Stadium stands waterproofing protects more than the seats on top. Underneath most concrete stands sit changing rooms, offices, shops, corridors and plant rooms. When rain or cleaning water gets through the steps, it drips onto these spaces and attacks the steel inside the concrete. In Egypt, stadiums and sports clubs also face strong sun, dust and heavy crowds on match days. This guide explains a liquid polyurethane system for concrete stands, built from three Krypton Chemical products.
Contents
- Why Concrete Stands Leak
- The Liquid System for Stadium Stands Waterproofing
- Preparing the Concrete Steps
- Applying the Stadium Stands Waterproofing System
- Return to Service and Upkeep
- Common Mistakes in Stadium Stands Waterproofing
- FAQ
- Conclusion
Why Concrete Stands Leak
In simple terms, a stand is a long staircase of treads and risers. Every step has an inside corner where water sits, and an outside edge that takes impacts. As a result, several weak points repeat hundreds of times:
- the joints between precast stand units;
- cracks at the corner between tread and riser;
- holes drilled for seat fixings and handrail posts;
- poor falls that leave water standing on each tread;
- blocked or undersized drains at the ends of each row.
Water also gets in through the large movement joints that divide long stands. Those joints need their own detail, as we explain below.
The Liquid System for Stadium Stands Waterproofing
For stadium stands waterproofing, a liquid membrane works well because it follows every step, corner and fixing. Also, there are no laps to fail at each tread. The system here has three layers.
| Layer | Product (Krypton Chemical) | Role |
|---|---|---|
| Primer | Rayston Epoxy 100 | Seals the concrete and improves bonding |
| Membrane | Impermax LY | Elastic polyurethane waterproofing layer |
| Topcoat | Colodur (pigmented) | Wear, weather and colour protection |
Impermax LY is a one-component, cold-applied polyurethane membrane. Its sheet lists “stairs, stadiums, stands” among its uses, along with balconies, terraces and floors with light foot traffic. In addition, it gives a maximum elongation above 600% and a tensile strength above 2.5 MPa. On concrete with an epoxy primer, the sheet lists an adhesion of 1 MPa.
Colodur is an aliphatic polyurethane resin. Its sheet describes it as surface protection for aromatic polyurethane membranes, and it does not yellow in sunlight. The Impermax LY sheet also names Colodur as a decorative layer that can be renewed when worn.
Preparing the Concrete Steps
Good stadium stands waterproofing starts with sound concrete. Fortunately, all three sheets set the same base rules. The support must be compact, with a pull-off strength of at least 1.4 N/mm², tested to ASTM D4541 or a similar method. It must also be clean, dry and free of laitance, oil and loose particles.
In practice, the crew follows these steps:
- Grind or shot-blast the treads and risers to remove laitance.
- Repair broken nosings and spalled edges with a suitable repair mortar.
- Open and fill cracks before priming, as the sheets require.
- Check falls, so water drains off each tread.
- Clear and test the drains at the row ends.
- Confirm that support moisture is below 4%, the limit in the Colodur sheet.
Seat fixings and handrails
In stadium stands waterproofing, seat fixings deserve a decision before work starts. Ideally, the seats come off, the membrane goes on, and the seats return on sealed fixings. Drilling new holes through a finished membrane creates hundreds of leak points. So at Target we agree the seat layout and fixing method with the client first.
Movement joints
Similarly, the joints between stand sections move with temperature and loads. A membrane laid straight over them will tear. Therefore, each joint gets a dedicated joint detail before the membrane goes on. Our team handles this as part of repairing expansion joints.
Applying the Stadium Stands Waterproofing System
Step 1: Epoxy primer
Rayston Epoxy 100 is a two-component, high-solids epoxy. Its sheet gives a mixing ratio of 100 : 47 by weight and an adhesion of 5.0 MPa to concrete.
- Apply 200 to 500 g/m² by brush or roller.
- On very absorbent concrete, dilute the first coat with Rayston solvent, then apply an undiluted coat.
- On large areas, broadcast a little quartz sand into the wet primer for a rougher key.
- Apply within the pot life: about 40 minutes at 25 °C and 25 minutes at 35 °C.
- Do not apply on hot surfaces; the sheet sets 15 to 40 °C for the support.
Step 2: Impermax LY membrane
The sheet recommends two coats of 1 kg/m² each, in two different colours. That way, the crew can see any missed spots. Application is by roller, brush, spreader or airless spray. Straight after spreading, a spiked roller removes trapped air. Above all, the sheet sets an air temperature between 0 and 30 °C and a support temperature between 0 and 40 °C. In an Egyptian summer, that means early-morning work or cooler months.
Step 3: Colodur topcoat
Next, Colodur goes on at 200 to 500 g/m² by roller, brush or airless spray. A second coat follows once the first is no longer sticky, and within 24 hours. The pigmented version has a pot life of about 2 hours. The sheet sets a support temperature of 10 to 30 °C and air humidity below 85%.
For slip resistance on steps and aisles, the sheet tests Colodur with quartz sand of 0.4 to 0.9 mm spread on it. With sand, it reports slip resistance class 3 to UNE EN 12633. In white, it also lists a solar reflectance index of 104.5 to 105.4, calculated to ASTM E1980. So a light topcoat keeps the steps cooler for spectators.
Quality checks during stadium stands waterproofing
Stands are large and split into many rows, so thickness can drift from one row to the next. That is why we track quality with a few simple checks:
- calculate the quantity for each row from its area, then compare it with the material used;
- make sure the first membrane colour does not show through the second coat;
- record air and surface temperature and humidity at the start of each shift;
- run pull-off tests on sample steps after preparation and before priming;
- test the drainage of a full row with water before the topcoat, to find any ponding.
Return to Service and Upkeep
Timing matters, especially before match day. Impermax LY usually takes foot traffic after 1 to 2 days and reaches about 90% of its properties in 3 days. Its final hardness takes 10 to 15 days. Colodur takes light traffic after 24 to 48 hours at 25 °C, while the sheet suggests 7 to 10 days before normal traffic. As a result, a stand should stay closed to crowds for at least a week after the topcoat.
After that, regular care keeps the system working. For example, clear drains and gutters, remove debris after events, and wash with water and mild detergent. Strong acids are not suitable for cleaning. When the topcoat wears in busy aisles, a fresh coat of Colodur restores it.
Common Mistakes in Stadium Stands Waterproofing
- Coating over weak laitance without a pull-off check.
- Working in midday summer heat, beyond the sheets’ temperature limits.
- Running the membrane straight over movement joints.
- Drilling seat fixings through the finished membrane.
- Skipping the sand broadcast on steps, leaving them slippery when wet.
- Opening the stand to crowds before the topcoat cures.
FAQ
Can stadium stands waterproofing go over old tiles?
The Impermax LY sheet lists ceramic tiles among possible supports. However, every tile must be firmly bonded, and loose ones must be removed and patched first.
Why does stadium stands waterproofing need a topcoat?
The membrane gives the watertight layer. On top of it, the aliphatic topcoat adds wear resistance, colour stability and slip resistance with sand. Read more about our aliphatic topcoat.
Does the same stadium stands waterproofing suit indoor arenas?
Yes, but these products contain solvents and isocyanates. So indoor work needs strong ventilation and no ignition sources, as the sheets require.
Conclusion
Stadium stands waterproofing works when the details get as much attention as the large areas. Sound, primed concrete, a two-coat Impermax LY membrane and a sanded Colodur topcoat make a durable, walkable system. Planning seat fixings, joints and curing time before match day completes the job.
Target applies liquid applied membranes across Egypt. Contact Target to survey your stands before the next season.
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