Damp-proofing companies in Braga: what to check before you hire

Damp-proofing companies in Braga: what to check first

The Minho is one of the rainiest regions of mainland Portugal. In Braga, that means a lot of damp starts outside the house: rain driven by the wind against façades, overloaded roofs and gutters, waterlogged ground around basements.

Before hiring, check that the company looked at the outside of the house — façades, window sills, gutters, the ground — and not just the stain on the inside. A quote that only treats the inside of a wall where water is coming in from outside will probably have to be repeated the following winter.

This guide doesn't name or rate companies. Before asking for quotes, take the free diagnosis to see whether your case points to water ingress, rising damp or condensation.

Wind-driven rain: why some façades suffer more

With wind, rain stops falling vertically and is pushed against the walls. The façades most exposed to the rain-bearing winds — as a rule, those facing west and south-west — take much more water than the others. That's why it's common to see, in the same house, one dry wall and one stained wall.

• A stain that appears or grows in the days after windy storms, on an outside wall.
• Damp around windows, under the sills or next to roller-shutter boxes.
• Cracks in the external render, open joints or paint peeling only on that façade.

In these cases the treatment is usually external: repairing cracks, checking sills and drip edges, sealing the window frames, redoing the render or applying a suitable coating. Injections on the inside won't stop water coming through the façade. See the guide to water ingress.

Houses with basements: ground water, rising damp or condensation?

Many houses in the region have a fully or partly buried basement or garage, often on sloping plots. A damp basement can have three origins, and each needs a different solution.

Summer condensation surprises many people: opening the basement on a hot afternoon lets in moisture-laden air, which condenses on the cold walls. You can check with the dew point calculator and read more about basements and damp in basements and ground floors.

Historic centre and granite houses

In the centre of Braga and the older cores of its parishes there are granite masonry houses with ground floors in direct contact with the soil. Here rising damp is a real possibility, often combined with water coming through old roofs.

Ask the company how it will treat the wall after the damp-proof course and with which materials. On old walls, materials that let the wall dry out are usually preferred; ask for the justification in writing. If the house is in a protected area, check with the Câmara Municipal (city council) which rules apply to façade and roof work.

How to compare quotes for a house in Braga

In a detached house (moradia) the owner is responsible for everything — façades, roof, basement and drainage — and quotes tend to bundle several jobs into one figure. That makes them hard to compare.

1. Ask for each job on a separate line, with area (m² or linear metres) and unit price.
2. Check the order of works: as a rule, first stop the water coming in from outside, then treat the inside.
3. Ask how long you should wait between the treatment and the final plaster or paint.
4. If a quote bundles everything into a lump-sum «system», ask for the breakdown. In customer reports, these packages come in at €4,500–20,000.

As a national reference: injections or electro-osmosis €35–60/m², terrace waterproofing €28–45/m², leak detection from a few hundred euros. For perimeter drainage there are no reliable published ranges — which is exactly why you should insist on measurements and unit prices. See how much injections cost.

Quick checklist before you sign

• A valid contractor licence or certificate (alvará / certificado de empreiteiro, issued by IMPIC) in the name of whoever invoices, and the same tax number (NIF) on every document.
• A written diagnosis, with readings and with the outside inspected.
• A quote with area, unit price and what is included (plaster, painting, rubble).
• A written guarantee with conditions — including what happens if the stain returns after a rainy winter.
• No signing on the day of the visit.

The full 12 questions and the warning signs are in the guide on how to choose a damp-proofing company.

How humidade.pt works in Braga and the Minho

The diagnosis is free. If at the end you want a quote, and only with your explicit consent, your request goes to at most 2 partner companies covering your postcode — in Braga, Guimarães, Barcelos, Famalicão or another municipality in the Minho.

We require partners to hold a contractor licence or certificate, insurance and a written guarantee. They pay per request received; there is no paid placement or bought prominence. Find out more in how we make money or, if you're a company in the region, in for companies. Already have a quote? Ask for a second opinion.