fundamentals of architectural technology - roofing

7/29/2019 Fundamentals of Architectural technology - Roofing

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Politecnico di Torino School of Architecture

BUILDING

TECHNOLOGIES

Technological principles Prof. Roberto Pagani


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The building envelopeseparates the outside from the inside.

The building envelope is the structure that separates the building occupant

from outdoor conditions. It's a major factor in determining a building's energy

use. The components that make up a building envelope include:

> Foundation

> Wall Systems

> Fenestration: Windows, Doors and Skylights

> Roofing

Innovative building envelope technologies currently under development willmake tomorrow's buildings more efficient, durable, comfortable, and adaptable

than ever. It's also important that these materials and products ultimately

complement your whole-building design approach.


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Politecnico di Torino School of Architecture

ROOFING

Copertura

Technology principles Prof. Roberto Pagani


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The building envelopeseparates the outside from the inside.

The building envelope is the structure that separates the building occupant

from outdoor conditions. It's a major factor in determining a building's energy

use. The components that make up a building envelope include:

> Foundation

> Wall Systems

> Fenestration: Windows, Doors and Skylights

> Roofing

Innovative building envelope technologies currently under development willmake tomorrow's buildings more efficient, durable, comfortable, and adaptable

than ever. It's also important that these materials and products ultimately

complement your whole-building design approach.


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0 General definitions

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A roof is the covering on the uppermost part of a building.

The purpose of a roof is to protect the building and its contents from the

effects of weather.

The characteristics of a roof are dependent upon the purpose of the building

that it covers, the available roofing materials and the local traditions of

construction and wider concepts of architectural design and practice and mayalso be governed by local or national legislation.

In most countries a roof protects primarily against rain.

Depending upon the nature of the building, the roof may also protect against

heat, against sunlight, against cold and against wind.

If the roof is the covering for a house, then all these protective functions are

called into play. Other types of structure, for example, a garden conservatory,

might utilize roofing that protects against cold, wind and rain but admits light. A

verandah may be roofed with material that protects against sunlight but admits

the other elements.

ROOFINGCopertura

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The elements in the design of a roof are:

> MATERIALIt may range from banana leaves, wheaten straw or seagrass tolamininated glass, aluminium sheeting and precast concrete. In many

parts of the world ceramic tiles have been the predominant roofing

material for centuries.

> CONSTRUCTION

It is determined by its method of support and how theunderneath space is bridged and whether or not the roof ispitched.The pitch is the angle at which the roof rises from its lowest tohighest point.Most domestic architecture, except in very dry regions, hasroofs which are sloped, or pitched.

ROOFINGCopertura

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> FUNCTIONIt includes its durability and how well it serves of its required

purposes. The durability of a roof is a matter of concern inboth material and construction, because in general the roof isthe least accessible part of a building for purposes of repair

and renewal, while its damage or destruction can have seriouseffects

ROOFINGCopertura

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There are two essential parts to a roof:>its supporting structure> its outer skin, or uppermost weatherproof layer.In a very small minority of buildings, the outer layer is also a self-supporting structure

In general a roof is composed of different elements:

> Support

> Outer layer

> Insulation

> Drainage

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ROOFINGCopertura

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1 Support

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1 Support

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1 Support

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1RAFTERS at 90 cmpuntoni a 90 cm

2ROOF BATTENS at 90 cmlistelli a 90 cm

3 SMALL ROOF BATTENSlistellini

4 TAVOLATOplanking

5 ROOF SHEETINGmanto di copertura

6 COLLAR TIEcatena

7WIND BRACEmonaco

8 PROPpuntello

9 CLAMPstaffa

10 RIDGEcolmo

11 BEARING STRUCTUREstruttura portante

WOOD STRUCTUREStruttura portante in legno


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1 Support

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1 Support

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A simple ridged roof consists of inclined rafters that rest on horizontalwall-plates on top of each wall.

The top ends of the rafters meet at the horizontal ridge plate or ridgebeam. Horizontal purlins are fixed to the rafters to support the roofcovering. Heavier under purlin are used to support longer rafter spans.Tie beams or ceiling joists, are connected between the lower ends ofopposite rafters to prevent them from spreading and forcing the wallsapart. Collar beams or collar ties may be fixed higher up between

opposite rafters for extra strength.

In architecture or structuralengineering, a purlin (or purline)is a horizontal structural memberin a roof.

Purlins support the loads fromthe roof deck or sheathing andare supported by the principalrafters and/or the building walls.


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1 Support

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1 Support

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1FLOOR BLOCKSblocchi per solaio

2BEARING BEAMtrave portante

3 INSULATIONisolamento

4 PLASTERintonaco

5 CAVITY WALLparete a cassavuota

6 INSULATIONisolante 10-12 cm

7BATTENSlistelli

8 ROOF SHEETING

manto di copertura9 GUTTER

grondaia10 DROP BREAKER

rompigoccia

CONCRETE STRUCTUREStruttura portante in laterocemento


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1 Support

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2 Outer layer

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2 Outer layer

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2 Outer layer

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This part of the roof shows great variation dependent uponavailability of material.

In simple vernacular architecture, roofing material is oftenvegetative, such as thatches of different materials, the mostdurable being sea grass with a life of perhaps 40 years.

In areas with an abundance of timber, wooden shingles are used,while in some countries the bark of certain trees can be peeled offin thick, heavy sheets and used for roofing.


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2 Outer layer

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CAMEROON_ a house roofed with banana leaves

JAPAN_rice straw thatch

ENGLAND_slate

l


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2 Outer layer

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HUNGARY_terracotta tiles

ISRAEL_the flat roofs of the Middle East

SCANDINAVIA_the steeply pitched, gabled roofs

2 O l


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2 Outer layer

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CHINA_the overhanging eaves

FINDHORN_green roof with solar panels

ISLAND OF SYLT_reed thatch

2 O t l


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2 Outer layer

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NORTH DEVON, ENGLAND _a roof tiled in

imitation of thatch

AUSTRIA_Wooden shingles

USA_bitumen

3 I l ti


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3 Insulation

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3 I l ti


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3 Insulation

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Insulated layers can be placed in different positions according to the levelof thermal insulation required for the roof.

Traditionally roofs were not insulated but according to the latest laws,insulation is strictly necessary to reach required levels of transmittance.

1 ROOF SHEETINGmanto di copertura

2 UNDER TILE VENTILATIONventilazione sottotegola

3 BEARING STRUCTUREstruttura portante

4 VENTILATED SPACEambiente ventilato

NOT INSULATEDNOT VENTILATED

NOT INSULATEDVENTILATED

3 I l ti


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3 Insulation

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1 ROOF SHEETING

manto di copertura2 UNDER TILE VENTILATION

ventilazione sottotegola3 BEARING STRUCTURE

struttura portante

4 VENTILATED SPACE

ambiente ventilato5 INSULATION LAYER

strato isolante6 VAPOUR CONTROL LAYER

barriera al vapore

WARM ROOFTetto caldo

COLD ROOFTetto freddo

3 I l ti


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3 Insulation

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Some roofing materials, particularly those of natural fibrous material,such as thatch, have excellent insulating properties.

For those that do not, extra insulation is installed under the outer layer.

1 ROOF SHEETING (TILES)manto di copertura

2 RAFTERS andROOF BATTENS

puntoni e listelli3 WATERPROOF SHEET

impermeabilizzante4 VENTILATION CAVITY

canale di ventilazione5 INSUALTION MATERIAL

materiale isolante6 VAPOUR BARRIER

barriera al vapore7 INTERNAL COAT

rivestimento interno

4 D in ge


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4 Drainage

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4 Drainage


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4 Drainage

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The primary job of most roofs is to keep out water.

The large area of a roof repels a lot of water, which must bedirected in some suitable way, so that it does not cause damage orinconvenience.

4 Drainage


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4 Drainage

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1FLOORsolaio

2VAPOUR BARRIERbarriera al vapore

3 INSULATIONisolamento

4 WATERPROOF SHEETstrato impermeabilizzante

5 SOILterriccio

6 METAL COVERcopertina in alluminio

7NON BEARING WALL

parete non portante8 BEARING WALL

parete portante

FLAT ROOFTetto piano

fundamentals of architectural technology - roofing

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