The Complete La Marina Villa Owner FAQ & Guide Costa Blanca
Moisture, Cracks & Structural Movement.
Why this damage occurs — genuine structural causes
1. Moisture (Water Ingress)
Moisture in La Marina is caused by:
Missing or inadequate waterproofing in 1990s construction
Capillary water absorption through unimpregnated masonry
Hydrostatic pressure in terraces and pool areas
Insufficient drying times in new buildings (very common today)
Salt pollution of the Costa Blanca → salt attracts water
Missing vapor barriers in interiors
Cracks in the exterior plaster → water penetrates and remains in the masonry
Incorrect tile installation (no drainage system, no flexible adhesive and no or to smal joints)
2. Hairline Cracks
Cracks are caused by:
Temperature fluctuations (Costa Blanca: 5°C at night → 35°C during the day)
Concrete shrinkage
Subsoil settlement (La Marina has many filled plots)
Inadequate reinforcement in old buildings
Rigid tiles on a shifting substrate
Moisture in the masonry → volume changes → cracks
New buildings completed too quickly → concrete doesn't dry properly
3. Structural Movement
Movement is caused by:
Soil settlement (sand + clay = unstable)
Insufficient foundation depth in 1990s villas
Poor subsoil compaction
Weak ring beams → walls move against each other
Vibrations from pool pumps / road traffic
Moisture under terraces → screed lifts or sinks
How to solve these problems professionally
1. Diagnosing the Moisture Source
Moisture must first be clearly located before any repairs are worthwhile.
Check capillary moisture using CM measurement.
Inspect exterior plaster for microcracks.
Open a small section to measure masonry moisture.
Check terraces for hollow areas (tapping test).
Identify water pathways by efflorescence.
2. Properly Stop the Moisture
The cause is eliminated, not just cosmetically covered.
Remove exterior plaster and apply a flexible, two-component waterproofing membrane.
Re-seale terraces with a drainage system and flexible adhesive class C2TE S1.
Protect interior walls with waterproofing plaster and a vapor barrier.
For new buildings: Observe drying times (concrete: minimum 28 days).
3. Correctly Repair Cracks
Cracks must be treated according to their cause, not just filled.
Hairline cracks: Elastic crack sealant
Movement cracks: Crack injection with epoxy resin
Facade cracks: Reinforcing mesh + mineral plaster
Tile cracks: Replacement + flexible adhesive class S1/S2
4. Stabilize structural movement
Movement must be stopped before new damage occurs.
Check foundation, underpin if necessary
Reinforce or replace ring beam
Rebuild terraces with compacted subgrade
Install expansion joints (every 4–6 meters)
Decouple pool surround to reduce vibrations
5. Long-term prevention
After the repair, the building is optimized for the Costa Blanca climate.
Protect exterior facade with hydrophobic impregnation
Construct terraces with drainage + flexible waterproofing
Keep interiors stable with dehumidifiers
Regularly check pool and equipment
Annual visual inspection of the facade
Leaking Roofs and Terraces
How to Repair Roofs and Terraces Professionally (Real Solutions)
1. Complete Removal of the Old Bitumen Membrane
The old waterproofing must be completely removed because:
Bitumen cannot be reworked
The new waterproofing will not adhere otherwise
Voids will remain
Moisture will be trapped
This is the only correct way.
2. Check and Rebuild the Screed (If Necessary)
If the screed:
Sounds hollow
Is damp
Has cracks
Is coming loose
→ It must be partially or completely replaced.
3. Professional Waterproofing Systems (proven since 1997)
Here are the systems that work most reliably in La Marina:
A) 2-Component Liquid Waterproofing (Polyurethane / PU)
This is the best solution for:
Flat roofs
Terraces
Roof terraces
Balconies
Advantages:
100% waterproof
Elastic (ideal for heat)
UV-resistant
Crack-bridging
Seamless
Adheres to concrete, screed, and tiles
B) Cementitious Waterproofing (2-Component Flexible Sealant)
Ideal for:
Terraces under tiles
Pool surrounds
Damp screeds
Advantages:
Vapor-permeable
Flexible
Ideal for the Costa Blanca climate
Compatible with tile adhesive
C) EPDM Membrane (rare, but very effective)
For large Roofs:
Extremely durable
UV-resistant
Seamless
Ideal for new builds
4. Decoupling mats (e.g., Schlüter-DITRA)
These mats:
Prevent cracking
Decouple tiles from the substrate
Drain moisture
Significantly increase the lifespan of the terrace
In La Marina, they are mandatory when laying tiles on terraces.
5. New tiles with flexible adhesive (C2TES1/S2)
Why?
Flexible adhesives absorb movement
Prevent detachment
Reduce cracking
Are water-resistant
Outdated Electrical and Plumbing Installations
Why electrical installations from the 1990s are dangerous today
1. Undersized wiring (1.5 mm² instead of 2.5 mm²)
Many villas were fitted with 1.5 mm² wiring for electrical outlets.
That was common practice back then—today it's no longer permitted.
Why?
Modern appliances draw more power.
Air conditioners, heaters, and pool pumps put a strain on the wiring.
1.5 mm² overheats more quickly.
Insulation becomes brittle → risk of short circuits.
Fire risk increases significantly.
The following are now standard sizes:
2.5 mm² for sockets
4–6 mm² for air conditioners
6–10 mm² for instantaneous water heaters
separate circuits for pool equipment
2. Old fuse boxes without residual current device (RCD) protection
Many houses have:
old screw-in fuses
no residual current devices (RCDs)
no circuit breakers (MCBs)
no separate circuits
This means:
no protection against residual currents
no protection against defective appliances
no protection against moisture
high risk of electric shock
A 30 mA residual current device (RCD) is now mandatory — especially In
Bathrooms
Kitchens
Outdoor areas
Pool equipment rooms
3. Overloaded circuits
In the 1990s, electricity consumption was low:
No air conditioners
No pool pumps
No electric heaters
No induction cooktops
No photovoltaic systems
Today, circuits are overloaded because:
Too many devices are connected to one circuit
Wiring is too thin
Fuses are too weak or too old
There is no load balancing
Result:
Fuses constantly trip
Wiring gets hot
Outlets short-circuit
Fire hazard increases
Outdated Water Pipes (Plumbing)
Many villas still have:
galvanized or not galvanized steel pipes
copper pipes without protective coating
PVC pipes from the 1990s
outdated pressure reducers
Problems:
Rust → brown water and if steel pipes break you need a complete new instalation
Pitting corrosion → small leaks
Limescale deposits → pressure loss
old PVC pipes → brittle, burst in the heat
poor connections → dripping stains in walls
This is particularly common in La Marina because:
the water is hard (high in calcium)
the pipes were often laid close to the surface
the houses were built quickly
many installations were not carried out according to standards
When modernization is absolutely necessary
Electrical systems must be renewed if:
sockets get warm
fuses frequently trip
1.5 mm² wiring is used
no residual current device (RCD) is installed
air conditioners run through old pipes Running
Pool pumps are running on regular electrical outlets
The fuse box is older than 20 years
The water installation needs to be replaced if:
The water is brown or milky
The pressure fluctuates significantly
The pipes are noisy
There is visible dampness on the walls
Hot water is intermittent
Old steel or PVC pipes are present
Remember the water pipes install 2000 have only 15 years warranty, you can be happy if they still works. But needs to change.
How to solve these problems professionally (real technical solutions)
1. Complete electrical system upgrade
New wiring (2.5mm² / 4mm² / 6mm²)
New fuse boxes
30mA residual current device (RCD) for all circuits
Separate circuits for:
Air conditioners
Pool pumps
Kitchen
Bathroom
Outdoor areas
New sockets and switches
New grounding (many houses don't have it!)
2. Water system upgrade
Remove old steel pipes
New PEX pipes (best solution for Costa Blanca)
New pressure reducers
New shut-off valves
New hot water pipes
New connection technology (press fittings)
New outdoor lines for garden & pool
PEX is ideal because:
It doesn't rust
It doesn't calcify
It's flexible
It withstands heat and pressure
It's durable
Realistic costs (La Marina / San Fulgencio)
Complete electrical system renovation
Small villa: €2,500 – €4,500
Medium villa: €4,500 – €7,500
Large villa: €7,500 – €12,000
Water system renovation
Small villa: €1,800 – €3,500
Medium villa: €3,500 – €5,500
Large villa: €5,500 – €9,000
Fuse box replacement
€350 – €900
Retrofit residual current device (RCD)
€120 – €250 per circuit
PEX installation
€25 – €45 per meter
These figures are realistic for La Marina, based on typical projects since 1997.
La Marina renovation costs
Why Renovation Costs Vary So Much in La Marina (Real Technical Reasons)
Renovation costs depend not only on the materials used, but primarily on technical factors that are particularly relevant in La Marina:
1. 1990s Construction
Many houses were:
built quickly
with basic materials
without modern waterproofing
without insulation
with undersized electrical wiring
with PVC or steel pipes
As a result, renovations are often more extensive because existing damage must first be repaired.
2. Costa Blanca Climate
The climate causes:
high UV exposure → material wear and tear
high salt content → corrosion
extreme temperature fluctuations → cracks
high humidity → mold and moisture damage
Renovations therefore require the use of climate-resistant materials, which are more expensive but last longer.
3. Technical Installations
Many villas require:
new electrical wiring (2.5mm² / 4mm² / 6mm² cables)
new water pipes (PEX instead of PVC/steel)
new fuse boxes
new residual current circuit breakers (RCDs)
new pool equipment
These technical works have a greater impact on the price than the visible surface work.
4. Permits
ALL work requires a permit from the municipality of San Fulgencio: (Ayuntamiento)
structural alterations (Obra mayor)
extensions (Obra mayor)
terrace renovations (Obra menor)
pool renovations (Obra menor)
pool building (Obra Mayor)
new roofs (Obra menor if is a reparation)
all other smal renovation, wall build etc. goes with the (Obra menor)
major electrical modifications (Obra menor)
Permits cost time and money – and affect the overall price.
Cost ranges for common renovations in La Marina, San Fulgencio
We're talking about prices from registered companies with skilled workers with warranty, not handymen or wannabe builders.
Bathroom Renovation
Standard: €4,500 – €7,500
High-end: €8,000 – €14,000
Why?
Bathrooms require:
New plumbing
New waterproofing
New electrical wiring
High-quality tiles
Installations compliant with EU standards
Kitchen Renovation
Standard: €5,000 – €9,000
High-end: €10,000 – €18,000
Why?
Kitchens require:
New electrical circuits
New plumbing
High-quality countertops
Custom-made furniture
Appliance installation
Terrace Renovation
Standard: €3,500 – €7,500
High-end: €8,000 – €15,000
Why?
Terraces require:
Removal of old bitumen membranes
New waterproofing (two-component systems)
Uncoupling membranes
Flexible adhesives
Large-format tiles
Waterproofing (Roof & Terrace)
Standard: €1,800 – €4,500
High-end: €5,000 – €12,000
Why?
Waterproofing is technically demanding:
Old bitumen membranes must be removed
The screed needs to be repaired
Two-component waterproofing systems are expensive
UV-resistant materials are mandatory
Insulation
Interior: €2,000 – €6,000
Exterior: €6,000 – €14,000
Why?
Many houses lack insulation, therefore:
Walls need to be opened up
New pipes and wiring need to be considered
Insulation material must be climate-resistant
Complete Renovation (Full Villa)
Small Villa: €18,000 – €35,000
Medium Villa: €35,000 – €65,000
Large Villa: €65,000 – €120,000
Why?
A complete renovation includes:
Electrical work
Water pipes
Waterproofing
Insulation
Kitchen
Bathroom
Terraces
Pool equipment
Painting
Smart home integration
What truly affects the price
1. Material quality
High-quality materials:
last longer
are weather-resistant
reduce future repairs
Cheap materials lead to:
cracks
dampness
delamination
additional costs
2. Structural condition
If the villa:
has cracks
has dampness in the screed
has old pipes
has poor waterproofing
→ costs increase because damage must be repaired first.
3. Technical Installations
Electrical and plumbing systems are often the biggest cost factor:
New wiring
New fuse boxes
New PEX pipes
New pool equipment
New air conditioning units
4. Municipal Requirements
Permits affect:
Time
Costs
Material selection
Technical executio
With experience since 1997, we know exactly:
Where you can save money
Where you should never cut corners
Which materials work in the Costa Blanca climate
Which renovations will increase the villa's value in the long term
La Marina pool issues
1. Structural Cracks
Cracks are caused by several structural engineering factors:
A) Ground Movement (Settlement)
La Marina has many plots that were filled in during the 1990s.
The subsoil often consists of:
Sand
Clay
Uncompacted fill material
When the ground shifts, the pool shell moves → cracks develop.
B) Missing or Weak Reinforcement
Many pools were built with:
Insufficient steel
Incorrectly placed rebar
Inadequate ring beams
This results in stress cracks, especially:
at the corners
under the skimmer
at the steps
along the long walls
C) Temperature Fluctuations
Costa Blanca Climate:
5–10°C at night
35–40°C during the day
Concrete expands and contracts → microcracks → water loss.
2. Water Loss
Water loss is caused by:
A) Cracks in the concrete pool
As soon as water penetrates a crack, the following happens:
Water seeps into the ground
Chlorine attacks the concrete
The crack widens
Osmosis occurs (see below)
B) Leaky skimmers/inlet nozzles
The most common leak points:
Skimmer box
Inlet nozzles
Floor drain
Spotlight penetrations
Why?
Seals age or not good quality
PVC pipes come loose
Connections break due to ground movement
Chlorine attacks plastic
C) Pipes under the floor
Many pipes were:
without sand bedding
without protective sleeves
directly in the ground
with cheap PVC fittings and flexible pipe
Result: Hairline cracks in pipes → water loss.
3. Osmosis (Blistering / Osmotic Bubbles)
Osmosis is one of the most expensive types of pool damage.
It is caused by:
Water penetrating the concrete through cracks
Chemical reaction between water and polyester resin
Formation of acids
Pressure build-up under the coating
Blister formation (osmotic blisters)
Coating flaking
Osmosis cannot be repaired by simply painting over it.
It is a sign of deeper structural damage.
How to professionally repair pool damage (real technical solutions)
First, the leak must be found. We have our expert diver who searches the entire pool and finds every leak; this also includes pressure testing the pipes.
1. Repairing cracks (Crack Injection)
The correct method is:
A) Epoxy resin injection
The crack is opened
cleaned
injected with epoxy resin under pressure
The resin permanently bonds the concrete
The crack is structurally stabilized
B) Flexible sealant over the crack
After injection:
2-component flexible sealant
Fabric reinforcement
Protective layer
This ensures the crack remains sealed even with ground movement.
2. Repairing Water Loss
Depending on the cause:
A) Replace Skimmers/Nozzles
Remove old skimmers
Install new skimmers
New gaskets
New PVC fittings
New sealant
B) Renew Pipelines
Remove old PVC pipes
New pressure pipes (PN16)
New fittings
New shut-off valves
New pump connections
C) Seal the Bottom Drain
Remove the old gasket
New flange gasket
New bolts
New sealant
3. Professionally Repair Osmosis
Osmosis is the most complex repair.
A) Completely remove the coating
Grind off the polyester resin
Open the osmosis blisters
Remove the acid
Neutralize the concrete
B) Allow the concrete to dry
At least 2–4 weeks, depending on the moisture content.
C) Installing a New Waterproofing System
2-Component Epoxy Primer
2-Component Flexible Waterproofing System
Fabric Reinforcement
New Pool Paint or Tiles
Osmosis is a sign that the pool needs a complete overhaul.
When a Complete Pool Renovation Is Necessary
A complete renovation is advisable if:
Extensive osmosis is present
Cracks keep reappearing
Water loss cannot be located
The concrete pool shell is structurally weakened
The pipework is old or has been repaired multiple times
The waterproofing is older than 15–20 years
The pool looks outdated
A complete renovation includes:
New waterproofing
New tiles or pool paint
New skimmers
New jets
New lighting
New pipework
New pump technology
Aurea Luxe General Construction has been operating in La Marina and San Fulgencio under Swiss site management since 1997.
Reinhard Schäppi
All information in this FAQ is based on real renovations, repairs, and diagnostics carried out over nearly three decades.
The content shows villa owners which problems are typical, how a professional can correctly resolve them, and which steps are essential for reputable tradespeople.
This allows clients to better evaluate quotes, monitor tradespeople, and make informed decisions for their renovations.
