Sika Pro searches usually lead to Sika’s professional-grade sealants and adhesives, such as the Sikaflex family, which are used to seal joints, gaps and cracks against water. A sealant is a repair and joint product, not a full waterproofing membrane, and prices depend on the cartridge size, the product type and how much work the surface needs (indicative — get itemised quotes).
This guide covers Sika Pro and other water sealants, spray-on and liquid rubber products, shower grout sealers, waterproof paint, and how to waterproof a wall, with the safety and licensing limits you need to know.
Key points
- Sika Pro products and other poly sealants fill joints and gaps, but they do not replace a membrane in a shower, balcony or other wet area.
- Spray-on, liquid rubber and waterproof paint products suit minor repairs and non-critical surfaces, and each has its own surface-prep and cure rules.
- Always use the exact product named for your material, and follow the label and safety data sheet for ventilation, protective gear and cure time.
- For wet areas, balconies and roofs, book a licensed waterproofer or roofer rather than relying on a tube or a spray can.
What is Sika Pro?
Sika is a global construction chemicals company with operations in Australia, and its professional ranges include sealants, adhesives and membranes. Because product names vary, confirm the exact name on the cartridge and read its technical data sheet before you buy.
Think of a Sika Pro sealant as a flexible gap filler that stays elastic after curing so it moves with the building.
- Joint sealing: fills gaps between materials such as window frames and walls, where movement would crack a rigid filler.
- Bonding: some Sika Pro products double as adhesives, so check whether the label says sealant, adhesive or both.
- Surface compatibility: data sheets list the materials a product bonds to, such as concrete, metal, glass or timber.
- Primer requirements: some surfaces need a primer first, and skipping it is a leading cause of peeling.
- Cure and paintability: check how long it takes to skin and cure, and whether you can paint over it.
- Safety data sheet: read it for ventilation and glove advice, and store cartridges as the label directs.
For bonding jobs, see our construction adhesives guide.
Sika Pro vs other water sealant types
A water sealant can be a gap filler, a coating or a penetrating treatment. The best pick depends on the material and whether water is only splashing or sitting against the surface.
| Type | Best for | Strength / limits | Price band |
|---|---|---|---|
| Sika Pro style gap sealant | Joints around windows, flashings and panels | Flexible and strong, but only seals the joint | $$ (indicative — get itemised quotes) |
| Poly sealant (polyurethane or similar) | Exterior joints with movement | Durable, needs correct primer and prep | $$ (indicative — get itemised quotes) |
| Spray sealant or spray on sealant | Quick surface repairs and touch-ups | Easy to apply, thin coat, not a membrane | $ to $$ (indicative — get itemised quotes) |
| Liquid rubber waterproof sealant | Roof flashings, gutters and planters | Flexible coating, needs a clean dry base | $$ (indicative — get itemised quotes) |
| Water proofing paint | Damp masonry that is not under pressure | Cuts absorption, not for wet areas | $ (indicative — get itemised quotes) |
| Silicone or MS polymer sealant | Glass, metal and bathroom joints | Flexible and paintable only if the label says so | $$ (indicative — get itemised quotes) |
| Butyl or bitumen flashing tape | Metal roof laps, penetrations and temporary leak repairs | Sticks well to clean metal, but UV and heat shorten its life | $ to $$ (indicative — get itemised quotes) |
| Penetrating masonry sealer | Brick, render and pavers that soak up water | Breathable, but must be tested on a small patch first | $ to $$ (indicative — get itemised quotes) |
| Shower grout sealer | Grout lines in tiled areas | Reduces staining, never a membrane | $ (indicative — get itemised quotes) |
See our rust converter and protection guide for treating metal before you seal it.
Sika Pro and sealant cost
Sealant is a small cost compared with the repair it prevents, but labour and prep drive the total. Treat every range as a starting point.
| Item | What drives the price | Typical range |
|---|---|---|
| Sealant cartridge, DIY | Product type and size | Low range per cartridge (indicative — get itemised quotes) |
| Spray sealant can | Brand and coverage | Low to mid range per can (indicative — get itemised quotes) |
| Liquid rubber kit | Coverage and coats needed | Mid range per kit (indicative — get itemised quotes) |
| Licensed re-seal of flashings or joints | Access, joint length and prep | Mid range per job (indicative — get itemised quotes) |
| Full waterproofing membrane | Area, prep and licensing | Upper range (indicative — get itemised quotes) |
| Primer, tape and cleaning supplies | Surface type and joint length | Small extra charge (indicative — get itemised quotes) |
| Scaffold or safe roof access | Height, roof pitch and edge protection | Adds to the quote (indicative — get itemised quotes) |
| Rust or damp repairs first | Extent of damage | Varies widely (indicative — get itemised quotes) |
Sika Pro pros and cons
Sealants are quick and cheap, but they have clear limits. Weigh these before you grab a tube.
Pros
- Fast to apply and cheap compared with a full membrane.
- Stays flexible, so it handles small movement in joints.
- Available in ranges for many materials, from metal to masonry.
- Good for resealing flashings and window surrounds.
- Can often be painted once cured, as the label allows.
- Suits DIY repairs on accessible, non-critical areas.
Cons
- Seals only the joint, not the whole surface.
- Fails early if the surface is dirty, damp or unprimed.
- Needs inspection and re-sealing over time.
- Not a licensed waterproofing system for showers or balconies.
- Wrong product choice can stain, shrink or peel.
- Fumes and skin contact need ventilation and protective gear.
How to choose a Sika Pro or other water sealant
The right sealant matches the material, the movement and the exposure. Use this checklist before you buy.
- Identify both surfaces: metal, glass, concrete, timber and plastics all bond differently.
- Check the movement: a joint that opens and closes needs a flexible product, not a rigid filler.
- Read the data sheet: look for compatible materials, primer needs, cure time and paintability.
- Match the exposure: UV, standing water and chemicals each need an appropriate rating.
- Check for wet-area use: only use products approved for the room, and book a licensed waterproofer for membranes.
- Compare supplier advice: ask the supplier to confirm the product suits your job in writing.
Applying Sika Pro and other sealants step by step
Preparation matters more than the product. Follow the label exactly and work in the conditions it allows.
- Read the label and safety data sheet for ventilation, gloves, eye protection and storage advice.
- Clean the joint of dust, oil, old sealant and loose paint, and let it dry fully.
- Prime if required by the data sheet, and allow the primer to flash off before applying sealant.
- Mask the edges with tape for a neat bead, then cut the nozzle to match the joint width.
- Apply a continuous bead and tool it smooth before the surface skins over.
- Remove the tape while the sealant is wet, then let it cure fully before water or paint touches it.
How to waterproof a wall
How to waterproof a wall depends on whether water hits the outside face, soaks through masonry or comes from inside. Find the source before you treat the symptom.
- Find the water source: check gutters, downpipes, flashings and ground levels, because a blocked downpipe often explains a wet wall.
- Fix cracks first: fill hairline cracks with a flexible sealant and repair wider cracks with a suitable masonry product.
- Use a breathable masonry sealer: choose a water sealant made for your wall type, and avoid trapping moisture inside brick or render.
- Re-seal joints and penetrations: windows, pipes and vents are common entry points for water.
- Finish with paint: choose an exterior system compatible with the sealer, and see our Lexicon Quarter vs Half vs Full guide for white choices.
- Know the limits: if water is coming through a retaining wall or below-ground wall, book a licensed waterproofer.
Spray on waterproof sealer and water proofing spray
A spray on waterproof sealer is the fastest way to coat a surface, but the film is thin. It suits touch-ups and low-risk areas, not wet-area membranes.
- Surface prep: clean and dry the surface fully, because spray over dirt or damp will not bond.
- Good uses: small leaks in gutters, metal joins and non-critical outdoor items where water just runs off.
- Coat count: apply the number of coats the label states, allowing each to dry first.
- Ventilation: spray in open air or a well-ventilated space, wearing the respirator and eye protection the label requires.
- Bad uses: showers, balconies and roofs over living spaces, where a licensed membrane is needed.
- Pets and children: keep them away during application and curing, and call your vet immediately if a pet licks a product.
Liquid rubber waterproof sealant, DIY and liquid seal products
Liquid rubber waterproof sealant products cure into a flexible coating and appeal to DIYers. Treat a liquid rubber DIY waterproof sealant as a repair product, and read the data sheet for what it can handle.
- Roof flashings and gutters: useful for resealing small leaks on accessible metal, once the area is clean and dry.
- Planter boxes: check the maker allows contact with soil and water before you rely on it.
- Liquid seal products: the term covers many chemistries, so read the label rather than going by the name.
- Roof sheeting: do not seal polycarbonate or other sheeting unless the maker approves, as some sealants attack plastic; see our polycarbonate roofing guide.
- Wet areas: do not treat a liquid rubber kit as a licensed shower or balcony membrane.
- Roof access: roof work is high-risk, so book a licensed roofer if you cannot reach the leak from a safe, stable position.
Shower grout sealer, Aquamix Sealers Choice Gold and Flex Seal Clear
Grout sealers and clear sealers protect surfaces from stains, but they do not stop water coming through a failed membrane. Check each product’s intended material and local availability.
| Product type | What it does | What to check |
|---|---|---|
| Shower grout sealer | Reduces grout absorption and staining | Apply to clean, dry grout only, and recheck after cleaning |
| Aquamix Sealers Choice Gold | Penetrating sealer for stone, tile and masonry surfaces | Confirm it suits your stone type and finish on the data sheet |
| Flex Seal Clear | Clear liquid rubber sealant sold for small repairs | Check availability and suitability for your surface before use |
| Water proof sealer for masonry | Repels water on brick, render and pavers | Test a small area first to check for darkening |
| Silicone bathroom sealant | Seals corners and joints in wet areas | Use a sanitary-grade product, and replace when mouldy or cracked |
| Waterproof membrane | Stops water passing through the floor or wall | Applied by a licensed waterproofer, never a sealer |
For lining options in wet rooms, see our internal wall cladding ideas and WPC composite cladding guides, and read insulation types to understand moisture in walls and roofs.
Common Sika Pro and sealant mistakes to avoid
- Sealing over dirt or damp: the sealant skins over but never bonds, so clean and dry the joint first.
- Choosing the wrong product: one that attacks plastics, stains stone or will not stick to the material can make things worse.
- Using sealant as a membrane: showers and balconies need a licensed waterproofing system.
- Skipping primer or the cure time: both are on the data sheet for a reason, and rushing leads to failure.
- Ignoring ventilation and PPE: fumes and skin contact are real risks, so follow the label and safety data sheet.
- Burying a leak: sealing the surface without finding the water source hides the problem until it returns.
Sika Pro and water sealant FAQs
What is Sika Pro used for?
Sika Pro searches usually point to Sika’s professional sealants and adhesives, used to seal joints and bond materials. Exact products differ in what they stick to and how they cure. Check the data sheet for compatible surfaces, primer needs and paintability before buying.
How to waterproof a wall?
First find where the water comes from, then fix gutters, flashings and cracks. Apply a breathable masonry sealer or suitable coating made for your wall type, following the label. If water comes through a retaining or below-ground wall, or the wall is in a wet area, book a licensed waterproofer.
Is liquid rubber a proper waterproofing membrane?
Liquid rubber products can seal small leaks and flashings, but they are not a replacement for a licensed wet-area membrane. For showers, balconies and rooms below, book a licensed waterproofer who follows the relevant Australian Standard and provides a certificate of compliance.
Is waterproofing paint worth using?
It helps on damp masonry that is not under water pressure, because it reduces absorption. It will not stop a leak or replace a membrane. Use it as part of a system after fixing the water source, and follow the label for surface prep and coats.
Can I use a spray sealant on my roof?
For small repairs on metal flashings, perhaps, if the label allows and you can reach the area safely. Roof work is high-risk, and many leaks come from fixings or laps. Book a licensed roofer to find the cause and make a lasting repair.
Is shower grout sealer enough to stop leaks?
No. A grout sealer reduces staining and absorption, but the waterproofing sits under the tiles in a membrane. If you see damp, mould or loose tiles, the membrane may have failed. Book a licensed waterproofer to inspect the shower.
Getting sealing and roof repairs done in Sydney
Sika Pro and other sealants work best when the leak is found first and the surface is prepared properly. We coordinate licensed roofers and painters across Sydney for flashing repairs, resealing and waterproofing, with itemised quotes and workmanship cover. Book a free roof repair quote.
