Anyone about to have roof work done wants to know three things: when is best, what to prepare and what will happen at home. This guide puts the job in order: choosing the time, what to do beforehand, who deals with the rubble, the steps of the work and what to keep at the end. We say what has a source and what is our own advice. We do not name firms or give prices, and we found no source for the typical duration of a roof job.
Updated on 3 November 2026. General information, not a substitute for the contract or a technician.
The essentials
- July and August are the driest months at the four IPMA stations we read. But heat also weighs on the people working.
- With rain or strong wind, the work stops. The law only allows work at height when the weather does not endanger safety (Decreto-Lei n.º 50/2005, article 36, no. 8).
- The rubble is the responsibility of whoever is named as producer. It belongs in the contract. Responsibility only ends when the waste reaches a licensed operator.
- Ask the town hall for the scaffold on the street in good time. In one municipality we read (Estarreja), you apply at least 10 working days ahead.
- At the end, keep photographs, the invoice, the warranty and proof for the rubble.
When to do the work
IPMA publishes the 1991 to 2020 normals by station. This is a summary of July and November (days with 1 mm of rain or more):
| Station | July | November |
|---|---|---|
| Porto (Pedras Rubras) | 16.6 mm, 3.1 days | 165.9 mm, 13.0 days |
| Lisbon (Gago Coutinho) | 2.9 mm, 0.4 days | 114.6 mm, 9.3 days |
| Évora | 2.7 mm, 0.6 days | 86.0 mm, 8.8 days |
| Faro | 0.9 mm, 0.2 days | 75.5 mm, 6.6 days |
At all four, July and August are the two driest months, and October to December are among the wettest. Heat counts too: in Évora there are, on average, 11.5 days in July and 10.9 in August with a maximum of 35 °C or more (Lisbon 2.5 and 2.8; Porto 0.6 and 0.8). We found no official temperature limit for work on roofs.
Our conclusion, with no specific source: plan the work to finish before the October rains, because an open roof in winter is the risk to avoid. See the checklist before winter. If the roof is already damaged, see the first 48 hours: urgency comes before the calendar.
If the weather changes halfway
IPMA issues warnings by district, for strong wind, heavy rain, heat and others, in yellow, orange and red, looking 72 hours ahead. Before signing, ask the contractor how the open part of the roof is covered at the end of each day and who decides to stop. The APICER and CTCV guide lists, among the cares of a rehabilitation, «specific climatic or protection conditions» for the work. For the safety law, see the guide to work at height.
Before the work
- Diagnosis. The APICER and CTCV guide describes inspecting from outside and from inside the roof space, after gathering the building’s history. Ask for it in writing. For the quote, use the checker and the cost guide.
- Who does it. See how to choose the contractor and the checker.
- Permit. Repair is usually exempt, but changing material, colour or shape may need a procedure: see the works permit. In a historic area, see the heritage guide.
- Scaffold and street. In Estarreja, the licence to occupy the public road for works, with hoardings and scaffolding, is requested 10 working days ahead and the decision comes within 10 working days, once the request is properly filled in. Each municipality has its own regulation and fee: ask yours.
- Protect the inside (our advice): clear the loft and the top floor, cover furniture and ask for a plan for dust and for rain.
- Photograph the starting state. If the cause was a storm, the damage file helps organise photographs and costs.
Rubble: who handles it and how
The Portuguese Environment Agency (APA) explains, in its frequently asked questions on construction and demolition waste, that the regime is in Decreto-Lei n.º 102-D/2020, as currently worded. In short:
- Who is the producer should be set out in the contract between client, contractor and subcontractors.
- Responsibility only ends when the waste is handed to licensed treatment operators.
- Sorting on site is mandatory, at least for wood, mineral fraction (including tiles and ceramics), metal, glass, plastic and plaster.
- All transport carries an electronic waste guide (e-GAR), with no exceptions. Ask for the codes and the proof of receipt. APA has a public search for licensed operators.
- An owner who repairs their own home (small repairs) hands the waste to the municipality or the recycling centre.
- In works subject to the RJUE, the producer must keep the construction-waste data record with the site logbook. Cleaning at the end is a condition for the occupancy licence.
If the roof is fibre-cement, special rules apply: see the asbestos guide.
How the job goes
This order sums up the «twenty guidelines» and the rehabilitation strategies of the APICER and CTCV guide. It is not a timetable.
- Erecting the scaffold and protection.
- Lifting the tiles and setting aside those that can be reused.
- Structure: check rafters, battens and purlins, and replace what is rotten. Battens must be aligned, without warping.
- Watertightness and ventilation: an under-tile layer or breathable membrane, where planned, and ventilation under the tile.
- Tiles with the model’s fixings (the canudo needs corrosion-resistant clips), watertight and ventilated ridges and hips, as little mortar as possible.
- Flashings: chimneys, valleys and eaves.
- Gutters and downpipes.
- Cleaning and removal of rubble.
At the end of the job
- Photographs of the roof, the flashings and what is now hidden.
- Invoice with the firm’s details. See VAT on works.
- Written warranty: see the works warranty.
- Proof for the rubble and, if there was a procedure, the Câmara’s reply.
- Annual routine: APICER and CTCV recommend an inspection and cleaning every year. See gutter cleaning.
What we could not confirm
- The typical duration of a roof job: there is no source.
- Official temperature limits for work on roofs.
- The rules of each municipality for scaffolding and skips; Estarreja’s deadline is only an example.
- Whether a waste management plan is required for small private works. We read that it is mandatory for public works.
- Whether your job needs an e-GAR issued by you: APA says transport always carries an e-GAR, without saying who issues it.
Sources (read on 3 November 2026)
- IPMA, 1991-2020 climate normals (Porto, Pedras Rubras, Lisbon, Gago Coutinho, Évora, Faro).
- IPMA, Guide to weather warnings.
- APA, Frequently asked questions, construction and demolition waste, version 4.0, June 2025 (Decreto-Lei n.º 102-D/2020: full text not read).
- Câmara Municipal de Estarreja, Licence to occupy the public road for works.
- APICER and CTCV, Guia para Projeto e Aplicação de Telhas Cerâmicas, 2018 (inspection, execution steps, annual maintenance).
- Decreto-Lei n.º 50/2005, article 36, no. 8, as read in our work at height guide.