# Roof tile types and climate in Portugal: frost, salt, wind, heat and snow

> The five clay tile formats (lusa, marselha, canudo, romana, plana), what the climate asks of each tile and the questions to ask before buying. With a quick check by zone.

- Page: https://telhadoseguro.pt/en/guides/roof-tiles-by-climate
- Language: English
- Updated: 2026-11-02

## Summary

- There are five clay tile formats in Portugal: lusa, marselha, canudo, romana and plana, with different weights and sizes.
- The climate asks different things: frost resistance inland, low absorption on the coast, fixing in windy places, light colour and ventilation in the heat.
- Since 2017 clay tiles have three frost resistance classes (30 to over 150 cycles). Ask for the class.
- There is no single minimum slope: it depends on the model, the climate and the exposure, and is in the manufacturer data sheet.

In Portugal almost every house with a pitched roof uses ceramic tiles, but the climate is not the same from Bragança to Faro, or in the mountains and on the beach. The same tile model can last decades in one place and flake off within a few winters in another. This guide explains the types of tile that exist, what the climate demands (rain, frost, salt, wind, heat, snow) and the right questions to ask before you buy. We do not name "the best tile for each municipality": no official source says so, and we say where data is missing.

*Updated on 2 November 2026. General technical information. It does not replace a technician's design or the manufacturer's data sheet.*

## The essentials

- **Ceramic tiles sold in Portugal come in five formats:** lusa, marselha, canudo (half-round barrel tile), romana and plana. They differ in weight, size, interlocking and the number of tiles per square metre.
- **Different climates ask different things of the tile:** resistance to **frost** in the cold interior, low absorption and **salt** resistance on the coast, **fixing** in windy areas, **light colour and ventilation** in the heat.
- **Frost resistance is measured:** since 2017, clay tiles for outdoor use have three frost-resistance classes, from 30 to more than 150 freeze-thaw cycles. Ask for the class.
- **The canudo tile needs fixing with clips.** Without them it slides, especially on a steep pitch or in strong wind.
- **There is no single minimum pitch.** It depends on the model, the climate and the exposure. It is in the manufacturer's data sheet, not in a general rule.
- **The roof works as a system:** pitch, ventilation under the tile, flashings and fixings matter as much as the tile.

## The five ceramic tile formats

The *Guia para Projeto e Aplicação de Telhas Cerâmicas* (Guide for the Design and Application of Ceramic Tiles; APICER (Portuguese ceramics industry association) and CTCV (ceramics and glass technology centre), 2018) divides commercial tiles into: **flange-and-barrel tile** (lusa and romana), **interlocking flat tile** (marselha and plana) and **tile without interlocking** (canudo). Average values from the guide:

| Format | Weight per tile | Length × width | Batten spacing | Tiles per m² |
|---|---|---|---|---|
| Lusa | 3.0 to 4.0 kg | 42 to 48 × 23 to 30 cm | 36 to 42 cm | 10 to 14 |
| Marselha | 3.2 to 4.0 kg | 42 to 47 × 23 to 27 cm | 32 to 40 cm | 10 to 12 |
| Canudo | 1.6 to 2.5 kg | 40 to 47 × 12 to 22 cm | 30 to 40 cm | 22 to 35 |
| Romana | 1.8 to 4.0 kg | 40 to 57 × 12 to 20 cm | 25 to 46 cm | 18 to 35 |
| Plana | 3.5 to 4.6 kg | 42 to 50 × 25 to 30 cm | 37 to 39 cm | 11 to 13 |

What this means in practice:

- **More tiles per m²** (canudo, romana) means more pieces and more joints to watch, but lighter tiles.
- **The values are ranges of "average characteristics"** for the market. A specific manufacturer has its own: check the model's data sheet.
- **The name changes from region to region.** The guide itself warns that Portuguese terminology varies depending on the part of the country, including for accessories.

## The climate of Portugal in a few lines

According to the Instituto Português do Mar e da Atmosfera (IPMA, the Portuguese Institute for Sea and Atmosphere), most of mainland Portugal has a temperate climate of type **Cs** (dry summer), with two varieties in the Köppen classification:

- **Csa**, hot and dry summer: the inland Douro valley (part of the district of Bragança) and the areas south of the Montejunto-Estrela system, except the west coast of the Alentejo and the Algarve.
- **Csb**, dry and mild summer: almost all of the territory north of the Montejunto-Estrela system, the west coast of the Alentejo and the Algarve.

IPMA says this classification uses the 1971 to 2000 normals. For cold and frost, IPMA publishes in the 1991-2020 normals the variable "average number of days with a minimum temperature equal to or below 0 °C", by weather station. **Check the station closest to your home**: frost changes a lot with altitude and with the valley.

## Five hazards and what to do about the tile

### 1. Rain: the tile is not enough

Waterproofing comes from the clay and the firing. But the APICER and CTCV guide is clear: **"the waterproofness of the tiles is not the only guarantee of watertightness"**. The pitch and the correct installation of the tiles and accessories (ridge tiles, hips and valleys, flashings) make the difference. In its list of the most common defects, the guide points to **excessive or insufficient pitch** and **insufficient drainage** (low pitch and small gutters) as design problems.

### 2. Frost: ask for the class

In cold regions the wet tile freezes and thaws many times, and the water that freezes inside the tile can make it flake. Commission Delegated Regulation (EU) 2017/1475, of 26 January 2017, created three frost-resistance classes for clay tiles for outdoor use (EN 1304), according to the test in EN 539-2:

| Class | Freeze-thaw cycles without unacceptable damage |
|---|---|
| 1 | 150 or more |
| 2 | 90 to 149 |
| 3 | 30 to 89 |

The APICER guide adds two measures against frost: **ventilate the underside of the tile well** and **a steeper pitch**. And it says to replace a tile that flakes, because it does not recover. **Ask the supplier for the declared frost class** and ask for the declaration of performance.

### 3. Salt and the coast

In coastal areas the tiles are exposed to a **salt-laden environment**. The guide explains that flaking can come from frost **or from salt**, because water or chlorides crystallise under the surface and detach it. To reduce the risk it recommends a tile with **proven freeze-thaw resistance and low water absorption**. The guide also reminds us that tiles are exposed to the cleaning agents used in maintenance: check the product before cleaning.

### 4. Wind

Wind lifts pieces at the **ridges, hips and edges**. The guide says that **mechanical fixings, in the number and form recommended by the manufacturer**, may be needed, and that there are tiles with support lugs or fixing holes, plus reinforcement clips.

Two cases that the guide highlights:

- **Canudo tile.** It needs regular fixing, with corrosion-resistant clips, or it may slide. With a steep pitch or strong wind, it calls for **stronger clips attached to the battens by nail or ring, at least every four courses**. In the most critical situations, fix all the clips or screw the tiles down.
- **Mortar.** It should be avoided in the main field of the roof, at ridges and at hips: it adds weight, moves differently from the tile and makes maintenance harder.

### 5. Heat and sun

The **solar reflectance** of the tile matters in summer. The guide explains that tiles with a higher reflectance index heat up less and let less heat into the building, and that **lighter tiles usually reflect more**. Heat gains are also reduced by **roof insulation** and by **natural ventilation of the underside** of the tiles.

### What about snow?

The guide notes that snow calls for steeper pitches, to avoid loads that compromise the structure, and that ceramic tile has the mechanical strength for distributed loads such as snow. **The snow load values by zone and altitude are in Eurocode 1 and its National Annex**, which we have not read: ask the designer.

## Minimum pitch: the honest answer

We looked for an official table of minimum pitch by tile type and did not find one in a Portuguese source that we could read. This is what we know:

- The APICER and CTCV guide **does not give a value**. It says the roof should have "a pitch suited to the location and to the severity of the local climate" and, as far as possible, similar to that of the surrounding buildings.
- By the guide's convention, a **pitched roof** is one with a pitch **above 8%** (about 4.5°). Below that it is a flat roof, with other rules.
- Manufacturers publish **pitch tables** by model, which depend on the climate and the exposure. **We do not repeat numbers from unverified sources**: forums, calculators and foreign catalogues give values that differ from one another.

**What to do:** ask the contractor for the model's data sheet with the minimum pitch for your area and exposure, and confirm that the roof complies.

## And insulation? The rule by climate zone

Portaria n.º 138-I/2021, of 1 July (a ministerial order), sets minimum insulation requirements. For **housing on the mainland, new or renovated buildings** (the text of the portaria defines what counts as renovation: ask the technician whether your work qualifies), the maximum thermal transmittance coefficient of the **horizontal elements of the exterior envelope** is:

| Winter climate zone | I1 | I2 | I3 |
|---|---|---|---|
| Maximum U (W/m²·°C) | 0.40 | 0.35 | 0.30 |

The zone (I1, I2 or I3) depends on the municipality: **we did not find the list of municipalities by zone** in a source that we could read, so tell the technician your municipality and ask for the zone. See also the [aid for insulating the roof](https://telhadoseguro.pt/en/guides/roof-insulation-aid).

## What about concrete, slate, metal and sandwich panel?

Each has its own standards and data sheets (for example EN 490 for concrete tile and EN 14509 for sandwich panels). **We do not compare the climate performance of these materials**, because we did not find official sources or dated data sheets from Portuguese manufacturers that allow it. If you are thinking of changing material, ask the contractor for the declaration of performance and the data sheet, and check whether the change needs a procedure at the câmara municipal (town council) (see the [guide to the works permit for roofs](https://telhadoseguro.pt/en/guides/roof-works-permit-2026)).

## Questions to ask before you buy

1. Does the tile have **CE marking** and a declaration of performance under EN 1304 (ceramics)?
2. What is the declared **frost-resistance class** (1, 2 or 3)?
3. What is the **water absorption** (important on the coast)?
4. What is the model's **minimum pitch** for my area and exposure?
5. How will the **fixing** be done (number of tiles fixed, clips, ridges and hips dry-fixed or with mortar)?
6. Is there **ventilation under the tile** and at the ridges and eaves?
7. What **underlay, flashings and finishing details** are planned?
8. What is the **weight per m²**, and can the structure take it (important if you are changing material)?
9. Is the tile **light in colour** and will it go with insulation? (important in the south)

Ask for everything in writing in the quote (see the [guide to VAT on roof works](https://telhadoseguro.pt/en/guides/roof-works-vat) for the invoice).

## What we could not confirm

- **Minimum pitch by tile type.** There is no value in the APICER and CTCV guide, and the manufacturers' data sheets that we found were not accessible or were foreign.
- **Wind and snow zones** from Eurocode 1 and the National Annex (and the former RSA), by municipality and altitude.
- **Frost days by locality.** IPMA has the data in the 1991-2020 normals, but only as an interactive map, with no table that we could read.
- **Climate zone (I1, I2, I3) of each municipality.**
- **Climate performance of concrete, slate, metal and sandwich.**
- **Prices.** We do not give them without a dated source.

## Sources (read on 2 November 2026)

- APICER and CTCV, [Guia para Projeto e Aplicação de Telhas Cerâmicas](https://www.apicer.pt/apicer/media/5c06bd0e8d436.pdf), 2018 (formats and average values, frost, salt, wind, fixing, solar reflectance, most common defects).
- Commission Delegated Regulation (EU) 2017/1475, of 26 January 2017, [Regulamento Delegado (UE) 2017/1475 da Comissão, texto no legislation.gov.uk](https://www.legislation.gov.uk/eur/2017/1475/data.html) (frost-resistance classes for clay tiles).
- IPMA, [Normais climatológicas, classificação do clima](https://www.ipma.pt/pt/oclima/normais.clima/) (Köppen, Csa and Csb; variable for days with a minimum temperature ≤ 0 °C in the 1991-2020 normals).
- Portaria n.º 138-I/2021, of 1 July, Diário da República (official gazette), 1st series, no. 126 (table of maximum U; read in an excerpt reproduced in a PDF, not on the official gazette's site).
- EN 1304, EN 539-2, EN 490 and EN 14509: cited through the sources above and third-party data sheets; the standards themselves were not read.

## FAQ

### Which tile is best for my climate?

No official source names the best tile per municipality. The guide shows what each climate asks (frost, salt, wind, heat, snow) and the questions to put to the supplier.

### What is the frost resistance class?

Since 2017 clay tiles for outdoor use have three classes: 1 (150 cycles or more), 2 (90 to 149) and 3 (30 to 89 freeze-thaw cycles without unacceptable damage).

### Do canudo tiles need fixing?

Yes. The APICER and CTCV guide says they need regular fixing with corrosion-resistant clips, reinforced with a steep slope or strong wind.

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Source: https://telhadoseguro.pt/en/guides/roof-tiles-by-climate. Independent information, not legal or tax advice.