AC Expertises

Field of expertise

Water infiltration assessment

Locating where water actually gets in and establishing responsibility before the damage spreads.

The problem

Water ingress rarely shows itself where it starts. Water travels along a roof structure, a slab or insulation and appears several metres away, which often leads to repairs being carried out in the wrong place.

The Luxembourg climate, with frequent rain and windy spells, puts roofs, accessible terraces, balconies and façades under real strain. Detail points — flashings, upstands, outlets, thresholds of glazed openings — account for most of the damage.

In recent buildings the cause is often a single execution defect: an upstand that is too short, a membrane punctured while fixing a balustrade, or a poorly formed junction between two materials.

In existing buildings, ageing joints, cracked render and blocked outlets explain the majority of the cases we come across.

Warning signs

  • Stains on ceilings or high on walls: brownish marks that reappear after every spell of rain indicate active ingress.
  • Blistering render or paint: a finish lifting in patches reflects persistent moisture in the substrate.
  • Marks under a terrace or balcony: the underside of external slabs often reveals failing waterproofing before any other sign.
  • Damp smell in a closed room: cellars, garages and utility rooms can take in water with no immediately visible damage.
  • Damage linked to wind direction: problems that only occur with driving rain from one side point to a specific façade or window.

Our assessment method

01

Inspection of entry points

We examine the roof, façades, joinery, terraces and below-ground areas to identify weaknesses through which water can pass.

02

Measurements and testing

Moisture readings, examination of detail points and, where needed, targeted water testing confirm the real path of the water rather than assuming it.

03

Establishing the cause

We distinguish design faults, workmanship faults, normal ageing and lack of maintenance — a distinction that shapes everything that follows.

04

Report and recommendations

The report locates the source of the problem, describes the repairs required and sets out the checks to carry out once the works are complete.

In which setting

An amicable assessment often unlocks a situation: it gives owners, contractors, managing agents and insurers a shared technical reading of the damage and avoids unnecessary works.

Where disagreement persists, particularly over which warranty applies or how responsibility is shared, the report of a sworn judicial expert provides solid support in proceedings or negotiation.

Unsure about your building?

Tell us about your situation: we will set out the most appropriate scope of work and arrange the visit as promptly as possible.

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