In a newly built residential development, water ingress in the garages, damp in the floor slabs and stains in the storage rooms are appearing after spells of rain. Faced with this problem, the key question arises: what is the real cause of the water ingress in the garage?
Although the developer sometimes blames the homeowners’ association’s maintenance, most often water ingress in garages is due to faults in the waterproofing or in the drainage system of the areas in contact with the ground or the outside.
Main causes of water ingress in garages
- Defective waterproofing in roofs, ramps or landscaped areas above the basement
When the garage lies beneath courtyards, paved areas or landscaped areas, water ingress can be caused by:
-A waterproofing membrane that is poorly installed, deteriorated or punctured
-Poorly sealed junctions (drains, columns, structural joints)
-Lack of protection for the waterproofing before the ground is backfilled
Rainwater then passes through the building system and ends up “weeping” through the floor slab, causing water ingress in the garage.
2. There may be problems with the building’s perimeter drainage
-Poor drainage encourages water to build up against the structure, causing persistent damp.
-Drains that are missing, blocked or poorly connected
-Ground slopes that are incorrect or fall towards the building
-Drainage wells without sufficient capacity
- Defects in walls in contact with the ground (storage rooms in the garage)
-Water ingress can also originate in poorly built vertical elements:
-No drainage membrane or vertical waterproofing
-Render not suitable for hydrostatic pressure
-Lack of adequate ventilation in storage rooms
These faults cause damp stains, efflorescence and a persistent musty smell.
Can poor maintenance cause water ingress in garages?
In the case analysed, the garage lies beneath a paved communal area with a children’s play area. The developer attributes the water ingress to drains blocked through lack of maintenance.
However, in a new build, a properly designed and built system must withstand normal rainfall without causing structural water ingress in the garage, even when there are occasional maintenance issues. A problem originating in poor workmanship and/or deficient design cannot be blamed on poor maintenance. The parties involved in the construction must answer for their liability.
An adequate building system must include:
-Continuous waterproofing beneath the outdoor paving
-A protection and drainage layer
-Falls correctly formed towards the drains
-Drains with sufficient capacity and an overflow
-Junctions correctly sealed at kerbs, play equipment and joints
When water only builds up because of an occasional blockage, what normally appears is puddles on the surface, not water ingress through the floor slab. For this reason, water ingress in garages usually points to a design or workmanship defect, not simply a lack of maintenance.
Solution for water ingress in the garage
The right way to solve water ingress in the garage is to tackle the source of the damage, not just the symptoms. Repairs “from the inside” (painting, resins on the garage ceiling, covering up the damp) should be avoided. The solution must be applied from above and act directly on the source of the problem, exposing the waterproofing and redoing it in the correct manner, and then reinstating all the elements.
To do this, the right first step would be to commission an expert report from an expert specialising in building defects to determine the causes of the water ingress in the garage and, once the source of the problem has been located, to propose the most suitable solution. On the basis of that report, a claim should be made against the developer so that it carries out the repairs exactly as the expert specifies, or pays compensation in lieu so that the homeowners’ association can carry out the repairs itself.
If your new-build residential development has a problem with water ingress in the garage and the developer is not repairing it properly, contact us.
Any questions?