumen mastic;
- The roof from the rolled materials, stacked on a solid flooring from materials on the basis of lumber, should have the additional base layer from , laid dry (without ) on all area of a flooring so that нахлесты all edges of panels was made not less by than 50 mm; the additional layer пергамина under a multilayered roof can to be stacked, if in position of joints of slabs has come the tape is used герметизирующая, and the surface is grounded by bitumen;
- The roof from асбестоцементных corrugated sheets keeps within on a purlin from wooden брусков sectional view not less than 60'60 mm located with step no more 400 mm;
- The coating from metal (flat and profiled), polyester sheets and sheets from polyvinylchloride keeps within on a purlin from wooden брусков sectional view not less than 38'38 mm located with step no more 250 mm.
Nails and fixing brackets
The nails applied to bracing of roofing coatings to a flooring from saw-timbers, should be made of korrozionno-proof metal or are hot-galvanised.
Nails should have sufficient length to get into a flooring not less than on 12 mm, but not to pass it through.
Nails for bracing of a roof from bitumen rolled materials and bitumen tiles should have diameter not less than 10 mm, and heads - not less than 3 mm.
Brackets for bracing of bitumen tiles and rolled materials to a flooring from plywood should be korrozionno-proof and be stemmed so that an exterior part of a bracket has been directed in parallel a corbel. Brackets should have length of a stemmed part not less than 20 mm, a thickness - not less than 1,6 mm, width - 25 or 11 mm.
Fanning of roofs
For prevention of accumulation of a moisture in designs of the warmed roofs it is necessary to arrange the prospirits, allowing to deduce outside damp air from space over a heater of attic flooring or бесчердачной roofs.
In скатных and flat roofs prospirits are arranged in the bottom filing of a corbel in the form of cuts and apertures. And cuts it is possible not to do an aperture, if the bottom filing of a corbel is carried out from the punched sheets.
In pitched roofs in addition to карнизным prospirits in opposite frontispices under the fad in the form of an aperture closed жалюзийной by a lattice are arranged.
For hit prevention in ventilated spaces of roofs of snow and insects on prospirits grids from plastic or metal with an anticorrosive coating should be established.
In the bottom part mansard (вальмовых) prospirits do not suit roofs.
The area of prospirits in pitched roofs should make not less than 1/300, and in flat roofs - not less than 1/150 areas of a ventilated lot of attic flooring; in the houses erected in III and IV climatic neighbouring communes, the area of prospirits in all cases should be not less than 1/50 areas of a ventilated lot of attic flooring.
Prospirits should settle down:
In regular intervals on the roof opposite sides;
So that not less than 25 % of a required area of prospirits it was necessary on an upper part roofs (frontispice);
So that not less than 25 % of a required area of prospirits it was necessary on the bottom part roofs (corbel).
In need of pitched roofs for fanning prospirits in the fad and the roof windows which design should provide protection of attic space against hit of a rain, snow and insects can be arranged also.
Each space between roofing girders in solar roofs or rafters in pitched roofs should have the vent hole.
If the condition 8.7.9 cannot be executed, on roofing girders or rafters under a roofing flooring should be established cross-section by sectional view 38'38 mm for pass of air from one space between roofing girders or rafters in another.
Between an upper surface of a thermal protection and the bottom party of a roofing flooring the hollow space in height not less than 60 mm anyway should be left.
The ceiling thermal protection should keep within so that not to limit free movement of an air stream through prospirits in a roof.
Access to an attic floor
In an attic-floor room the hatch-manhole, if should be provided:
The premise area makes not less than 3,0 м2;
Length or width of a premise not less than 1,0 m;
The floor-to-ceiling height on this area makes not less than 0,6 m.
The size of the hatch should be not less than 500'700 mm.
The hatches guideing on an attic floor or in a premise under a roof, take place within the precincts of an attic floor or in attic flooring and should have doors or covers with locking devices.
Drains and rainwater pipes
Drains for different sorts of roofs should correspond to building size standards and standards for roofing and sanitary-engineering works.
For elimination of an icing of water waste devices it is recommended to carry out heating карнизного a lot of a roof and rainwater pipes devices of the distributed electroheating.
