Glossary

Glossary

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Accessories (for roofs)

Complementary pieces for roofing.

Argil

Formed through the disaggregation of feldspar rock that becomes malleable when wet. Argil can be found near riverbeds, often forming banks along the margins. Argil can be white, red, gray and brown. It is composed mostly of hydrated alumina sillicata - - Al2O3 · 2 SiO2 · 2 H2O, has low cristallinity and minute dimensions (particles under 2 µm in diameter). Mineralogically, its main components are quartz, illite, caulinite, anatase, hematite and feldspar.

Break

Same as fracture.

Clay tiles

Products for non-continuous application on inclined roofs and wall linings, made by standardizing processes (extrusion and/ or pressing), drying and baking prepared argil, with or without additives.

Construction products

Products to be used or applied permanently in construction projects.

Coverage

of composing elements (roof tiles and accessories)

Crack

Structural defect that consists of a gap with a more or less regular shape affecting the thickness of the piece and is visible to the naked eye.

Distance between laths or gauge

Length of the exposed part of a roof tile or accessory, measured longitudinally.

Eave

Edge of a roof along the outer part of a protruding roof slope, made of roof tiles

Eaves

Edges of a roof along the outer part of a roof slope, projecting beyond the side of a building and composed of accessory pieces.

Effect of ice

This term refers to the wear caused on roofing pieces by successive frost-defrost cycles.

Engobe

Type of coating, permeable or impermeable, or the material used therefore.

Extrusion

Production process.

Fissure

Crack with a more or less regular shape that does not affect the whole thickness of a piece.

Fixation orifice

Open or easily pierced orifice for the fixation of a product on the support structure.

Fracture

Structural defect that consists on the breaking of a product into two or more fragments.

Garrett

Space under a roof slope

Gutter / Joist

Concave, open piece, usually made of metal, through which liquids run, placed horizontally along the eaves of a roof to drain rainwater, thus avoiding infiltrations.

Hygroscopy

Property of materials relating to their capacity to absorb water. Ceramic materials are less hygroscopic than concrete or mortar.

Lath

Secondary structural piece of a roof arranged in a perpendicular line in relation to the highest inclination of a roof slope, where coating elements are supported.

Linearity

When used in relation to flat or fitting roof tiles, the value of linearity is given by the deviation in a straight line as measured from the roof tile brim, both longitudinally and transversally.
For Canudo roof tiles, linearity is given by the deviation in a straight line as measured along the generating line at the bottom of a roof tile’s concave end.

Mechanical resistance to flexion

This test is conducted by applying an increasing force on a roof tile until it breaks. The value registered at the breaking point indicates the flexion of the roof tile.

Outeiro da Cabeça

Village located 18 Km from Torres Vedras.
The village covers an area of 5,7 Km2 and has a population of 932 inhabitants. Its main economical activities revolve around red clay ceramic industries (roof tiles and bricks) and agriculture.

PDM

 PDM: Municipal Master Plans (Portuguese).

Pre-hole

Fixation orifice that is not fully pierced through.

Recommended overlap

Roof tile length that must be overlapped to the next roof tile.

Roofing functional demands

Minimum criteria to be met by a roof. The proper performance of any roof depends on three main factors: correct conception at the project stage, good individual performance of clay pieces and their correct application on the roof.

Roof slopes

Where joists are placed.

Roof tile fixation

Use of nails, screws, metal hooks or any other auxiliary fixation mechanisms that prevent pieces from moving.

Roof tile gap

Gauge or distance between laths.

Slope

Also known as pitch or roof surface; any flat surface of an inclined roof.

Splinter

Surface defect over 7mm on average, consisting of a fraction of the material, separated from the ceramic body on the visible side of the product.

Support spindle

Relief at the underside of a roof tile or accessory allowing its fixation on the support structure, generally consisting of laths.

Tone

Colour shade variation on the same make of pieces.

Transversal profiles

This term is applied to Canudo roof tiles and refers to the width of its internal edges.

Underside roof tile ventilation

Also known as micro-ventilation; this refers to the circulation of air near the underside of a roof tile. Aids in the drying of absorbed rainwater and eliminating water vapour from inside a building, which could otherwise condensate on the underside of the roof tile; also aids in the conservation of the lath work, when it is made of wood. Improves roof tile resistance to the effect of ice.

Ventilation

Air circulation process.

Watertight

In this context, the term relates to the capacity of a roof to completely prevent the entry of water. Impermeability of the clay material used and total roof coverage must be ensured, as well as the correct inclination of the roof. Wind and rain, which in conjunction can provoke ascending water movement along the roof surface, are a serious challenge to the watertight qualities of a roof.

Specifications

All technical information in one, single place.

Technical characteristics

 
Weight (1)3,800 Kg3,350 Kg3,800 Kg
Lath spacing (1)38,5 cm38,0 cm38,5 cm
Length (1)46,5 cm45,5 cm46,5 cm
Width (1)27,0 cm26,5 cm27,0 cm
Units per m211,51211,5
Units per mini-parcel (2)-6-
Units per pallet (2290300300
Weight per pallet1.120 Kg1.030 Kg1.160 Kg
Reference weight per m243,7 Kg40,2 Kg43,7 Kg

(1) Average values. Due to the characteristics of ceramic materials, slight variations in size and tonality may occur. This is a normal result of the fabrication process and such variations are to be expected. The weight and measurement values presented here are merely indicative and should be confirmed on site.
(2) Amounts for standard parcels

Observation: values presented applicable only to tiles of natural colour; these can be changed without prior notice. The recommended minimum slopes should be consulted on the respective page. For more information, please contact our Sales Department.

Inclination of the roof slope

The meticulous definition of the inclination of a roof slope always requires the consultation of two fundamental elements:

  • Table of recommended slopes by product type
  • Map of the national territory, with the definition of the climatic zones

Lusa roof tile: Minimum recommended inclination (%)

Any tile type can be used on a sloping roof. However, the maker cannot be held responsible in the case of failure to comply with the technical specifications resulting in defective performance.

When roof inclination is lower than recommended, supplementary insulation elements should be used to guarantee the roofing work is properly watertight.

Application Manual

SlopeSituationZone 1Zone 2Zone 3
< 6 mprotected212530
normal232833
exposed273338
6 - 10 mprotected232833
normal263137
exposed303642
> 10 mprotected253036
normal283440
exposed333946

The values above are applicable to roofing work executed without inner lining. For roofing work with lining, these values can be reduced by 1/7 (ref. DTU 40.21).

Climate Zoning by joint wind
and precipitation values

Climate Zoning by joint wind
and precipitation values

Technical performance telha Lusa:
norm/functional demand

Physical and mechanical characteristicsSpecification
Flex resistance1.200 NExceedsExceedsExceeds
Coef. of impermeability
(Method 2 – Level 1)
Min. ≤ 0,85
Average ≤ 0,80
To StandardTo StandardTo Standard
Resistance to frost (C Method)50 CyclesExceedsExceedsExceeds
Geometrical characteristics
Coef. of planarity (%)≤ 1,5To StandardTo StandardTo Standard
Rectilinearity (%)≤ 1,5To StandardTo StandardTo Standard
Dimensional stability
Length (%)±2To StandardTo StandardTo Standard
Width (%)±2To StandardTo StandardTo Standard

Observation: values presented applicable only to tiles of natural colour; these can be changed without prior notice. For more information, please contact our Sales Department.

Quality Guarantee Terms

Cerâmica Torreense takes full responsibility for the expenses resulting from product faults, as long as they are applied according to the instructions described in the “Ceramic Roof Tiles Application Manual”, edited by APICER (Portuguese Ceramic Industry Association).
 

By “full responsibility for the expenses”, we mean:

  1. The replacement of faulty parts when defects have been detected before applying the product in place, such as warps, breaks or shades. Should this be the case, the constructor must separate these parts and quickly contact Cerâmica Torreense or the supplying company.
    Attention: After its application in place, the product will not be considered faulty when it comes to defects which were visible and detectable prior to being applied in place, such as those above mentioned.
  2. The replacement of faulty parts on site and the costs inherent to their replacement on the roof, in case the detection of faults occurred after the products had been put in place, as long as those defects were not detectable prior to being applied on the roof. Only those cases concerning joint and exclusive application of roof tiles and accessories with Torreense make are taken into consideration.

The faults covered are those which make the product non-conforming with the terms defined in the European norm for ceramic roof tiles certification – NP EN 1304 – in force at the date of manufacture.

Cerâmica Torreense recommends the use of non hydrofuge products and joint assembly of roof tiles and accessories of the same brand.

In case of hydrofuge products, the full range of expenses covered by the above mentioned line a) applies, i.e., all the faults detected before applying them in place. Those cases covered by line b) will be duly assessed.