What to check after the rainy season: damp, façades, terraces and external walls

Quick answer: what should you inspect after a period of rain?

After a rainy season, it is advisable to inspect the following areas in particular:

Water ingress, loose elements and damage that may affect safety should be dealt with before purely cosmetic defects.

Wait until it is safe before carrying out an inspection

Do not access a wet roof, terrace or roof covering if there is a risk of slipping or falling.

The initial inspection can be carried out from inside the property and from accessible outdoor areas. Work at height, on sloping roofs, cornices or façades should be left to professionals with the appropriate protective equipment.

After heavy rainfall:

1. Photograph any marks or damage.
2. Make a note of when they appeared.
3. Check whether they become worse after further rainfall.
4. Remove objects that are in contact with wet areas.
5. Ventilate the rooms when conditions allow.
6. Do not cover the mark with paint until its cause is known.

Documenting the damage helps distinguish recent damp from an old mark and makes subsequent diagnosis easier.

In what order should the property be inspected?

The inspection is more useful when it follows the route that the water may have taken.

The recommended order is:

1. Interior ceilings and walls.
2. Terraces, roofs and balconies located above them.
3. Façades and external junctions.
4. Windows, doors and seals.
5. Metal gates, railings and enclosures.
6. Basements, garages and walls in contact with the ground.
7. Drains, gutters and water discharge areas.

An interior stain is not always directly below the point where the water entered. Water can travel through joints, floor slabs or cavities before becoming visible.

1. Inspect interior ceilings and walls

Walls and ceilings often show the first signs of water ingress.

Look for changes in colour, blistering paint, softened plaster, flaking, a damp smell or marks that appear after rainfall.

Common signs of water ingress

Damp related to rainfall often has one or more of the following characteristics:

• It appears or becomes worse after rainfall.
• It has an irregular shape.
• It is located near ceilings, façades or windows.
• It produces yellowish or brown marks.
• It causes the paint to lift.
• It produces whitish salt deposits.
• It returns even after the wall has been repainted.
• It is located below a terrace or roof.

Not all damp marks have the same cause. Condensation usually appears in cold corners, around windows and in poorly ventilated rooms, while rising damp normally travels upwards from the lower part of a wall.

Our guide on how to distinguish condensation, water ingress and rising damp explains the most common signs of each problem.

Do not repaint the wall immediately

Painting a wall that still contains moisture can cause new blisters, stains and flaking.

The correct order is:

1. Locate the point where the water is entering.
2. Repair the cause.
3. Remove deteriorated materials.
4. Allow the substrate to dry.
5. Treat mould or salt deposits where necessary.
6. Apply a compatible primer.
7. Repaint using the appropriate system.

If the marks return, affect several rooms or the source of the water is unclear, it is advisable to request a professional damp diagnosis and removal service.

2. Inspect terraces, flat roofs and balconies

Terraces are among the first areas that should be inspected after prolonged or heavy rainfall.

Even when the paving appears to be in good condition, water may enter through joints, corners, skirting areas, drain outlets or small movements in the substrate.

What to inspect on a terrace after rainfall

Check:

• Whether puddles remain for many hours.
• Whether the drain outlets remove water correctly.
• Whether any joints have opened.
• Whether there are cracks in the paving.
• Whether any tiles move or sound hollow.
• Whether the junctions between the floor and walls have deteriorated.
• Whether skirting tiles have separated.
• Whether there are cracks around pipes.
• Whether visible waterproofing has developed blisters or bubbles.
• Whether marks have appeared on the ceiling of the floor below.

The most vulnerable points are usually corners, drain outlets, changes in level and junctions with walls.

Puddles are an important warning sign

Standing water does not by itself prove that there is a leak, but it indicates that drainage or the falls may be inadequate.

Standing water keeps joints and coatings wet for longer and can accelerate their deterioration.

It is also advisable to check whether leaves, soil or dirt are blocking the drains. Cleaning should only be carried out when the area is accessible and safe.

Do not waterproof without locating the point of entry

Applying waterproof paint across the entire terrace may not solve the problem if the water is entering through a drain outlet, a crack in the parapet or a junction with the façade.

The solution will depend on:

• The condition of the paving.
• The type of substrate.
• The falls.
• The extent of the damage.
• The previous waterproofing system.
• How the terrace is used.
• Whether water ingress is affecting the property below.

You can find more information in our guide to waterproofing a terrace and avoiding common problems.

When there are active leaks, severely deteriorated joints, lifted paving or recurring water ingress, it is advisable to consider a professional terrace repair and waterproofing service.

3. Inspect façades and external walls

The façade is directly exposed to water, wind and changes in temperature.

After a rainy season, it may show damage that previously went unnoticed, such as more visible cracks, lifting paint, dark stains, powdery areas or coatings beginning to separate.

Signs to look out for

Check for:

• New cracks.
• Cracks that have become larger.
• Blistering paint.
• Flaking or peeling.
• Marks beneath terraces or balconies.
• Damp around windows.
• Green growth or mould in shaded areas.
• Salt deposits.
• Persistent streaks.
• Areas that sound hollow when tapped gently.
• Loose mortar or coating.
• Aged or deteriorated seals.

A superficial stain may only require cleaning. A crack, hollow area or loose coating requires a different assessment.

Our guide to the signs that a façade may need professional renovation helps distinguish paint wear from more serious deterioration.

Pay particular attention to junctions

Water often finds entry points around:

• Window surrounds.
• Window sills.
• Balconies.
• Cornices.
• Terrace parapets.
• Downpipes.
• Junctions between different materials.
• Service penetrations.
• Cracks near doors.
• Skirting and lower wall areas.

These points may require sealing, repair of the existing coating or a specific protective system.

A façade should not be treated as a purely decorative element

The Basic Health and Hygiene Document of the Spanish Building Technical Code includes protection against damp among the basic requirements applicable to buildings.

Therefore, if the façade has water ingress, loose materials or persistent damp, changing the colour is not enough. The substrate and the points through which water can enter must be repaired first.

Our façade repair, renovation and painting service allows the condition of the existing coating to be assessed and a solution to be applied that is suitable for façades exposed to a coastal climate.

4. Inspect windows, doors and seals

External windows and doors are common points of water entry.

Water ingress may be caused by an aged seal, an open joint, a poorly installed sill or a blocked drainage outlet.

What to check

After rainfall, inspect:

• Damp marks around the frame.
• Water on the inside window sill.
• Lifting paint beside windows.
• Cracked sealants.
• Deformed rubber seals.
• Blocked drainage holes.
• Open joints between the frame and wall.
• Swollen wood.
• Rust on fittings.
• Doors that rub or no longer close properly.

Not every problem can be solved by adding more silicone. Before resealing, check whether the existing product is still firmly adhered, whether the joint needs to accommodate movement and whether the water has a suitable drainage route.

Blocking the drainage holes in a window or door frame can make water accumulation worse.

5. Inspect metal gates, railings and enclosures

Rain and humidity can accelerate corrosion when the protective paint has small cuts, knocks or poorly adhered areas.

After a wet season, rust often appears first on welds, screws, corners, supports and lower sections.

Early signs of corrosion

Look for:

• Small orange marks.
• Blistering paint.
• Small areas of flaking.
• Rough surfaces.
• Rust around screws.
• Loss of paint around welds.
• Rust stains on the wall.
• Joints that are beginning to weaken.
• Water trapped inside hollow sections.

When the rust is superficial, treatment may involve removing the corrosion, sanding, cleaning, applying an anticorrosive primer and renewing the finish.

Painting directly over loose rust does not stop the process. Corrosion will continue beneath the new coating.

You can consult our metal enclosure treatment service in Jávea for gates, fences, entrance gates, doors and railings.

You can also find maintenance recommendations in our article about iron gates and railings.

Pay attention to safety-related elements

A railing, metal staircase or enclosure affected by deep corrosion should be inspected as a priority.

When rust has reduced the thickness of the metal, affected welds or weakened fixings, the problem is no longer purely cosmetic.

6. Inspect exterior wood

Prolonged rainfall can affect wooden doors, windows, shutters, beams, pergolas and other timber elements.

Loss of varnish or wood stain allows water to penetrate more easily.

Signs of deterioration

Check whether the wood shows:

• Swelling.
• Cracks.
• Dark marks.
• A greyish colour.
• Cloudy or whitish varnish.
• A lifting or peeling finish.
• Soft areas.
• Rusty fittings.
• Doors or windows that no longer close properly.
• Small holes or traces of powder.

Wet wood should not be varnished immediately. It must first be checked for deterioration, allowed to dry and properly prepared.

When old coatings are lifting, deep stains are present or the wood has lost strength, a professional interior and exterior wood treatment may be required.

7. Inspect basements, garages and ground floors

Lower levels can develop problems that differ from those found on terraces or façades.

After heavy rainfall, inspect:

• Walls in contact with the ground.
• Junctions between floors and walls.
• Poorly ventilated storage rooms.
• Garages.
• Plant and utility rooms.
• Skirting areas.
• Walls close to gardens.
• Internal drain outlets.
• Sump pumps, where fitted.

A mark rising from floor level may be related to rising damp, but it may also be caused by lateral water ingress or a temporary accumulation of water in the surrounding ground.

The shape of the mark and the way it changes after rainfall can help guide the diagnosis, but they do not replace an inspection when the problem is recurring.

8. Inspect drains, gutters and downpipes

A blockage can cause water to overflow and enter areas that would normally remain dry.

Visually inspect:

• Gutters filled with leaves.
• Displaced downpipes.
• Open joints.
• Slow-running drains.
• Blocked grilles.
• Water being discharged directly against a façade.
• Water outlets located close to doors.
• Vertical marks below a downpipe.
• Damp around brackets or joints.

Do not dismantle downpipes or access roofs without the appropriate equipment.

When a downpipe passes through a façade or is concealed, a leak can produce marks some distance away from the visible point of failure.

How to tell whether rain caused the problem

A connection between rainfall and damp is more likely when:

• The mark appears after a period of rainfall.
• It becomes worse after each new rainfall event.
• It is close to a façade, roof or terrace.
• The surface improves during dry periods.
• There is a deteriorated crack or joint outside.
• It appears beneath a drain outlet or downpipe.
• There is flaking on the external face.
• The damp is concentrated on an elevation exposed to wind-driven rain.

However, rainy periods may also coincide with higher ambient humidity and reduced ventilation. A condensation mark should therefore not automatically be mistaken for water ingress.

Which problems should be repaired first?

Immediate priority

Action should be taken as soon as possible when there are:

• Active leaks.
• Water near electrical installations.
• Coatings or components that may become detached.
• Weakened railings.
• Bulging ceilings.
• Continuous water ingress.
• Loose tiles or elements.
• Wood that has lost its strength.

High priority

The following should not be postponed for long:

• Cracks that are becoming larger.
• Recurring damp.
• Open joints.
• Exterior paint that is flaking.
• Widespread rust.
• Mould that keeps returning.
• Persistent puddles on terraces.
• Completely deteriorated seals.

Planned maintenance

The following can be scheduled when conditions are suitable:

• Uniform loss of colour.
• Small areas of flaking without active damp.
• Localised surface rust.
• Worn varnish.
• Superficial green growth.
• Decorative interior renovation.

How long should you wait before repairing or painting?

There is no single waiting period.

Drying time depends on the material, the amount of water absorbed, ventilation, temperature and the source of the water ingress.

A surface may feel dry while still retaining moisture in the underlying layers. Before applying primers, paints or waterproofing products, it is therefore advisable to check that the substrate meets the conditions specified by the manufacturer.

The correct process is:

1. Stop the water from entering.
2. Remove loose materials.
3. Improve ventilation.
4. Allow the substrate to dry.
5. Check that the mark is no longer increasing.
6. Treat salts, mould or rust.
7. Repair cracks and defects.
8. Apply the finishing system.

Common mistakes after a rainy season

Painting over the mark

This may temporarily improve its appearance, but the damp will mark the wall again if the source of the water ingress is not repaired.

Sealing without removing deteriorated material

New sealants can detach if they are applied over aged silicone, dirt or wet surfaces.

Waterproofing only the visible area

The point where the mark appears does not always coincide with the place where the water is entering.

Cleaning a façade with excessive pressure

Incorrect pressure can remove paint, damage joints or force more water into cracks.

Painting directly over rust

The rust must be removed and the metal properly prepared before the primer and finishing coat are applied.

Varnishing damp wood

Trapped moisture can cause poor adhesion, staining and premature deterioration.

Ignoring a problem because it disappears during summer

Water ingress may dry out during the warmer months and return during the next rainy season.

Checklist after rainfall

Interior

• Inspect ceilings.

• Look for new marks.

• Check for blistering paint.

• Inspect corners and windows.

• Make a note of damp smells.

• Photograph the damage.

• Check whether it becomes worse after further rainfall.

Accessible terraces and roofs

• Inspect joints.

• Clean accessible drain outlets.

• Check whether puddles remain.

• Look for cracks.

• Inspect skirting areas and junctions.

• Check for loose tiles.

• Inspect the ceilings below.

Façades

• Look for new cracks.

• Inspect lifting paint.

• Check for hollow areas.

• Look for green growth or salt deposits.

• Inspect windows and balconies.

• Check downpipes.

• Inspect skirting areas and cornices.

Doors, windows and enclosures

• Inspect window seals.

• Look for rust on metal gates and railings.

• Check welds and screws.

• Inspect metal doors.

• Check for swollen wood.

• Inspect fittings.

• Check that doors and windows close properly.

When to request a professional inspection

It is advisable to call a professional when:

• The point where the water is entering cannot be found.
• The damp returns after every rainfall.
• Access to roofs or elevated areas is required.
• Loose or falling materials are present.
• The terrace has recurring leaks.
• The façade has cracks or hollow areas.
• A railing is severely rusted.
• The wood has soft areas.
• The damage affects several parts of the property.
• Waterproofing, repairs and painting need to be coordinated.

A professional inspection helps establish which repair should be completed first and prevents the use of incompatible products or purely temporary solutions.

Frequently asked questions

What should I check first after heavy rainfall?

The first areas to inspect are ceilings, walls, windows and spaces located beneath terraces or roofs. Active leaks, loose elements or water close to electrical installations should be treated as priorities.

How can I tell whether a damp patch was caused by rain?

Water ingress usually appears or becomes worse after rainfall and may be found near a façade, window, terrace or roof. However, it must be distinguished from condensation and rising damp.

Can I paint a wall once the damp patch appears to be dry?

The wall should not be painted until the source of the water ingress has been repaired and the substrate has been confirmed as dry. Otherwise, stains, blistering and flaking paint may return.

What should I inspect on a terrace after rainfall?

Check the drain outlets, joints, corners, skirting areas, cracks, falls, loose tiles and any signs of damp or staining on the floor below.

Do puddles mean that a terrace is leaking?

Not necessarily, but they indicate that water is not draining correctly. Prolonged standing water can accelerate the deterioration of joints and waterproofing systems.

When does a façade need repairing after rainfall?

A façade needs inspection when it has cracks, lifting paint, water ingress, salt deposits, hollow areas, loose materials or damp around windows and balconies.

What should I do if rust appears on a metal gate after rainfall?

The rust and poorly adhered paint should be removed, the surface properly prepared and an anticorrosive primer applied before the finishing coat. Painting directly over rust usually produces a short-lived result.

Can rain damage wooden doors and windows?

Yes. If the protective finish is worn, the wood may absorb water, swell, become stained or develop cracks. It should be allowed to dry and properly prepared before a new treatment is applied.

When should I call a professional?

Professional assistance is advisable when there are active leaks, recurring water ingress, significant cracks, loose materials, damage at height, extensive corrosion or uncertainty about the source of the damp.

Conclusion: after rainfall, diagnose first and repair afterwards

An inspection after the rainy season can reveal small areas of water ingress before they affect coatings, paint, wood or metal elements.

The key is not simply to conceal the visible mark. The point where the water is entering must first be identified, the cause repaired, the substrate allowed to dry and the appropriate treatment or finishing system applied afterwards.

At Bartolomé Bas Painters, we have been inspecting, repairing and protecting homes in Jávea, Dénia, Moraira and the northern Costa Blanca since 1984. Our services include damp treatment, terrace waterproofing, façade work, house painting and the maintenance of metal enclosures and wood.

Contact Bartolomé Bas Painters to request an assessment and determine which repairs your property needs after the rain.