Anyone buying a second-hand house, or holding a quote for a new roof, wants to know how long it will last. We found no official Portuguese source that gives years of service life for each part of a roof. There are manufacturers’ warranties, standards that measure durability indirectly and studies on what damages a roof. This guide brings together what we read, explains why a 35-year warranty is not a 35-year roof and says what to ask the seller. We do not name contractors or give prices.
Updated on 4 November 2026. General information, not a substitute for a technician’s inspection or the manufacturer’s written conditions.
The essentials
- There is no official service-life table for tiles, sheets, membranes, gutters or timber. We did not find one at LNEC, at ADENE or in the law.
- A warranty is not a service life. A warranty says what the manufacturer pays for and under what conditions. A European technical assessment states that the “assumed working life” is not a guarantee.
- Clay tile warranties vary a lot, even within one brand: 50, 35, 30 or 10 years, or no written period at all. In the most detailed warranty we read, labour is left out.
- Salt, low slope, moss and poor flashings shorten the life of a roof and can void the warranty.
- Maintenance matters more than the number. The law asks for conservation work at least once every eight years. The industry guide asks for inspection and cleaning every year.
Warranty, durability and service life
- A warranty is a commercial promise: the manufacturer replaces or pays if a certain defect appears, within a period, if you meet its conditions. Your legal rights against the seller and the contractor are something else: see the roof works warranty.
- Durability is keeping performance over time. A doctoral thesis carried out at LNEC (2010) explains that the standard for clay tiles, NP EN 1304, assesses durability only through frost resistance. Salt, wind and moss are not part of that test.
- Service life is the time a part does its job with normal maintenance. ISO 15686-1 deals with service life planning for buildings, including the remaining life of an existing building. It gives no years per material.
An example: in a 2015 European technical assessment for a liquid-applied roof waterproofing, the German institute DIBt assumes a 25-year working life. And it writes that this cannot be interpreted as a guarantee given by the producer. It is only meant to help choose the right product.
What the sources say, part by part
| Part | What the source says | Source |
|---|---|---|
| Clay tile | 50 years (Advance Premium) and 35 years (UM and UM Canudo), from the invoice date | Umbelino Monteiro, 2025 |
| Clay tile | 35 years (Tecno, Sirius, Global, Domus, Primus, Plasma, Canudo), 30 (F3+, D3+) and 10 (F2), against frost peeling or manufacturing defects | Coelho da Silva |
| Clay tile | Bears the costs of defects; once laid, assesses case by case. No period | Cerâmica Torreense |
| Corrugated bitumen sheet | 10 years (Classic) and 15 (Tile), leaks only | Onduline Portugal |
| Under-tile sheet (subtelha) | 30 years (ST150 and ST200), leaks only | Onduline Portugal |
| Sandwich panel | EN 14509 has a durability test (Annex B). No manufacturer period read | Contents of the standard, DIN |
| Flat roof membrane | No period on the data sheet. Maintenance twice a year | Danosa, 2022 |
| Fibre cement already in place | May stay until removal or the end of its service life. No years | APA, 2024 |
| Timber structure | Rot fungi, termites and woodworm. A ventilated eave increases the timber’s durability. No years | APICER and CTCV, 2018 |
| Concrete tile (EN 490), slate, schist, metal sheet, gutters and flashings | We read no dated period | — |
How to read it:
- One brand gives different periods per model. Ask for the period of the exact model.
- Onduline’s warranties are commercial and cover only leaks, its own page says.
- At Coelho da Silva, the form is not the warranty. It has to be sent in, filled in, to receive the validated certificate.
- More on asbestos, sandwich panels and flat roofs in their own guides.
What a tile warranty does not cover
Umbelino Monteiro’s conditions (2025) are the most complete we read. They exclude, among other things:
- fitting and removal, taking off the defective tile and laying the new one;
- incorrect installation and errors in the fitting or design of the roof;
- moss or verdigris, “as a natural phenomenon”;
- weather more severe than usual, thunderstorms, floods and earthquakes;
- cleaning, water-repellent or treatment products that are not recommended;
- changes in colour or appearance.
They also require the minimum slopes (see minimum slope) and only the brand’s ceramic parts on the roof. Defects seen on delivery must be reported within 30 days, and that tile must not be laid. In the owner’s favour: the warranty passes to later owners, with no need to tell the manufacturer.
What shortens a roof’s life
- Salt, near the sea. According to the LNEC thesis, salt fog damages tiles mainly because salts crystallise inside the pores. Water-repellent tiles may last longer, but suffer more if the treated layer fails.
- Frost, only in cold and high areas. See tiles and climate.
- Moss, leaves and debris, which can damage tiles and block drainage (same thesis). See gutter cleaning and cleaning methods: aggressive cleaning also causes damage.
- Slope below the minimum and poor flashings around chimneys and walls. See flashings and joins.
- People and loads on the roof without protection.
- Damp in the timber, from old leaks or poor ventilation. See condensation in the roof void.
A maintenance rhythm
There is no legal schedule per material. What we read:
- Law: the RJUE (article 89(1), republished by Decreto-Lei n.º 108/2026) requires conservation work at least once every eight years and, at any time, the work needed for safety and health.
- Industry guide (2018): defects come mainly from lack of maintenance. It asks for a yearly routine of inspection and cleaning.
- 1998 industry manual, quoted in the LNEC thesis: ventilation and drainage every six months; general inspection, verdigris, flashings and fixings once a year.
- French guide quoted in the same thesis: light maintenance every 7 years, heavy every 15 and replacement of the covering at the end of an expected service life of 50 years. This is a foreign reference, not a Portuguese rule.
- Flat roofs (Danosa): at least twice a year, at the start of spring and autumn.
Inspect from the ground, with binoculars, and from the loft. Do not climb up: see work at height and the checklist before winter.
When the roof reaches its end
Age alone does not decide. The signs (soft or dark timber, leaks that come back, tiles crumbling in many places) and the choice between repairing and replacing are in the guide repair or replace. For the likely age of houses in your area, see building age by municipality.
When you are told “it lasts 30 years”
Ask for the answers in writing:
- Is it 30 years of warranty or of estimated service life? Who gives it: the manufacturer or the contractor?
- What is the exact model, and what is that model’s period?
- What does it cover: manufacturing defects, frost peeling, leaks only?
- Does it pay for labour and scaffolding, or only the new part?
- Does it run from the invoice or from handover of the works? Is there a certificate to request?
- What conditions must I meet: slope, the brand’s accessories, cleaning?
- Does it pass to the next owner of the house?
- And the warranty for workmanship errors? See choosing a contractor.
What we could not confirm
- Years of service life per material from an official Portuguese source. We did not find any.
- Concrete tile, slate, schist, metal sheet, sandwich panel, gutters, flashings and bitumen membranes: no dated manufacturer warranty. The RHEINZINK document (11/24) talks about durability without giving years.
- Coelho da Silva’s full certificate: we read only the request forms. The F2 period comes from the file name and a hard-to-read text.
- The dates of the pages of Onduline and Cerâmica Torreense: they do not show them.
- Insulation: we did not look for periods.
Sources (read on 4 November 2026)
- Umbelino Monteiro, warranties page and conditions Advance Premium, 50 years (PDF of February 2025) and UM, 35 years (PDF of April 2025).
- Coelho da Silva, forms: warranty requests for 35 years (PDF of 2021), 30 years and 10 years (PDF of 2018).
- Cerâmica Torreense, lusa tile, technical specifications (warranty, undated).
- Onduline Portugal, warranties and Subtelha ST200, undated.
- Danosa, Banda de reforço E 30 P Elast, data sheet, file of 2022, hosted on a third-party documentation site.
- DIBt, European Technical Assessment ETA-06/0087, 28 April 2015.
- C. Cruz, Comportamento e durabilidade de telhas cerâmicas em ambiente marítimo, doctoral thesis carried out at LNEC, University of Aveiro, 2010 (NP EN 1304, salt, maintenance, French guide).
- APICER and CTCV, Guia para Projeto e Aplicação de Telhas Cerâmicas, 2nd edition, 2018 (chapter 7).
- APA, Frequently asked questions on construction and demolition waste with asbestos, version 3.0, September 2024.
- Decreto-Lei n.º 108/2026, of 29 May, republication of the RJUE, article 89 (copy from the Ordem dos Arquitectos).
- Standards, title and scope only: ISO 15686-1:2011, Estonian standards body record; EN 14509:2013, contents published by DIN; EN 490:2011+A1:2017, SIS record.
- RHEINZINK, Information material and processing, edition 11/24.