Repairing Waterlogged

STRUCTURE In Foundation Walls

Water-excluding Structures

Homeowners sometimes are baffled whenever a water-excluding structure such as a basement or cellar in the house experiences penetration and infiltration of groundwater and damp patches on walls or ceiling. When this happens, it is essential, you have your eye on it or have a seasoned waterproofing specialist inspect the basement for possible corrosion of reinforcement, that might result in cracking and spalling of concrete cover.

Leaking In The Basement

Leaking in the basement can be cumbersome especially when it is impossible to have access to the outside of the walls which however makes it difficult to guarantee to seal the leaks. A totally dry environment is critical for humidity control to achieve the best performance level of protection to suit the basement use. The following factors are important to be routinely checked

✓  Basement used for plant rooms, workshops e.t.c – may experience some seepages and damp patches. Groundwater should be checked for chemicals that may have a deleterious effect on the structure or internal finishes.         

✓  Basement used for office space, leisures  require a dry environment with reinforced concrete   

It is sensible to first diagnose the causes of faults and deterioration in liquid retaining structures before embarking on reparation. Understanding the extent of these faults and the likely cost of remedial work can help shape the efficiency of work done by professionals that might take on such tasks.

Remedial Fix to Joints

Major water loss is more likely to occur through joints and cracks than through areas of honeycombed concrete. For instance, remedial work to joints requires sealing grooved sealed with a flexible durable sealant and with a water bar. In our work experience, we have found cases apparently where the sealant has been omitted. It is advisable to use a crack injection if a sealing groove has not been provided. Sealants can be used with a primer in the application of damp concrete.

Remedial Fix to Foundation Cracks

Cracks and joints are two different phenomena in the foundation repair sphere. While joints can be extended through the walls, roof, or floor of a building a crack is a breaking line on the surface leaving a crevice or fissure that may lead to substantial damage if not detected on time. So the need to repair them will normally depend on:

✓  Whether the cracks are associated with corrosion of reinforcement revealed by spalling

✓  Whether the gap in the structure further deteriorates through the structure.

✓  Type of cracks and whether further movement across the crack is anticipated, and that includes the magnitude of the movement.

Homeowners can apply the following methods to remedy cracks not usually associated with deteriorating movement

✓  Removing laitance from the concrete for a distance of 75 mm. You can successfully do this by using power-operated wire brushes, light grit blasting, or high-velocity water jets. You would carefully remove all underlying grit and dust from the surface.

✓  Prepare and brush the line of the cracks with suitably formulated low viscosity and slightly flexible epoxy resin followed by the application of primer.

✓  A bonding coat or the application of an epoxy resin barrier

Remedial Fix to Concrete Wall Slabs

Property owners are seldom aware that a wall can not be completely watertight unless it is covered with a durable water-resistant membrane. So if your building experiences leaking, then this is an indication of a defective membrane. The practical solution is to provide a new membrane in the form of a puncture-resistant sheet material that possesses high strength to resist normal building movement.

Cracking and spalling of the concrete resulting from the leakage should be repaired in accordance with good practices by a qualified professional. Chances are you need to consider the installation of a system of cathodic protection or method of chloride removal. This method provides permanent protection against the corrosion of reinforcement by chloride ions in the concrete.

Wall Dampness

Slow penetration of water into patches on walls and ceilings results in dampness, sometimes making a correct diagnosis challenging and requires considerably experienced personnel to get it right. The state of condition where moisture is being drawn upwards from damp sub-soil and penetrating slowly through the concrete can be a daunting one where the basement is shallow. If the floor or walls have an impervious covering then there is a likelihood that wet patches will form behind the impenetrable covering. 

The reason why it is essential for floors to be provided with a waterproof membrane when the property was first built. But, note, rising dampness in concrete walls may be uncommon however, if the walls are in contact with a damp sub-soil, then the moisture may slowly penetrate through and may rise upwards to cause damage.

So check for leaking water pipes, or waste pipes from a sink or bathroom fitting for the source of wall dampness. It is important to check for damp areas on walls to correct and eliminate the early likelihood of mold growth.

Remedial Measure to Ground Water Level

The installation of a subsoil drainage system around the building will help reduce moisture deposition into the sub-soil below the foundations. However, the possible effect of such a drainage system on the foundation of the building must be carefully considered. It is noteworthy to remember that all clays shrink when they dry out due to high shrinkage characteristics may lead to defective joints and moisture rising from the ground causing damage to the membrane of waterproof if installed.