Crack filling to Stop seepage from External Walls, Bathroom, Kitchen, Terrace, Windows
Problem: Leakage from External Walls of the building
Observation: Rainwater ( Water leakage) entering inside house through walls.
Analysis: Rain water coming in through external walls due to cracks developed on walls. These cracks are developed due to expansion/ contraction of civil structure and micro movements.
Action Plan: Make v- groove and expand the cracks using grinder or manual tools. Clean the crackline/ groove, apply Supex PU 25 sealant to cover the cracks completely, excess sealant to be tooled away. After curing ( drying of sealant, 2-3 hrs) paint the crack filled area.
Supex PU 25 is a polyurethane sealant with exceptional elongation, gap filling and tensile strength properties. It is also used for crack filling of external/ internal cracks, seal expansion joints, bond building material.
Dampness of internal walls
Observation: Wetness or dampness on external side of bathroom walls.
Analysis: Water leakage from tiles joints of bathroom or leakage from plumbing joints of bathroom, Water seepage from soil below foundation, External cracks on walls.
Action Plan:
- Remove old joint filler from tiles of bathroom, seal with new tile joint sealant, Supex Bond all HT, replace old cracked tiles.
- Check the plumbing joints for leakage and seal seepage through joints.
- seal external cracks with Supex PU 25.
- In case of rising dampness due to capillary action of water coming from below foundation- injection grouting with epoxy or Polyurethane.
Stop Seepage from ceiling using crack filling sealants
Water leakage through cracks from terrace, parapet wall of terrace. seepage due to water leakage from bathroom/kitchen of the flat above.
Seal the cracks on terrace and parapet wall using Supex PU 25. Apply waterproofing membrane or coating for long life after crack sealing.
In case of leakage from Bathroom/kitchen from upper floors the source of leakage has to be plugged, there is nothing much you can do but request the flat resident to repair the leakage areas.
Water leaking through the windows during heavy rainfall
Gap between window frame and wall not sealed adequately. Aluminium frame fitted on granite or any stone not proper, leaving seepage path for rainwater.
Remove old sealant and apply Supex 500 / Supex 501 to seal gaps between window frame and wall.
Seal the edge of window frame and horizontal granite slab with Supex 501.
Stop water seepage through the metal roof sheet
Why Do Seepage and Leakage Occur?
To stop seepage effectively, we must first understand where it occurs and why it happens.
Where seepage is commonly seen
• House walls
• Walls next to bathrooms
• Ceilings
• Around windows during heavy rainfall
• Metal roof areas
How water enters these areas
• Rainwater enters through cracks in external walls
• Bathroom water seeps through tiles and appears on adjacent room walls due to capillary action
• Water penetrates through tile gaps and floor cracks in bathrooms
• Water passes through gaps between beams and external walls
• Rain enters through gaps between window frames and walls
• Water flows through gaps between metal sheets and concrete walls
Problems caused by seepage
• Damp and stained walls
• Dripping ceilings
• Flooded rooms during rain
• Rusting of TMT bars inside slabs
Over time, rusted steel expands. As a result, slabs weaken, crack, and swell. In severe cases, parts of the slab may collapse, creating serious safety risks.
Root causes of seepage in civil structures
Concrete forms the backbone of civil construction. However, concrete naturally expands and contracts with weather changes. Pollution, acid rain, poor workmanship, weak waterproofing, and faulty design make the problem worse.
Because concrete is rigid, beams, slabs, and columns develop cracks over time. These cracks allow water to pass through and damage embedded steel. Similarly, external walls crack and become easy water entry paths.
In addition, ineffective or missing sealants around windows, roofs, and joints allow rainwater to enter. Gaps between tiles further worsen water percolation.
Next, we will discuss how to proactively stop seepage at beam-wall and slab-wall joints.
Why leakage from walls and beam
This problem usually occurs during the monsoon seasons. During the rainfalls, water from the external walls seeps inside through the beam joints. This seepage causes moisture damage to the interior portions of the walls.
This entry of water occurs because there are minute gaps present between the beam and wall joints. The usual reasons for these gaps in new buildings are : inflexible material like thermocol or cement grouting is rigid and cracks with time. It can’t withstand expansion- contraction cycles , building movements. 
Such seepages lead to shabby homes with the paints peeling off, deterioration of walls, beams and columns. Thus, it significantly reduces the structural integrity of the building.
Traditional Method : Mortar used to fill gap between Wall & Beam joint.
Traditionally this joint is sealed using regular mortar and chips of bricks. However, this combination is rigid.They are exposed to weather fluctuations which cause expansion/ contraction and subtle building movements. Such joints crack and makes way for rainwater to seep into the walls.
PU Foam Spray to Stop Wall Seepage
Requirement
An isolation joint expanding PU foam spray sealant that delivers strong gap filling and long-term performance. It must fill gaps up to 1 inch or more. It should allow plastering, painting, and sanding like concrete. The material must be low cost, easy to apply, and durable. It should remain mildly flexible to accommodate building movement. Most importantly, it must be a proven technology in India and abroad.
Solution: Isolation Joint PU Foam Spray Sealant
Supex 100 is a one-component PU foam spray sealant, packed in a 750 ml can and applied using a gun. Once extruded into gaps or cracks, it expands rapidly to fill the joint completely. Initially, the foam is in liquid form. After expansion, it cures into a flexible material.
This flexibility is a major advantage. The foam compresses and decompresses with structural movement. As a result, it handles linear expansion better than rigid cement mortar. Therefore, the risk of beam-wall joint cracking reduces significantly.
In addition, the foam provides excellent thermal and acoustic insulation. It also offers electrical insulation, which enhances overall building safety.
Supex 100 PU Foam is available in both fire-retardant (FR) and non-FR variants. This allows easy selection based on project requirements.
Key Advantages
• 100% seepage-free beam-wall joints for the life of the building
• Faster application than cement mortar, reducing labour cost
• Adds thermal, acoustic, and electrical insulation
• Reliable, durable, and long-lasting performance
3 Responses
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