Which tape should I use for which job?

Tape is bought by appearance and fails by chemistry. The adhesive, the backing and the intended surface all differ, and the reason a repair peels in a fortnight is usually that the tape was never meant to do it.

Step by step

1. Use masking tape for paint lines only.Low tack so it lifts cleanly. Get low-tack or delicate-surface grade for fresh paint and wallpaper. It is not a fixing tape and it holds nothing.
2. Remove masking tape while the paint is still wet.Or within a day at most. Left for a week, especially in sun, the adhesive bonds and takes the paint with it — which is the single most common tape mistake in decorating.
3. Treat duct tape as temporary.Strong and grippy, and the adhesive degrades with heat and time into a sticky residue that is miserable to remove. Excellent for bundling, holding something while glue sets, or a roadside repair. Not for anything permanent, and not on paintwork.
4. Never use duct tape on ducting.It fails on the temperature cycling of actual ducts. Foil tape is what ducting needs, and it is what the name unhelpfully implies duct tape is for.
5. Use PTFE tape on threaded plumbing joints.Wrapped clockwise around the male thread, three or four turns, in the direction the fitting will tighten. It seals the thread. It does nothing on a compression joint or a push-fit, where the seal is a washer or an O-ring.
6. Use self-amalgamating tape where it must stay watertight.It fuses to itself into a solid rubber sleeve with no adhesive at all. Stretched hard as it is wrapped. The right answer for a hose, a temporary pipe repair or an outdoor cable joint.
7. Use electrical tape for insulation, not for joining.PVC tape insulates and identifies. It does not make a mechanical connection, and a taped-together electrical joint is not an acceptable repair — that needs a proper connector.
8. Use double-sided tape by weight rating.Foam mounting tapes carry a stated weight per length. Clean both surfaces with alcohol first, press firmly for thirty seconds, and expect full strength after a day rather than immediately.
9. Use foil tape for heat and vapour.Aluminium tape for ducting, insulation seams and anything warm. It handles temperature and forms a vapour barrier, neither of which cloth tape does.
10. Use gaffer tape where residue matters.Cloth-backed and matt, and it removes far more cleanly than duct tape. More expensive, and worth it on floors, cables and anything that will be lifted again.
11. Match the tape to the surface, not just the job.Textured wallpaper, fresh paint, rough masonry and powder-coated metal all defeat ordinary tapes. Surface preparation and the right grade matter more than the brand.
12. Store tape somewhere cool.Adhesive degrades in a hot loft or a cold shed. A roll that has been in a van for two summers will not hold what it should.

Tips

• Buy masking tape in two grades — standard and low-tack. The delicate one costs a little more and saves a wall.
• Warm tape with a hairdryer before removing it from a painted surface. It releases far more cleanly.
• For a leaking pipe, self-amalgamating tape plus a jubilee clip holds until a plumber arrives. Duct tape does not.

Common mistakes

• Using duct tape as a permanent repair — The adhesive breaks down with heat and time, leaving a residue that is very hard to remove and a repair that has already failed.
• Wrapping PTFE tape the wrong way — Wrapped anticlockwise it unwinds as the fitting tightens and seals nothing. It goes clockwise, in the direction of tightening.

If it doesn't work

Questions people ask