FACTORS AFFECTING THE SELECTION OF
Roofing tiles are used to cover sloping roofs.
Supported on wooden reapers or light gauge steel
or steed rods are also used.
Normally these tiles are having curved surface
having ribbed sections, so that with thin section
they are sufficiently strong to resist the load.
Some times flat tiles are used under
1. They should not absorb moisture more than
20 per cent by weight.
2. They should give pleasing look.
3. They should be capable of taking load of a
man safely, after they are supported on
4. They should be durable.
5. They should be uniform in shape and size.
6. warpage should not exceed 2% along the
edges and 1.5% along the diagonal.
Type of building
Type of framework
Appearance and special features of locality
Availability of material
Climate of locality
• Extremely low water absorption
index, less than 0.4%, which makes its
resistant to frost damage.
• Consists of bituminous slates called
eternit (generic term for fiber cement).
• Available in three colours-grey,black and
• SIZE- 12’’x6’’, 6mm thickness
• COST- 25-30/Sq.ft
Slates are obtained from quarries as
Reduced to slabs after dividing into
sections using diamond or circular saw.
Each slab is divided into thin laminate
or slate by using splitters
Slates roofs tiles are usually
fixed either with nails or
Fixing is typically with
double nails onto timber
battens or nailed direclty
onto timbersarking boards.
nails are made up of alloy
and stainless steel.
• Laid such that each slate
overlaps a slate in the next
course below it.
• Two holes are made from
the bed of the slab at the
centre or head so
• Slates are fixed to battens
by copper or zinc nails.
• The spacing of battens
i.e,gauge is determined as
gauge=(length of slatelap)/2
• A layer of felt is used
below slate to exclude rain
water and moisture.
• Allahabad tiles are generally laid side by side and the joints are
covered with half round tiles.
• It consists of flat broad bottom undertile that alternate with
convex curved overtile.
• Unfertile is flat,tapered,with flanges at the side.
• The overtile is half round and tapered in plan with diameter
tapering from 16 cm at tail to 12 cm at the head.
• The taper in the overtile allow the tile in next course to fit in.
• Vertical battens of size 2.2cmx7.5cm are fixed between sides
of adjacent undertiles and to these half round overtiles.
• Overtiles are fixed to vertical battens with 75 mm nails.
• Cost- 55-145 Sq.ft
Clay roofing tile is a good choice for homes with a
southwestern, Italian, or Spanish Mission design, or
even for homes with a modern, clean look.
Tile lasts a long time
Burnt clay tile roofs are only used for sloping roofs
between about 20° and 50° inclination of rafter.
Clay tiles are heavy, requiring a strong substructure
and closely spaced battens.
Tile won't rot or burn, and it
can't be harmed by insects.
The color of a clay tile is not
affected by exposure to the
elements, it can easily last for
A major problem of clay tiles is the
immense loss due to cracking and
Clay tile production is a traditional
village craft in many regions, but
uniform shapes and qualities are
difficult to achieve.
Special properties- Durable, waterproof
cladding for sloped roofs
Economical aspects -Low to medium costs
Resistance to earthquake- Low
Resistance to hurricane- Medium to good
Resistance to rain- Very good
Resistance to insects -Very good
Climatic suitability- All climates, but most
common in humid areas
PROCESS USED TO CREATE
OBJECTS OF A FIXED, CROSSSECTIONAL PROFILE
Burnt clay tiles requires
inspections at least twice a year
so as to last for further years.
They often develop cracks with
A cracked tile needs to be
replaced or repaired in place.
Mix up a small amount of mortar
and carefully fill in the crack. Be
sure to wet the tile with plenty of
water to help the mortar set up
Tiles will be slippery when wet
Plain tiles, pantiles, Roman
tiles, interlocking tiles, and
ridge, hip and valley tiles are
made of this material.
The mixture is composed of
normal Portland cement and
clean well-graded sand.
The body treated with mineral
granules which have been
coated with color.
Durability estimates range from 30 to 50
Weigh between 9 1/2 and 12 pounds(1
pound =.45 gram) per square foot.
Size is 265mm by 165 mm and 12mm thick.
Require low maintenance
Offer good fire protection and are
resistant to rot and insects.
INR 150 to INR 300/ Sq.ft
The usual lap for plain tiling is 65mm, for pitched roof at 37
For pitches up to 60 degree the tiles should be twice nailed
in every third course to once nailed in each course.
For pitches exceeding 60 degree all tiles should be nailed
The nails are usually 38 mm long and may be either
galvanized wrought iron, zinc, copper or composition.
PROCESS USED TO CREATE OBJECTS OF A
FIXED, CROSS-SECTIONAL PROFILE