Damp Proofing Costa Blanca

What is included

Damp Proofing, Start to Finish

From the survey through to the wall being replastered and decorated, by one firm.

Why here

Why Damp Problems Are Common on the Costa Blanca

Plenty of sunshine does not make a property immune from damp.

It is not that the air here is unusually wet. AEMET, the Spanish state meteorological agency, records a mean relative humidity of 66% across the year at its Alicante station, rising to 69–70% through September, October and November. Plenty of northern European homes sit in damper air than that.

What matters is what the moisture in that air meets. Spanish masonry is heavy, largely uninsulated and slow to warm up, so internal surfaces stay cooler than the air around them — and a cool surface is where airborne moisture condenses out. Add a property shut up for weeks at a time with no ventilation, and the autumn peak above arrives in a building with nothing to stop it.

Construction matters just as much. Many older Spanish properties were built quite differently from a modern British house. A traditional finca may have thick masonry or stone walls with no cavity and no damp proof course at all. Villas and town houses often have ground-floor walls, underbuilds or retaining walls sitting in direct contact with the surrounding soil.

Then there is everything that lets water in from outside: cracked rendering, waterproofing that has reached the end of its life, roof defects, terraces over habitable rooms, and joints that were sealed once and never looked at again.

Which is the long way of saying that identifying the source is the first stage of treating damp, not an optional extra before the real work starts.

Hillside plots

Lateral Damp and Retaining Walls

Water does not only travel upwards.

Lateral damp matters here because so much Costa Blanca property is built into a hillside or on a sloping plot. Instead of rising, water penetrates sideways through a wall that has soil or rock against the other side of it.

It affects underbuilds, basements, garages, lower floors, retaining walls, hillside villas and fincas cut into a terrace. The wall can look completely sound from inside while water is standing against its buried face.

What can be done depends heavily on access and on how the wall was built. The options include applied waterproofing systems, tanking from the inside, improving drainage so water is taken away from the wall in the first place, and remedial finishes once the wall is protected.

Where the buried face can be exposed, treating it from outside is usually the stronger answer. Where it cannot, tanking the inside is the practical one.

Town houses

Town House Damp Proofing

Party walls, enclosed rooms and very little through ventilation.

The old town houses in villages across this part of the coast have their own moisture problems, and they are rarely the same as a villa's.

Shared party walls, rooms with only one external wall, ground floors that sit below the level of the street outside, and construction that predates any idea of a damp proof course all play a part. Add a property that is shut up for parts of the year and condensation joins in too.

The problems we get called to look at are usually some combination of damp at floor level, black mould, peeling paint, blown plaster, a musty smell, walls that feel cold or actually wet to the touch, damp patches that appear after rainfall, and moisture tracking around the external walls.

Once we have a view on where it is coming from, we can recommend a treatment — instead of repainting the same wall every spring.

Penetrating damp

Penetrating Damp

If it gets worse after heavy rain, water is getting in from outside.

That one observation — the patch grows after rain — separates penetrating damp from nearly everything else, and it is the first thing we ask about.

The way in might be cracked exterior render, damaged external walls, a roof defect, failed flashing, a leaking terrace, a window or door that was never properly sealed, defective guttering or drainage, or a waterproof membrane that has simply come to the end of its life.

Finding the entry point is the whole job, because water travels. The damp showing on the inside face of a wall is often nowhere near the defect that let it in — it can run down a cavity, along a beam or across a slab before it appears. Treating the visible patch and ignoring the entry point is why some damp problems keep coming back in a slightly different place each year.

Flat roofs

Flat Roof Waterproofing

Flat and low-pitched roofs rely entirely on their waterproof layer. There is no pitch to help, so when that layer goes, water goes in.

Cracking, membranes that have aged and gone brittle, outlets that were never sealed properly and surface finishes at the end of their life all let moisture into the structure. On a flat roof over a habitable room, that shows up inside fairly quickly.

We carry out flat roof waterproofing across the north Costa Blanca, including tracing existing leaks, repairing damaged areas and refurbishing surfaces that have deteriorated but are still sound underneath.

Condensation

Condensation and Black Mould

Not every damp-looking wall has rising damp. A good many have condensation.

Condensation happens when moisture in the air meets a surface cold enough for it to condense out. Poor ventilation, bathrooms and kitchens, drying clothes indoors and rooms that stay shut for long periods all push it along.

It is particularly relevant to holiday homes, which is a large part of the housing stock here. A property closed up for weeks or months with no air moving through it will produce condensation whatever the weather is doing outside.

Black mould around windows, in ceiling corners, on external corners of rooms or behind furniture pushed against an outside wall usually points at condensation and ventilation rather than water rising through a wall.

Getting this right matters, because treating condensation as rising damp is money spent on a problem the property does not have — and the mould comes straight back.

External walls

External Wall Waterproofing and Protective Coatings

The outside walls of a Costa Blanca property take a lot: months of strong sun, then periods of wind-driven rain. Render cracks, and once it cracks it lets water into the structure behind it.

We repair damaged exterior surfaces and apply protective coatings and rendering systems as part of a complete damp-proofing solution, rather than as a cosmetic job on its own.

It is usually the point at which the property gets a noticeable improvement in appearance as well, because the defects being repaired are the same ones making it look tired.

Surveys

Find the Cause Before Treating the Damp

The single most useful thing on this page.

This is the part we would ask you to take seriously, because it is what separates a damp treatment that works from one that does not.

Rather than arriving with one particular system to sell, we look at the property and work out where the moisture is most likely coming from. We take account of where the damp is, how the wall is constructed, the ground level outside, the terraces and roof above it, the plumbing, the condition of the exterior render and how the property is ventilated.

From there we can recommend a course of action — which occasionally is that the problem is not what it looked like at all.

Diagnosis → Treatment → Repair → Finishing. Because Dragon Reforms carries out complete property renovations, the building work needed after the damp has been dealt with is part of the same job.

Warning signs

Signs You May Have a Damp Problem

If these keep coming back after redecorating, something underneath is still wet.

• Black mould
• Musty or damp smells
• Paint bubbling or peeling
• Crumbling plaster
• Damp patches on walls
• White salt deposits
• Moisture around skirting boards
• Damp appearing after rainfall
• Mould behind furniture
• Cold or wet-feeling walls
• Staining on ceilings
• Damp in underbuilds or garages

Any one of them on its own may be nothing much. Several of them together, in the same place, usually means the wall is telling you something.

The work

Damp Proofing and Renovation Work

Investigation, treatment and the building work that puts the room back.

Images are for illustration purposes only.

Areas

Damp Proofing Across the North Costa Blanca

Nine towns with their own pages, because the property in each one is different.

Rather than a single page with a list of town names stuffed into it, each of these covers the property that town actually has — hillside underbuilds, old town houses, seafront apartments or fincas on the terraces.

Why choose us

Why Dragon Reforms

Dragon Reforms has been renovating property on the Costa Blanca since 1999, and damp proofing sits inside that rather than alongside it.

It means we can look past the visible damp patch at the building problem behind it, and then carry out the work that follows — waterproofing, rendering, plastering, tiling, decorating and refurbishment — without handing you between trades who each blame the one before.

Our office is in Callosa d'en Sarrià, so the towns on this page are genuinely local to us rather than a list copied off a map.

• Local Costa Blanca experience since 1999
• Finca, villa and town house specialists
• Damp investigation and diagnosis first
• Waterproofing and tanking
• Terrace, patio and flat roof solutions
• Rendering and remedial building work
• Complete renovation service
• Guaranteed work

Questions

Damp Proofing Costa Blanca — Frequently Asked Questions

Get in touch

Solve the Cause, Not Just the Damp Patch

If you have damp, mould, peeling paint, water penetration or a musty smell that will not go away, we will come and look at it, tell you what we think is causing it and recommend something proportionate.

Villa, finca, town house, apartment or underbuild — across Benidorm, Altea, Calpe, La Nucía, Finestrat, Villajoyosa, Alfaz del Pi, Albir, Polop and Callosa d'en Sarrià.