Types of waterproofing chemicals, explained in plain words
Shops and quotes use brand names, which hide what is actually in the bucket. Underneath, almost every waterproofing product belongs to one of a few families. Knowing the family tells you where a product can work, what surface it needs, and how it can fail. This guide explains each family without naming brands.
Quick answer
What are the main types of waterproofing chemicals?
The common families are: flexible cementitious coatings (bathrooms, tanks, slabs under tiles), acrylic elastomeric coatings (exposed terraces and outside walls), polyurethane membranes (demanding roofs and moving surfaces), bitumen products (roofs and below-ground), crystalline coatings and admixtures (concrete under water pressure), epoxy grouts and coatings (tile joints and chemical resistance), SBR or acrylic latex (bonding and mortar modifiers) and injection grouts (active leaks and cracks).
Published
Part of the how waterproofing is done guide, which covers every usual source.
This guide is for you if
- A shop or contractor named a product and you want to know what it is
- You are comparing quotes with different materials
- You want to know which family suits your surface
The main families
Each family has a place. None works everywhere.
Family 1
Flexible cementitious coatings
Two-part polymer-modified cement slurries, brushed or troweled on concrete and masonry.
Where it usually fits: Bathrooms and wet areas before tiling, water tanks, basements, and new slabs that will be covered.
Watch out for: Mostly meant to be covered or protected. Needs a damp but sound, clean surface and the stated coats.
Family 2
Acrylic elastomeric coatings
Thick, stretchy liquid coats, often white or light-coloured, rolled on.
Where it usually fits: Exposed terraces over a sound finish, and outside walls.
Watch out for: Needs a dry, sound surface and periodic recoating. Not suited to standing water for long periods unless rated for it.
Family 3
Polyurethane (PU) membranes and sealants
Rubbery liquid membranes or gun-applied joint sealants.
Where it usually fits: Roofs with movement or many details, moving cracks and joints.
Watch out for: Needs a dry surface and skilled application. Some types need a UV-resistant top coat in sun.
Family 4
Bitumen products
Sheet membranes laid with heat or self-adhesive, or bitumen-based liquid coats.
Where it usually fits: Large roofs, foundations and below-ground surfaces.
Watch out for: Overlaps and edges are weak points; exposed bitumen ages in sun unless protected.
Family 5
Crystalline coatings and admixtures
Cement-based coats or additives whose chemicals grow crystals inside concrete pores.
Where it usually fits: Concrete tanks, basements and structures under water pressure, often from the inside face.
Watch out for: Works on concrete, not on brick or plaster. Does not bridge moving cracks.
Family 6
Epoxy grouts and coatings
Two- or three-part resin systems, very hard and chemical resistant.
Where it usually fits: Tile joints in bathrooms and kitchens, industrial floors and chemical areas.
Watch out for: Rigid. Not a membrane for surfaces that crack and move.
Family 7
SBR or acrylic latex bonding agents
Milky liquids mixed into cement mortar or used as bonding coats.
Where it usually fits: Improving bond and water resistance of plaster, repair mortar and screeds.
Watch out for: A modifier, not a waterproof membrane by itself.
Family 8
Integral waterproofing admixtures
Powders or liquids added to concrete or plaster while mixing.
Where it usually fits: Reducing water absorption of new concrete and plaster.
Watch out for: Helps the mix, but does not seal cracks that form later. Not a substitute for a membrane where one is needed.
Family 9
Injection grouts (PU, acrylic, epoxy)
Resins pumped into cracks, joints and voids through small ports.
Where it usually fits: Active leaks in basements and tanks, isolated drip points, and structural crack repair (epoxy).
Watch out for: Stops the leak at that point. The wider surface may still need waterproofing.
Methods follow proven, manufacturer-approved waterproofing systems. The right one for your building depends on what is found on site.
What a photo can and cannot tell you
Photo guidance points to the likely source. It is not a confirmed diagnosis.
A clear photo can show
- The surface and whether it is exposed
- What finish is on it now
- Visible cracks and details
A photo cannot settle
- Which product was used before
- Whether old layers are still bonded
- Moisture inside the surface
Simple checks before you call anyone
- 1Look up the family of any product you are quoted (it is on the data sheet).
- 2Check whether it will be exposed to sun or covered.
- 3Check what surface it needs: concrete only, dry, damp, or over tiles.
- 4Ask for the coverage per coat and number of coats.
When you need someone on site
- Contractors are proposing different material families
- An earlier system failed and nobody knows what was used
- The surface is under water pressure or chemical exposure
A site diagnosis helps check the likely source. For hidden or recurring leaks, thermal imaging and moisture checks can help narrow down the water path before deciding whether anything needs opening up. In Vadodara? See leak detection and waterproofing help in Vadodara for site services, coverage and contact options. The app confirms availability at your building's pincode before you book.
Common mistakes that waste money
- Choosing by brand or price without knowing the family.
- Using a coating meant to be covered on an exposed terrace.
- Expecting a rigid material to bridge a moving crack.
- Treating an admixture or bonding agent as a complete waterproofing system.
Before you accept a contractor's quote
- Does the quote name the material family, not only a brand?
- Does it match the family to your surface and exposure?
- Does it give coverage, coats and area?
- Does it explain what protects the layer afterwards?
Already have quotes? Membrain can compare them on scope, not just price. Planning the work instead? A written specification makes quotes comparable.
How this guide is built
Diagnostic basis
Membrain separates visible signs from possible water-entry mechanisms, then asks for evidence that can distinguish the remaining causes.
Repair-source governance
Public guides stay brand-neutral. When Membrain creates a repair plan, methods and products come from current approved manufacturer documents in its technical library.
Evidence limits
A photo cannot confirm concealed pipes, waterproofing layers or moisture depth. When remote evidence cannot separate the causes, a site inspection is the correct next step.
Waterproofing chemical kitne prakar ke hote hain?
Brand naam alag-alag hote hain, par andar zyada tar ek hi family hoti hai: cement wala flexible coat, acrylic elastomeric coat, PU, bitumen, crystalline, epoxy, latex aur injection grout.
Har family ki apni jagah hai. Jo coat dhakne ke liye bana hai, wo khuli chhat par nahi chalta. Rigid material hilti darar par nahi tikta. Data sheet par family zaroor dekho.
Frequently asked questions
What are the names of waterproofing chemicals?
By family: cementitious coatings, acrylic elastomeric coatings, polyurethane membranes and sealants, bitumen membranes, crystalline products, epoxy grouts, SBR or acrylic latex, integral admixtures and injection grouts. Brand names sit inside these families.
Is waterproofing paint the same as waterproofing coating?
Not always. Many exterior paints only repel water. A waterproofing coating is applied thicker, stretches over hairline cracks and is meant to stop water under exposure. Check the data sheet.
Which waterproofing chemical is used for walls?
For outside walls, crack filling followed by a flexible exterior waterproof coating. For damp at the base of walls, a cementitious or other barrier behind new plaster. The source of the damp decides it.
Is liquid waterproofing better than sheet membrane?
Liquids are seamless and easier around details. Sheets give uniform thickness over large areas. Each suits different roofs and applicators.
Let the surface pick the family
Share a photo and answer a few questions. Membrain's free plan suggests the method and material type for each surface, labelled as remote guidance, and the checks a good job should include. Site visits and verified partners are in Vadodara only for now.
Remote guidance, not a site inspection.