How much a metre for crack sealing a swimming pool Sealant must be able to be submerged in swimming pool The crack should about 7 to 10 mm and is 15 metres long Which sealant would you recommend?
However, your specific crack is quite wide (7 to 10 mm) and very long (15 metres). Because of these large dimensions, a standard DIY silicone tube will not suffice on its own. Standard pool silicones (like Sikasil Pool or Maxisil Pool) have a maximum joint depth limitation of 6–10 mm and cannot handle the immense water volume or volume shrinkage required for a 10 mm wide crack if applied directly without backing. [1, 2]
Material Requirement Calculations
To seal a crack that is 10 mm wide and 10 mm deep across 15 metres, you cannot simply fill the entire depth with sealant. [1]
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- The 2:1 Rule & Backer Rods: For a flexible seal to work underwater without tearing, the depth of the sealant should only be roughly half the width (or equal to it at maximum, up to 10 mm). You must use a closed-cell polyethylene foam backer rod pushed tightly into the crack first. This controls the depth and stops the sealant from sinking. [1, 2, 3, 4]
- Volume Required: A standard 300 ml cartridge yields approximately 3 metres of coverage for a 10 mm wide by 10 mm deep joint. For a 15-metre span, you will need at least 5 to 6 standard cartridges (300 ml each) to complete the job cleanly. [1]
Recommended Under-Water Sealants
The choice of sealant depends entirely on whether you intend to drain the pool to complete the work or attempt the repair fully submerged under water.
Option 1: Submerged / No-Drain Sealants (Hybrid Polymers)
If you do not want to drain 15 metres worth of pool water, you cannot use silicone. You must use modern MS-Polymers or specialized hybrid resins that are chemically engineered to cure fully submerged. [1, 2]
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- Underwater Magic TM (Highly Recommended): This is a high-performance single-component hybrid polymer specifically designed for open swimming pools. Unlike silicone, it is 100% silicone-free and can fill gaps up to 40 mm wide. It resists chlorine and salt water perfectly and can be applied directly underwater with a standard caulking gun. It costs roughly $134 AUD per tube. [1]
- Soudal Pool Fix: Another crystal-clear SMX polymer sealant meant for invisible underwater bonding and sealing around pool components. It is permanently elastic and contains strong fungicides to prevent underwater mould growth. It costs around $77 AUD. [1, 2]
Option 2: Dry Application Sealants (Premium Silicones)
If you choose to drain the pool and let the concrete surface dry completely, neutral-cure silicones offer excellent elasticity for shifting cracks but require a full week to cure before refilling. [1, 2]
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- Sikasil® Pool: A premium, neutral-curing silicone sealant built specifically for permanent water immersion in swimming pools. It features incredible chlorine resistance and high elasticity. It explicitly supports joint widths between 10 mm and 35 mm, matching your requirements. It costs approximately $26 AUD per tube at major retailers like Bunnings Warehouse. (Note: It is strictly unsuitable for saltwater pools).
- Maxisil Pool Silicone: A heavy-duty, commercial-grade neutral-cure silicone that stands up exceptionally well to pool chemicals and UV rays. It stays firmly in joints without slumping, making it ideal for a 10 mm wide vertical wall or floor crack. It costs around $32 AUD to $41 AUD. [1, 2, 3, 4]
To help narrow down the exact product and method, could you tell me:
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- Is your swimming pool chlorine or saltwater?
- Do you intend to drain the pool, or are you looking to apply this directly underwater?
- Is the pool shell made of concrete/render, fibreglass, or vinyl liner?
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Sika AustraliaSikasil® Pool | Sika Australia… and common swimming pool clean- ing chemicals. ▫. The resistance of sealant to chlorine is dependent on the water pH value and…
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Sika AustraliaSikasil® Pool | Swimming Pools – Sika AustraliaApplication * Backing material. Use closed cell, polyethylene foam backing rod. * Sag flow. < 2 mm (20 mm profile, +23 °C) (EN ISO…
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AquaBond AdhesivesSealants for Swimming Pools – AquaBond Adhesives16 Aug 2026 — Key Takeaways * Pool sealants must resist chlorine or salt, UV, and constant immersion—standard caulk fails fast. * Silicone, poly…
concrete, saltwater pool is empty crack will be submerge max 700 mm Crack will be opened where required, it's a temp repair to get it though the summer
For an empty, concrete, saltwater pool undergoing a temporary fix to last through the summer, your product options change significantly. Because the pool is a saltwater system, standard premium pool silicones like Sikasil Pool are completely ruled out because they are not rated for salt or magnesium systems. [1, 2]
Since you are opening up the crack, ensuring it is clean, and the repair will only be under a shallow 700 mm of water head pressure, you can use specialized, heavy-duty surface options.
Recommended Temporary Products for Saltwater Concrete
Because this is a temporary summer patch, you have two distinct approaches depending on how structural you want the quick fix to be:
Option 1: Maxisil Pool Silicone (The Flexible Elastomeric Seal)
Unlike other brands, Maxisil Pool is a 100% pure neutral-cure silicone specifically formulated to withstand harsh saltwater and magnesium chemical systems. [1]
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- Why it works for you: It will flex safely if the concrete continues to shift over the summer heat.
- Application strategy: Since you are opening the crack, make sure you grind it to a uniform depth. Insert a backer rod first so you only fill the top 8–10 mm with the silicone.
- Cure Time: It must cure completely in the dry pool for a minimum of 4 to 7 days before you refill the pool.
- Cost: Roughly $32 to $41 AUD per 310ml cartridge. You will need about 5 to 6 cartridges for a 15-metre run. [1]
Option 2: Epoxy Pool Putty or Hybrid Polymer (The Rigid Rigid Plug)
If you want something incredibly tough that acts more like a hard cementitious plug to completely stop the leak through the opened crack, a two-part pool epoxy or high-end hybrid polymer is perfect. [1]
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- Underwater Magic or Soudal Pool Fix: These MS-polymer/hybrid sealants are entirely saltwater resistant and can be applied to completely damp or dry concrete. They skin over rapidly and do not require a week-long dry cure like silicone. [1, 2]
- Epoxy Putty (e.g., Emerkit or Atlas Pool Putty): If you open the crack into a “V” shape, you can knead this 2-part epoxy and pack it tightly into the crack like clay. It cures rock-hard underwater or topside within hours and handles saltwater easily. [1]
- Cost: Soudal Pool Fix sits around $22 AUD a tube, while Underwater Magic costs roughly $80 AUD per full-size tube. [1]
Pro-Tips for a Successful Summer Patch
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- Undercut the Crack: When opening the crack, try to cut it into a square channel or an inverted “V” (wider at the bottom than the surface) if using putty. If you cut a standard “V”, flexible sealants can easily squeeze out under shifting pressure.
- Wash Out Carbonation: After grinding or chiseling the concrete crack open, pressure wash it thoroughly. Concrete dust prevents sealants from bonding to the substrate. Let it dry completely if using Maxisil. [1]
- Budget for Backer Rods: Do not skip the closed-cell foam backer rod. Trying to fill a deep 15-metre chasm with raw sealant will cause it to sink, slump, bubble, and waste hundreds of dollars in unnecessary product.
Would you prefer to use a flexible silicone that handles structural movement, or a hard epoxy/polymer plug that cures quickly so you can fill the pool sooner? I can give you the exact application steps for whichever method you choose.
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AquaBond AdhesivesFlexible Concrete Crack Fillers – AquaBond Adhesives25 Aug 2026 — What is the best flexible concrete crack filler? The best filler depends on the application. For underwater repairs in pools and s…
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MaxisilSwimming Pool Silicone – Pool Caulking – MaxisilMaxisil Pool is a premium, neutral cure silicone product that is designed for swimming pools. It is available for both domestic an…
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AC PoolsUnderwater Magic Adhesive & Sealant (Grey) – AC PoolsUnderwater Magic Adhesive & Sealant (Grey). UWM 004. Price: $80.95. Available. Buy Now. Underwater Magic™ is an extremely strong s…
how would Drizoro Maxjoint Elastic compare don't have to have a completely dry substrate Tiles are not going to be opened other saw cur to expose and deep the crack
Drizoro Maxjoint Elastic is an exceptional, heavy-duty alternative for this specific situation. In fact, it outperforms standard silicones and epoxies for a concrete, saltwater pool repair because of your two main conditions: you are saw-cutting a deep track and you do not want a completely dry substrate. [1, 2]
Unlike silicones which strictly fail on damp concrete, Drizoro products require a wet substrate to cure. [1]
How Drizoro Maxjoint Elastic Compares
A direct breakdown shows how it compares to your other choices for an open, saw-cut crack:
| Feature | [Drizoro Maxjoint Elastic](https://www.drizoro.com/en/producto/maxjoint-elastic/ “Maxjoint Elastic | DRIZORO”) | Maxisil Pool Silicone | Epoxy Pool Putty |
|---|---|---|---|---|
| Substrate Moisture | Must be damp/wet | Must be completely bone dry | Can tolerate dampness | |
| Saltwater Rating | Excellent (Saline resistant) | Excellent | High resistance | |
| Tile Compatibility | Blends with concrete/tiles | Forms a shiny silicone bead | Forms a rigid, visible plug | |
| Flexibility | 15% joint movement | High flexibility | Rigid (No flexibility) | |
| Application Style | Cementitious 2-part mortar | Standard caulking cartridge | Hand-kneaded clay putty |
Why This Fits Your “No Tile Removal” Approach
Because you are saw-cutting a deep track directly between or through the exposed pool floor/walls without pulling up tiles, Maxjoint Elastic acts like a flexible, waterproof grout. [1]
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- The Wet Substrate Advantage: After saw-cutting and deepening the crack, you must flush out all the concrete dust with water. With silicone, you would have to wait days for that deep cut to dry out entirely. With Drizoro, you can apply it right after washing while the concrete channel is still thoroughly damp. [1]
- Mechanical Lock: Because it is a cement-based compound mixed with synthetic resins, it achieves a high-strength bond that physically locks into the freshly cut concrete walls of the crack. [1, 2]
- Appearance: It cures to a grey matte finish that will blend much better with a concrete or tile-cut finish than a bright or glossy bead of silicone. [1]
Important Application Caveats for Your 15m Crack
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- Do Not Skip the Backer Rod: Even though it is a cementitious mortar blend, for joints up to 10 mm wide, the manufacturer data sheet explicitly states that the sealing depth should be at least half of the joint width. Use a closed-cell foam backing rod in your deep saw cut to maintain correct depth and save product. [1]
- Mixing and Working Time: It is a 2-part kit (Liquid Resin + Cement Powder). Once you mix it to its “toffee-like” consistency, you only have 30 minutes of working time. Mix it in small batches rather than trying to tackle the whole 15 metres at once. [1, 2, 3]
- Curing Time Before Refill: While Maxjoint Elastic Express allows for immersion after 3 days under perfect weather conditions (20°C), standard Maxjoint Elastic can require up to a few weeks for permanent structural submersion. Ensure you pick up the “Express” variation kit if you want to refill the pool quickly to catch the summer heat. [1, 2, 3]
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waterproofingshop.com11 Benefits Of Drizoro Maxjoint Elastic Express11 Benefits Of Drizoro Maxjoint Elastic Express * Allows movement capability of the joint up to 15%. Suitable for sealing expansio…
A 2 kg kit of Drizoro Maxjoint Elastic is almost the perfect amount for your project.
The technical consumption rate for a standard 10 mm wide by 10 mm deep joint is approximately 0.125 kg per linear metre.
Material Breakdown for Your 15-Metre Crack
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- Total required for 15 metres (at 10×10 mm): 15 m × 0.125 kg = 1.875 kg of product.
- Your margin: Buying a 2 kg kit gives you a tiny 125-gram safety margin.
- If you use a backer rod (10 mm wide × 5 mm deep): The consumption drops to 0.065 kg per metre. You will only use about 1 kg of product, leaving you half a kit extra as a buffer for any uneven areas where the saw cut ran deeper. [1]
Product Selection & Pricing
For a rapid turnaround time to use the pool this summer, look specifically for the Express version, which handles permanent immersion much faster.
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- Drizoro Maxjoint Elastic Express (2 kg) retails for around $87 to $98 AUD. This version is highly recommended because it cures rapidly for water immersion in 72 hours.
- Drizoro Maxjoint Elastic Standard (2 kg) sits around $99 AUD. However, the standard formula can require up to 3 weeks to fully cure for total immersion, which will eat into your summer swimming time.
Application Steps for Your Opened Saw-Cut
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- Flush the Track: Use a pressure washer to thoroughly clean out the saw-cut track. Concrete dust will ruin the bond.
- Leave it Wet: Do not dry the concrete. Drizoro requires a thoroughly damp substrate to properly cure and chemically lock into the concrete walls. [1]
- Press the Backer Rod: Push your 10 mm foam backer rod down into the bottom of the cut track so you maintain a consistent 5 mm to 10 mm depth reservoir for the product. [1]
- Mix 1:1 by Weight: This is a two-part kit (Liquid Resin Part A + Powder Cement Part B). Weigh out exactly equal parts of each to mix small batches. It sets fast, giving you only about a 10 to 15-minute working window for the Express version
- Pack & Tool: Pack the mixed mortar tightly into the crack using a small trowel or a sausage/caulking gun, smoothing it flat against the edges of your cut track. [1]
Do you already have a backer rod sorted out, or would you like a recommendation on what size and type to grab along with the 2 kg kit?
