flat roofs

Transcription

flat roofs

Pág. 1
Sesión 1/4
Asignatura
Clave Máster y Curso
FLAT ROOFS
ROOFS
Construction II. Systems. 2nd year
Construction Area
Academic Year 2014-2015
Review 04/03/2015
Authors: Carlos Gelpí Almirall / Xavier Belil / Josep Olivé
Pàg. 2/75
Àrea de Construcció
Construcció II
AR012
Index
1.1. Definition
1.1. definition
1.2. water tightness principals
2. Design principals
2.1. dimensioning of roof slopes and inclinations
2.2. main layers of a flat roof
3. Singular points
4. Typologies
4.1. Conventional (cat. No invertida o convencional)
4.2. Ventilated (cat. Ventilada)
4.3. Inverted, also Upside-down (cat. invertida)
4.4. Green roofs (cat. enjardinada)
4.5. Flooded roofs (cat. inundada)
4.6. Roofs for the traffic of vehicles (cat. per trànsit rodat)
5. Installation and execution controls
6. Information sources
General definition
Flat roofs are those which have a slope < 5%.
Pàg. 3/75
Definition l Design l Singular points I Typologies l Installation and control l Information sources
AR012
Construcció II
INCLINADES > 5%
5%
FLAT ROOFS < 5%
Font: Construir la arquitectura, Andrea Deplazes. Ed. GG
AR012
Construcció II
Pàg. 4/75
Water tightness principals
1. Absolute continuity of the water tightness envelope
The material which makes this function is the one which will always be absolutely
waterproof, both conceptually and materially.
2. Geometry: sealing (Cat. Segellat) and overlapping (Cat. Encavalcament)
Usually, although not always, the covering materials are not continuous. In these cases,
we rely water tightness on the water tightness of the joints between the pieces using:
- Chemical sealing between pieces: welding, chemical merging, adherence, etc..
- Secondarily, the slope and overlap between pieces as well.
Slope of the roofs according to CTE
Flat roofs are those which have a slope < 5%. However, this value is an average
value (of most of the slopes) of the roof because, usually, some slopes can have an
inclination much higher if the routing between flashing and drain is small.
Construcció II
Pàg. 5/75
steep
slopes
regulatory
slopes
AR012
Slopes of flat roofs
*Use
*Protection
*Pedestrians
*Trafficable
*Slopes in %
*Vehicles
*Non trafficable
*Green roofs
*fixed flooring
*Floating (loose laid) flooring
*traffic layer
*Gravel
*Self-protected sheet
*Topsoil
Geometry of the slopes
AR012
Construcció II
Pàg. 6/75
CTE DB HS 1 2.4 ROOFS
-GEOMETRY OF THE ROOF. Determining the project’s roof geometry taking into
consideration the water drains.
The drains must be separated from the roof’s perimeter minimum 30cm
according to CTE.
Construcció II
Pàg. 7/75
Dimensioning the sides
CTE DB HS 1
2.4 CUBIERTAS
-WATER EVACUATION: Selection of the minimum number of the necessary water evacuation elements.
According to CTE, the minimum number of water evacuation elements will be two, and will depend on the
roof’s surface. CTE DB HS 5 Table 4.6
*Number of drains needed according to the roof’s surface
*Surface of the
roof’s horizontal
projection (m2)
*Number of drains
Selection of the surface of the formation of slope referred to the building’s roof surface.
CTE DB HS 5 Table4.6 . If we are not able to place the minimum number of drainpipes, we must place at
least two overflows (Cat. rebosaderos) and each one on different roof limits.
-MAXIMUM SURFACE FOR A DOWNPIPE. The precipitation measurements data will determine the
diameter of these elements, not the number of them.
AR012
*Diameter of the water downpipes for a precipitation of 100 mm/h
*Surface of the
roof’s horizontal
projection (m2)
We must apply a correction factor for other precipitation values. (see CTE DB HS 5)
*Nominal diameter for
downpipes (mm)
AR012
Construcció II
Pàg. 8/75
Characteristics of the slopes
- Recommended (and regulatory) not to exceed slopes more than 5% and less than 1%.
- Minimum thickness of the layer that forms the slope is 30mm and maximum 150mm.
According to CTE DB HS 5 4.2.1.3
- Expansion joints (with a thickness of 30mm) must be provided every 10-15 linear
meters and over all the perimeter in contact with elements that cross the roof such as:
railings, chimneys, parapets, ledges, etc.
-If the pavement is fixed on mortar or concrete, the joints must make grids smaller than
5m on every side.
- We must respect and maintain the structural expansion joints of the building.
- The drains (or lowest point of the roof) must be separated by at least 30cm from the
limits of the roof, in the case of a vertical drain.
Pàg. 9/75
Main layers of a flat roof
1. SUPPORT OR STRUCTURAL BASE:
(Cat. Suport o base estructural)
- Depends on the constructive system of the building.
2. SLOPE FORMATION SYSTEMS
(Cat. Sistema de formació de pendents)
- Provides slope to the roof for the evacuation of water.
3. VAPOR BARRIER:
(Cat. Barrera de vapor)
Construcció II
AR012
Its own base structure / Cellular concrete / Mortars /
Lightened mortars (perlite) / Leveling mortars
(Cat. Pròpia base estructural/Formigó cel·lular / Morters alleugerits
(perlita) /Morters de regulació)
Polyethylene sheet / Kraft paper/
- Its placement will depend on the section of roof’s hygro-thermal calculation
Bitumen sheets / Metallic foils
and on the environmental conditions. It cuts water vapor in order to avoid
condensations.
Làmines de betum/ Làmines metàl·liques)
- It can also prevent the entrance of air and dust from the
exterior.
4. WATERPROOF LAYER:
(Cat. Impermeabilitzant)
- It is the layer in charge of ensuring watertight ness of the roof.
5. INSULATION:
(Cat. Aïllament)
Wooden / Concrete / Metallic structures
(Cat. Estructures de: Fusta / Formigó / Metàl·liques)
- Responds to a study of the energetic demand according to the climatic
conditions of the environment where the building is placed. Its function is to
control the transfer of thermal energy between the interior and exterior of the
building and to ensure its interior thermal comfort.
6. SEPARATING OR DIFUSING LAYERS:
(Cat. Capes separadores o difusores)
- Avoid direct contact between chemically incompatible materials.
- Avoid puncturing the waterproofing layer.
- Avoid adherence of the waterproofing layer
- Prevent the pass of soils in gravel and green roofs.
7. PROTECTING OR FINISHING LAYER:
(Cat. Capa de protecció o acabat)
Layer put down to respond to the direct actions of the exterior elements on
top of the roof (UV rays, rain, snow, wind, etc.)
(Cat. Làmines de polietilè / Paper Kraft /
Precast : Bituminous foils / Synthetic sheets
On site: Paintings applied using a roller or projected
paintings
(Cat. Prefabricats : Làmines bituminoses / Làmines sintètiques
In situ: Pintures aplicades amb rodet o projectades)
Rigid. Polystyrene / cellular glass / cork /
polyurethane. Not rigid (using chambers) glass wool /
polyurethane / rock wool
(Cat. Rígids. Poliestirè / vidre cel·lular / suro / poliuretà
No rígids (per cambres) llana de vidre / /Poliuretà / Llana de
roca)
Geotextiles with different densities / PVC / Reinforced
geotextile with polyurethane membrane / etc.
(Cat. Geotèxtils de diverses densitats/ PVC / Geotèxtil armat amb
malla de poliuretà/ etc.)z
Flat trafficable roof: Ceramic flooring / Floating flooring
Flat non trafficable roof: Heavy protection/ Gravel / Concrete
Green flat roof: Vegetable soil and vegetation
Industrial roof: Metallic sheet / Deck
(see classification table)
(cat. Plana Transitable: Paviment ceràmic / Paviment flotant
Plana No transitable: Protecció pesada / Grava / Formigó
Plana enjardinada: Terra Vegetal i vegetació
Coberta Industrial: Xapa Metàl·lica / Deck)
Pàg. 10/75
Singular points
AR012
Construcció II
CTE DB HS 1 2.4. CUBIERTAS 2.4.4. Singular points conditioning factors:
The CTE DB HS, Spanish Building Code, numbers and describes the particularities
which all singular points have to fulfill and are considered in CTE.
The main points are:
- Link with vertical elements
- Drains and overflows
- Expansion joints
- Elements that cross the roof.
- Fastening elements on roofs
- Access and openings.
AR012
Construcció II
Pàg. 11/75
Links with vertical wall face
Waterproof layer
- Overlaps,
reinforcement and
minimum dimensions
in singular points
according to CTE are
mandatory.
Vertical wall
Waterproof layer
Protection
Figure 2.13 Encounter of the roof with a vertical wall face.
Protection
Drain and overflow gutter
Vertical wall
Waterproof layer
Lowered
support
Overflow gutter
Construcció II
Pàg. 12/75
AR012
Figure 2.15 Overflow gutter
Drain
Figure 2.14 Lowered support around the drains
Drains
Horizontal drainage
Drains and vertical precast drainages
(cat. Bonera i desguàs vertical prefabricats)
Construcció II
Pàg. 13/75
AR012
Drain dome
(cat. Morrió / paragraves)
Gully drain
Siphonic drain
(cat. Bonera sifònica)
(cat. Desguàs horizontal)
Pàg. 14/75
Expansion joints. Finishing layers
Types of obligatory joints:
1. Joints from the own structure every 30 m
2. Joints of the formation of slopes every 10-15 m
Figure 18. Example of an expansion joint
and roof’s perimeter. Width of the joint of 30 mm
minimum. (CTE DB HS1 Cubiertas).
3. Flooring joints on trafficable roofs every 5 linear
Construcció II
1.
meters and around all the perimeter.
2.
AR012
Figure 19. Example of a roof joint
3.
Figure 20. Example of a protection layer joint.
Expansion joints. Limits
Construcció II
- Expansion joints (with a thickness of
30mm) must be provided every 10-15
linear meters and over all the perimeter in
contact with elements that cross the roof
such as: railings, chimneys, etc.
- Joints must be made in all those rigid
layers that can undergo deformations or
create unwanted forces with thermal
origins; the most common ones are:
slope formation layers and adhered rigid
floorings.
AR012
Pàg. 15/75
-The rigid pieces which make up
flashings must be independent from the
roof’s finishing leafs.
-If the pavement is fixed on mortar or
concrete, the joints must make grids
smaller than 5m on every side.
-We must maintain the structural joints of
a building.
Pàg. 16/75
Elements which cross the roof
AR012
Construcció II
Solution installing vertical elements (walls) and solving the perimeter.
Others:
- Elements that make up a roof.
- Machines fastenings on top of the roofs.
Section of the layout of building services on a roof. Solution of “INTEMPER” products.
AR012
Construcció II
Pàg. 17/75
Elements which cross the roof and fastening elements
Example of the solution for a trafficable flat roof with mortar slabs that incorporates insulation. In
the photographs below we see the details of the installation machine’s fastening element, placed,
floating, on top of the finishing layer, and the waterproofing treatment of the structural elements
which cross the roof.
AR012
Construcció II
Pàg. 18/75
Fastening elements
Regulatory norms for fastening
elements:
Try to always avoid puncturing the
waterproofing layer with the fastening
elements
Place the fastening elements for hand
railings, antennas, etc. on vertical
walls.
AR012
Construcció II
Pàg. 19/75
Security features
An indispensable element for a flat roof that is trafficable only for the maintenance of installation
elements and that does not have any kind of hand railing, is what is known as a horizontal lifeline: a
wire which offers security on sites and from where workmen hang using a harness.
AR012
Construcció II
Pàg. 20/75
Skylights. Precast skylights.
Dome-type precast skylights placed on top of flat roofs with self-protected asphalted sheets.
AR012
Construcció II
Pàg. 21/75
Skylights. Precast skylights.
Precast skylights placed on top of flat roofs with a metallic sheet
AR012
Construcció II
Pàg. 22/75
Skylight
On site executed skylights. This type of skylight needs special attention when it is executed and
placed on a building.
Pàg. 23/75
Typologies. Summary table
Typologies
Conventional (not inverted)
AR012
Construcció II
(cat. no invertida)
Ventilated
(cat. ventilada)
Inverted
(cat. invertida)
Green roof
Non trafficable (cat. no transitable)
Self-protected (cat. Autoprotegida)
Trafficable (cat. Transitable)
deck
Catalan roof
Improved Catalan roof (cat.catalana millorada)
Double leaf roof (cat.coberta doble full)
Non trafficable (cat. no transitable)
Trafficable (cat. transitable)
(cat. enjardinada)
Extensive (cat. extensiva)
Intensive (cat. intensiva)
Flooded roofs
Water reservoir roof -aerobic(cat. aljub -aeròbica-)
(cat. inundada)
Green roof with a water reservoir -non
aerobic(cat. aljub enjardinada -anaeròbica-)
For the traffic of vehicles
(cat. per trànsit rodat)
Conventional (not inverted) flat roof
The waterproof layer is placed on top of the insulation layer.
This layer is generally protected by the roof’s finishing layer if it’s trafficable. If the roof is not
trafficable, we must protect it or place a waterproofing self-protective layer.
AR012
Construcció II
Pàg. 24/75
CONVENTIONAL ROOF (WARM)
VENTILATED CONVENTIONAL ROOF (COLD)
AR012
Construcció II
Pàg. 25/75
Conventional. Non trafficable roofs.
Is the kind of roof which is not appropriate for the traffic of people. This type of roof is only trafficable
occasionally for the roof’s maintenance.
They are able to have different types of protective layers: self-protective waterproofing layer,
gravel, vegetation, water, etc.
An example of a roof’s solution using two
waterproofing layers and reinforcements on
the limit of the roof.
1. Formation of slopes (Cat. Formació de
endents)
2. Protection layer (cat. Capa de protecció)
3. Vapor barrier (Cat. Barrera de vapor)
4. Thermal insulation (Cat. Aïllament tèrmic)
5. Bottom waterproofing layer (cat. Làmina
inferior de la impermeabilització)
6. Top waterproofing layer, with an
incorporated protective layer against UV
rays (cat. Làmina superior de
l’impermeabilització, amb capa de protecció
contra UV incorporada)
7. Sealing and fastening element on the
end of the waterproofing layer (cat. Element
de segellat i fixació a l’extrem de la
impermeabilització)
Self-protected roof
Pàg. 26/75
AR012
Construcció II
Font: gràfic i imatge, revista TECTÓNICA
Support layer
Slope
Separating layer
Thermal insulation
Waterproofing
Structural joints
Roof joints
Protective
layer joints
AR012
Construcció II
Pàg. 27/75
Self-protected roof
With a slate layer
With an aluminum metal sheet
(cat. amb capa de pissarra)
(cat. amb làmina d’alumini gofrat
AR012
Construcció II
Pàg. 28/75
Conventional. Trafficable roofs.
•This type of roof have the finishing layer and
waterproof layer exposed. This means that both
must be designed to withstand high differential
temperatures and important fluctuations in
humidity (dry-wet cycle).
•Due to the effects produced by solar radiation,
thermal difference between day and night, low
humidity, and lack of continuous rainfall, the
durability of the waterproofing layer placed on top
of an insulation layer in warm and temperate
climates is short.
•If an insulation layer is placed on top of the
formation of slope layer, the finishing layer can
suffer from excessive deformations caused by
over-heating. It is important to place deformation
and expansion joints.
•This kind of roof can have a problem during its
execution which affects its water tightness. This is
due to a possible puncturing of the waterproof
layer during the execution of the finishing layer.
Pàg. 29/75
Conventional. Trafficable roofs.
This type of roof is characterized by having a protective layer that allows traffic, either pedestrian or
vehicular.
In the example below, the insulation is correctly placed under the slope formation layer.
Protection and finising
layer
(Cat. capes d’acabat i
protecció)
Separating layer
(cat. Capa separadora)
Waterproofing layer
(cat. Impermeabilizació)
Separating layer
Construcció II
AR012
(Cat. Capa separadora)
Slope formation layer
Structural support
(cat. Formació de pendents)
Thermal insulation
(cat. Aïllament tèrmic)
Vapor barrier
(cat. Barrera de vapor)
(cat. Suport structural)
Interior finishing
(cat. Acabat interior)
Construcció II
Pàg. 30/75
Conventional. Deck-type
A special type of conventional flat roof which has a
light support, usually made up of corrugated
metallic plates.
Common in industrial construction
The whole roof has a very light weight.
Source: table and image, TECTÓNIC magazine
Support layer
Slope
AR012
Separating layer
Thermal insulation
Waterproofing
Structural joints
Roof joints
Protective
layer joints
AR012
Construcció II
Pàg. 31/75
Conventional. Deck-type
The water tightness layer must be made up of any type of waterproof material which is
not altered by UV rays.
Pàg. 32/75
Ventilated flat roof. Catalan roofing.
Ventilated flat roof (cold roof). When using this type of roof traditionally, we have relied the water
tightness on its finishing materials. The base is made by “n” repetitions (usually n =3 or 4) of the
finishing layer placed in different directions and with steep slopes in order to prevent the direct filtration
of rainwater through the joints. This type of roof is only appropriate in warm or hot climates with
sporadic rains, due to the fact that it relies on the ventilation of its chamber and solar radiation to dry
any possible water infiltration (which can affect the interior of the building).
Catalan roofing has no waterproof layer nor insulation layer.
base with 3 layers of tiles
AR012
Construcció II
render
flashing
joists
tiling
brick filler vault
soil layer
Honeycomb bond partition
Sources:. “Com he de construir”, Benavent de Barberà. Ed. Bosch
“Diccionari de la construcció”. Miquel Fullana. Ed. Moll
AR012
Construcció II
Pàg. 33/75
Ventilated flat roof. Catalan roofing.
Pàg. 34/75
Ventilated flat roof. Improved Catalan roofing.
• The improved Catalan roofing incorporates a waterproof
layer and an insulating layer, ensuring that the roof
conforms with comfort requirements.
Construcció II
-Not necessary
Vapor barrier layer
Thermal insulation
Support
AR012
Slope
Waterproofing
Separating layer
Protection layer
Structural joints
Roof joints
Protective
layer joints
AR012
Construcció II
Pàg. 35/75
Ventilated flat roof. Improved Catalan roofing.
Ventilated flat roof. Improved Catalan roofing. Double leaf roof.
A roof that is based on the Catalan roof, applied to modern construction techniques. It was common
during the early 60’s. Usually without an insulating layer
AR012
Construcció II
Pàg. 36/75
Precast housing. Montbau. Barcelona. 1960. Casamor-Dargallo-Giralt-Serra Goday
Inverted flat roof
The waterproof layer is placed under the insulation layer. These roofs are finished with gravel,
pavements, slabs, etc. The insulating layer must have closed pores, and must be able to get wet
without altering its characteristics. These roofs thermally protect the waterproof layer in order to
achieve longer durability and tightness.
AR012
Construcció II
Pàg. 37/75
NON TRAFFICABLE
INVERTED (UPSIDE-DOWN) ROOF
TRAFFICABLE
INVERTED (UPSIDE-DOWN) ROOF
Inverted flat roof with a gravel finishing
Construcció II
Pàg. 38/75
Layer of support
Slope
Separating layer
AR012
Waterproofing
Separating layer
Thermal insulation
Protective layer
Structural joints
Roof joints
Protective
layer joints
Pàg. 39/75
Inverted flat roof with a ceramic finishing
According to some installers, the insulating layer’s tendency to
prevent heat flow into the interior of the building may create
problems of excessive deformations in the finishing layer by
causing it to over-heat
It is very important to place deformation and expansion joints.
Construcció II
Vapor barrier layer
- If the space’s hydro-thermal conditions demand it
Support
Slope
Separating layer
AR012
Waterproofing
Thermal insulation
Protective layer
Structural joints
Roof joints
Protective
layer joints
Inverted flat roof with insulation panels (Cat. Llosa aïllant)
Pàg. 40/75
AR012
Construcció II
Separating layer
Layer of support
Slope
Separating layer
Waterproofing
Separating layer
Thermal insulation
Structural joints
Roof joints
Protective
layer joints
Inverted flat roof with insulation panels (Cat. Llosa aïllant)
AR012
Construcció II
Pàg. 41/75
Trafficable upside-down flat roof
AR012
Construcció II
Pàg. 42/75
Inverted flat roof with insulation panels (Cat. Llosa aïllant). Installation
Construcció II
Pàg. 43/75
Inverted flat roof with floating flooring
ADVANTAGES:
- A ventilated chamber is created that significantly improves
the roof’s thermal behavior during summer.
- An absolutely flat surface is created which is ideal for
other uses.
- Allows many types of finishing with many different
dimensions
- If its finishing is not fixed, maintenance is done very
quickly.
AR012
DISADVANTAGES:
- During its installation phase, the finishing has to be either
protected or placed at the very last moment, this way
protecting its insulation layer (mortar layer) and then
maintenance is not so easy.
- Not fixed finishing can move if it is not well placed or
adjusted.
- Finishing with flexion resistance, not always adequate for
intense or heavy uses.
Inverted flat roof with floating flooring
(Cat. Coberta plana invertida amb paviment flotant)
Pàg. 44/75
Construcció II
Layer of support
Slope
Separating layer
Waterproofing
AR012
Separating layer
Thermal insulation
Separating layer
Protective layer: supports
Protective layer: flooring
Structural joints
Roof joints
Protective
layer joints
AR012
Construcció II
Pàg. 45/75
Inverted flat roof with floating flooring. Types of finishing.
AR012
Construcció II
Pàg. 46/75
Inverted flat roof with floating flooring. Example.
Construcció II
Pàg. 47/75
Flat green roof
(Cat. Coberta plana enjardinada)
ADVANTAGES:
- Thermal inertia: avoids the solar radiation on the surface
of the materials of the roof. It prevents over-heating. Heat
storage.
- It protects the waterproof membrane reducing its thermal
movements and increasing the roof’s useful.
- Create an additional thermo-insulating layer
- Increases acoustic insulation
- Avoids overloading drainage systems
AR012
DISADVANTAGES:
- Possibility of leaks if work is not executed perfectly (not
water tightness). It needs a good drainage.
- Greater structural requirements due to the weight the roof
has to support.
- Possible installation cost increase due to the necessity of
using waterproof layers with anti-root protection,
installations for drainage and watering installation for
intensive roofs.
Plants
Organic
substrate
Filtering fabric
Water storage
Geotextile fabric
Waterproofing
and anti-root
layer
Pàg. 48/75
Flat green roof
Layers of the System
Every 50-70m2
A – Support
B – Vapor barrier
C – Thermal insulation
D – Waterproofing layer
E – Geotextile anti-root protection
F – Storage Board
G – Geotextile layer for filtrations
Construcció II
Layer of support
Slope
Separating layer
Thermal insulation
AR012
Waterproofing
Separating layer
Protective layer: sub-base
Protective layer: substrate
Structural joints
Roof joints
Protective
layer joints
Drain
H – Substrate layer
Flat green roof. Example
AR012
Construcció II
Pàg. 49/75
Cultural facility. Les Planes de Son. Alt Àneu, Pallars Sobirà. 2002. F. Rius.
AR012
Construcció II
Pàg. 50/75
Types of green roofs
Extensive:
- Low maintenance for this type of roof
(watering not necessary) with an autorenewable natural vegetation.
- Use of sedum-type plants: resistant plants
that use a small amount of water
- Small amount of weight and thickness for
soil (10 cm approx.)
- Reduced execution and maintenance cost
- Small necessity of being exposed to the sun
- It is usually used in facilities, services, …
-Intensive:
- Roofs with a regular or intensive
maintenance.
-Gardens with perennial plants (such as
bushes, grass..)
-Very heavy and thick soil (70 cm approx.)
-Usually used for private sector roofs.
INT vs EXT
EXTENSIVE
INTENSIVE
minimum
regular / high
Vegetation
resistant, self-sufficient
Very varied, many species
Thickness
small ( low weight)
Moderate / high(very heavy)
roof protection
ecologic layer
Special gardens,
leisure spaces
Maintenance
Use
Flooded flat roof
(Cat. Coberta plana inundada)
Pàg. 51/75
Construcció II
Separating layer
Thermal insulation
Layer of support
Slope
AR012
Separating layer
Waterproofing
Protection
Structural joints
Roof joints
gràfic: REVISTA TECTONICA
Flooded flat roof. Typologies
Variant of the roof, which has an area where water is deposited with thickness not greater than 20cm. This
layer of water is a great insulation for the roof and has an important thermal mass (inertia) which provides
energy savings for the whole building.
Water reservoir aerobic roof
Water reservoir anaerobic roof
(cat. Coberta aljub aeròbica.)
(cat. Coberta aljub anaeròbica)
Water is in an open space. They may have
problems with insects and bacteria.
Water is isolated where sun light does not get to it,
therefore, bacteria does not grow in it.
AR012
Construcció II
Pàg. 52/75
Miró foundation. Palma de Mallorca. 1992. R. Moneo
Water reservoir roof
AR012
Construcció II
Pàg. 53/75
Funeral Service Building in León. León. 2000. Jordi Badia - Josep Val
Flat roof for the traffic of vehicles
Pàg. 54/75
Construcció II
Layer of support
Slope
Separating layer
Waterproofing
AR012
Separating layer
Protective layer: flooring
Structural joints
Roof joints
Protective
layer joints
Drain
AR012
Construcció II
Pàg. 55/75
Materials used for the formation of slopes
- Cellular concrete
- Concrete with lightweight aggregates (expanded
clay) for the formation of slopes. Generally with a soft
or liquid consistency and with no resistant capacity.
- Expanded clay with a mortar top layer with a
thickness of 30mm.
- Mortars with lightweight aggregates: expanded
polystyrene
- Rigid insulation boards
AR012
Construcció II
Pàg. 56/75
Process of the formation of slopes using amorphous materials
- Clean the structural support.
- Create a perimeter wall using bricks, blocks or concrete around all the perimeters, chimneys and
installation channels. Provide the placement of a deformable joint using expanded polystyrene.
- Formation of reference points marking general levels.
- Creation of screeds (cat. mestres) using mortars, small walls … for the formation of slopes falling to the
rain water evacuation elements.
-Pouring of the formation of slope material.
- If it is the case, use a thin finishing layer in order to hold the waterproof layer and not have any
puncture risks.
AR012
Construcció II
Pàg. 57/75
Improved Catalan roofing. Installation.
Example of a ceramic matchboard flooring (Cat. tauler ceramic encadellat), which has only a
support function because it will have a waterproofing layer on top.
Construcció II
Pàg. 58/75
Vapor barrier
Vapor barriers prevent the vapor present in indoor areas (warmer areas) from passing to colder areas
where water could condensate. Vapor barriers must always be placed on the roof’s warm face.
-Their placement is determined by a calculation described in CTE DB HE1 “estalvi d’energia”.
Therefore, it will depend on the hydro-thermal calculation of the roof’s section.
- This layer will prevent vapor from dissipating across the roof.
- It is very important in non-ventilated roofs and on those roofs which have the waterproofing membrane
on top of the insulating layer.
- The old regulation established that those materials whose resistance value against vapor is between
0.86 and 20 mmHgm2 day/g can be considered as vapor barriers
AR012
Example of a vapor barrier
- Polytylene sheet
(cat. Làmina de polietilè.)
- Oxyasphalt layer
(cat. Capa d’oxiasfalt.)
- Aluminum paper film
(cat. Film de paper d’alumini)
.
Bituminous waterproofing layer
Placement using hot welding: blowtorch. Heat welding of the overlapping parts of the bituminous (or
asphaltic) fabric rolls. It is fastened by adherence. As a water tightness strategy, the overlap is
indispensable.
AR012
Construcció II
Pàg. 59/75
Overlaps of the bituminous membrane
Bituminous waterproofing layer. Double coating.
The waterproof membrane has to be doubled on all the roof surface and at the points where it is folded.
(sometimes it is done three times).
Doubling the coating is done in order to ensure the general water tightness, and specially on the joints
where rolls are placed with a staggered pattern to assure greater water tightness.
This is also done on the points where waterproof layer are fold because these are weak points; points
where waterproof layers lose plasticizers because of the overheating, and points where expansion
movements can provoke the breaking of the waterproof layer first.
For this reason, when possible, the folds are made doubling the membranes and round shaped (halfpipe design).
AR012
Construcció II
Pàg. 60/75
Execution of the roof perimeters with a bituminous
membrane.
Bituminous waterproofing. Mechanical fastenings
Placement on Deck-type roofs done using mechanical fastenings. Although it is a mechanical fastening,
the bottom overlap has to be welded to the top overlap as well. Mechanical fastened layers come prepared
with a reinforced band on the area where the fastening will be done.
AR012
Construcció II
Pàg. 61/75
Overlap of bituminous layer using mechanical fastenings on top of an insulating rigid board or a wooden board.
Detail above taken from “SIPLAST”
Waterproofing. PVC.
Welding between PVC membrane with tetrahydrofuran (chemical welding) or by using hot air.
Installation process using mechanical attachments and heat-welding of the joints using a machine.
AR012
Construcció II
Pàg. 62/75
Hold the membrane
Hold the membrane to the substrate
Joint heat-welding
Waterproofing. PVC. Singular points
AR012
Construcció II
Pàg. 63/75
Execution of the roof perimeters with PVC sheets
Waterproofing. EPDM
The joints can be executed using auto-adhesive bands or synthetic rubber priming.
AR012
Construcció II
Pàg. 64/75
Placement of a large three-dimensional EPDM membrane (made at the factory using vulcanization)
Waterproofing using continuous membranes
AR012
Construcció II
Pàg. 65/75
Acrylic rubber emulsion applied using a roller
Reinforcement of the drain using a rubber emulsion
and reinfrocement
Waterproofing using continuous membranes
Polyurethane emulsion applied using pressure
AR012
Construcció II
Pàg. 66/75
Forum building. Barcelona. 2004. Herzog & De Meuron
Waterproofing using mortars
AR012
Construcció II
Pàg. 67/75
Santa Caterina Market. Barcelona. 1997-2005. EMBT
Waterproofing. Controls
Water tightness checks of the membrane in flooding situations
AR012
Construcció II
Pàg. 68/75
As a waterproofing envelope, the sheets must undergo a load test in order to ensure their complete water
tightness. The water is left between 24 and 72 hours, constantly checking that there are no water leaks. It
is best to do the testing twice:
-
The first testing once the waterproofing layer is placed
-
The second testing once all the other layers are placed on top of the waterproofing layer, when the roof
is finished.
AR012
Construcció II
Pàg. 69/75
Thermal insulation. Controls
Insulation characteristic checks:
Identification UNE 92.110
I
II
III
IV
V
VI
VII
10 12 15 20 25 30 35
On one side, we need to
check the pack’s
information (and, if
expanded polystyrene,
the brands)
On the other side, we
need to check the
correct execution:
- Layer’s continuity
- Overlap of the joints, if
it has to be done with
two layers
-Material and thickness
defined on the project.
Thermal insulations. Controls
Installation on top on the waterproofing layer
(non-hydrophilic insulation, tongue and groove,
and with a finishing layer.)
AR012
Construcció II
Pàg. 70/75
Placing around a roof’s projecting element: avoid
discontinuities in the insulating layer to avoid
creating thermal bridges.
AR012
Construcció II
Pàg. 71/75
Separating layers
Most common functions and examples:
- Permit differentiated movements between the different roof layers
- not adhered sheets
- Avoid contact between materials with chemical incompatibilities (metallic or synthetic materials)
- PVC – bituminous sheets and EPDM
- Membranes with plasticizers (Bitumen, PVC) – foam (thermal insulation)
- Metals – some types of woods
- Metals in contact (see 1st year’s class)
- Avoid adherence between different layers:
- Facilitate the drainage between the slab and the waterproofing layer
- Protect layers from puncturing:
- Waterproofing layers– formation of slope layers
- Waterproofing layers– gravel-finished layers
- Avoid plants from creating roots in the roof:
- Green roofs
- Roofs with gravel-finishing
Separating layers can be sheets; lining of products or incorporated material.
We must control that they are placed, and that they are placed in an adequate position, to avoid
compromising the durability of the roof.
AR012
Construcció II
Pàg. 72/75
Separating layers
1. GRAVEL FINISHING
1. cat. ACABAT GRAVA
2. GEO-TEXTILE FELT
2. cat. FELTRE GEOTÈXTIL
3. INSULATION
3. cat. AÏLLAMENT
4. GEO-TEXTILE FELT
4. cat. FELTRE GEOTÈXTIL
5. WATERPROOFING SHEET
5. cat. LAMINA IMPERMEABLE
6. SLOPES
6. cat. PENDENTS
Pàg. 73/75
Finishing layers
AR012
Construcció II
Most common functions and examples:
-Protect waterproofing and thermal insulation layers that can damage with the effects of
UV rays
-Loss of flexibility
-Degradation caused by plasticizer loss: cracks
-Avoid the movement of materials (due to wind suctions)
-Ballast (adding stability) of the waterproofing membrane or light insulations
-Provide an adequate surface for the use you want to give to the roof (trafficable roofs)
AR012
Construcció II
Pàg. 74/75
Finishing layers
The gravel avoids the movement of light
materials due to the wind’s suction.
Bituminous membranes, in order to be
placed on the surface of the roof, need
to be self-protected of the UV rays, by
using thin metallic sheets adhered to the
bitumen.
Pàg. 75/75
Information sources
Bibliography
Flat roof constriction Manual. Materials, designs, applications. Ed. Birkhäuser. Sedlbaure, Schunck,
Barthel, Künzel
Constructing architecture, materials processes structures.. A handbook. Ed. Birkhäuser. Andrea Deplazes.
Construction Materials Manual. Ed. Birkhäuser. Hegger, Auch-Schwelk, Fuchhs, Rosenkranz
AR012
Construcció II
Class bibliography.
CTE. Documento Básico HS. Salubridad. HS1-2.4.Cubiertas
1st year class notes: www.salle.url.edu/tecnologia
Classes de 1r curs a: www.salle.url.edu/tecnologia
Complementary bibliography. RECOMENDED
Tectónica núm. 6 (Cubiertas planas I)
Detail . Cubiertas año 2002, núm. 1
Detail . Cubiertas año 2004, núm. 4
ITEC. La coberta captadora als edificis d'habitatges
Diccionari visual de la construcció www.10.gencat.net/ptop/binaris/Dicc_cap3_tcm32-12286.pdf

flat roofs

Transcription

Similar documents