Which sealant or adhesive do I need?
Short answer: match the product to the job — silicone for waterproof gap-sealing, polyurethane (PU) for flexible structural bonds, contact adhesive for large surfaces like laminates, a specialist glue for wood or tiles, and PTFE tape for sealing threaded plumbing joints. This guide walks through each type, what it’s best at, and how to pick the right one the first time.
Walk down the adhesives aisle and it’s easy to grab the wrong thing. The trick is to think in categories: are you sealing a gap, bonding two surfaces, or sealing a thread? Each has a best-fit product, and using the right one is the difference between a repair that lasts and one you’re redoing next month.
Sealants vs adhesives vs tapes: the quick map
| Type | Best for | Notes |
|---|---|---|
| Silicone sealant | Waterproof sealing of gaps — baths, showers, windows, kitchens. | Flexible, waterproof, mould-resistant grades available; not usually paintable. |
| Acrylic sealant | Filling cracks in walls before painting. | Paintable, but less flexible and not for constant wet areas. |
| Polyurethane (PU) sealant/adhesive | Flexible, strong structural seals & bonds that take movement. | Paintable, very tough, great for outdoor and construction joints. |
| Contact adhesive | Bonding large flat surfaces: laminates, veneers, rubber, leather. | Coat both sides, let tack off, then press — instant grab. |
| Wood glue (PVA) | Joining timber & boards. | Clamp while it cures; interior vs exterior grades. |
| Cyanoacrylate (super glue) | Fast small repairs on tight-fitting parts. | Products like Q Bond add a filler powder for gap-filling strength. |
| PTFE / plumber’s tape | Sealing threaded pipe joints. | Wrap the male thread; seals against leaks under pressure. |
Silicone vs acrylic vs PU: which sealant?
- Choose silicone when it must stay waterproof and flex — around baths, basins, showers, sinks, and window frames. Use a mould-resistant grade in bathrooms.
- Choose acrylic when you’ll paint over it — filling skirting gaps and wall cracks indoors before decorating. Don’t use it where it stays wet.
- Choose PU when the joint moves or carries load and needs to be tough and paintable — expansion joints, outdoor seals, bonding where you want real strength.
Browse silicone sealants and the full Adhesives, Sealants & Tapes range, with trusted brands like Soudal and Bostik.
Which glue for which material?
- Wood — a quality wood glue (PVA); use exterior grade outdoors and clamp until cured.
- Laminates & large surfaces — contact adhesive (e.g. Genkem); coat both faces, let them go tacky, then press firmly.
- Tiles — the right tile adhesive for the surface and tile type.
- Metal, ceramic & quick fixes — a two-part epoxy or a Q Bond super-glue-and-filler kit for strong, fast repairs; Pratley for tough structural bonds.
- “No more nails” jobs — a grab adhesive (like Pattex) to mount without drilling.
How to use PTFE (plumber’s) tape
PTFE tape seals threaded plumbing joints so they don’t weep under pressure:
- Start a couple of threads back from the end of the male fitting.
- Wrap in the same direction the fitting will screw in (usually clockwise, looking at the end), so tightening doesn’t unravel it.
- Wrap firmly, overlapping, about 4–6 turns, pulling it into the threads.
- Screw the joint together as normal and tighten.
Grab a roll of PTFE plumbing tape, or see all tapes for duct, masking, double-sided and electrical jobs.
Tips for a bond that lasts
- Clean and dry first. Dust, grease and damp are the enemy of adhesion — wipe surfaces down and let them dry.
- Respect the cure time. Grab is not full strength; leave sealants and glues to cure fully before stressing the joint.
- Tool silicone neatly with a wet finger or a sealant tool for a clean, watertight line.
- Match flexibility to movement. Rigid glue on a moving joint will crack — use a flexible sealant or PU where things expand and contract.
Frequently asked questions
What is the difference between silicone and acrylic sealant?
Silicone is flexible, waterproof and ideal for wet areas like bathrooms and kitchens, but it generally can’t be painted. Acrylic sealant is paintable and good for filling wall and skirting cracks before decorating, but it’s less flexible and not suited to constantly wet areas.
Which glue is best for wood?
A quality PVA wood glue is best for joining timber and boards — use an exterior (waterproof) grade for outdoor work and clamp the joint until it cures. For bonding wood to other materials, a PU adhesive or grab adhesive may work better.
What is contact adhesive used for?
Contact adhesive is used to bond large flat surfaces such as laminates, veneers, rubber and leather. You coat both surfaces, let the glue become touch-dry (tacky), then press them together for an instant, strong bond — there’s no repositioning afterwards, so align carefully.
Which way do you wrap PTFE plumber’s tape?
Wrap PTFE tape around the male thread in the same direction the fitting screws in — usually clockwise when looking at the end of the pipe — so tightening the joint pulls the tape in rather than unravelling it. Four to six firm, overlapping turns is usually enough.
What is the best sealant for a bathroom or shower?
A mould-resistant silicone sealant is best for bathrooms and showers because it stays flexible and fully waterproof and resists the mould that thrives in damp areas. Make sure the surface is clean and completely dry before applying, and tool the bead smooth for a watertight finish.
Still not sure which product to use?
Tell us what you’re bonding or sealing and we’ll recommend the right product and brand. Browse the full Adhesives, Sealants & Tapes range or contact the Securadeal team.
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