Use PTFE tape properly
10 minutes — the right way to seal threaded fittings
PTFE tape is used on every threaded plumbing connection. Most leaks come from applying it wrong — wrong direction, too few turns, or not stretched in. This guide fixes that.
Last updated: June 2025
Only basic tools needed — most homes already have them.
Part of the Bathroom Renovation project
This is a Phase 2: Plumbing Prep skill in the full bathroom renovation walkthrough.
If you're renovating your bathroom, start here →Before you start
PTFE tape is used on threaded connections only — not on compression fittings (the type with a nut and olive). Check your fitting type before applying tape.
Turn off the water supply before working on any live fitting. Even with the supply off, there will be water in the pipes — have a cloth ready.
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Tools & materials
- ✓PTFE tape— white plumber's tape — the standard roll is fine for most fittings
- ✓Adjustable spanner— to tighten the fitting after taping
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Clean and dry the thread
Before applying tape, make sure the male thread (the one you are wrapping) is clean and dry. Any grease, old sealant, or moisture under the tape creates gaps that the tape cannot fill. Wipe with a dry cloth if needed. Why: PTFE tape fills the micro-gaps between two mating threads. If there is contamination on the thread, the tape bridges over it rather than pressing into the thread profile, and the seal is incomplete before you even start.
Most people get this done in under 5 minutes.
Where beginners go wrong
Winding anti-clockwise. This is the most common mistake. As you screw the fitting on, an anti-clockwise wrap unwinds rather than tightening into the thread. Always wind clockwise as you look at the thread end.
Applying tape to compression fittings. Compression fittings (nut + olive) seal mechanically — they do not have threads that need tape. Adding tape to them prevents the olive from seating correctly and can actually cause leaks.
Too many loose turns. Four or five loose turns of tape is worse than two stretched turns. The tape needs to be in the thread profile, not layered on top of itself.
If it still leaks after taping...
Remove the fitting, clean the thread, and re-tape — do not try to tighten further as this risks cracking the fitting
A fitting that weeps even after correct taping may have a damaged or corroded thread — replace the fitting rather than attempting to patch it
Recommended starter kit
Five tools that cover most home repairs.
- →Adjustable spannerAmazon·Screwfix
- →Screwdriver setAmazon·Screwfix
- →PTFE tapeAmazon·Screwfix
- →Spirit levelAmazon·Screwfix
- →Tape measureAmazon·Screwfix
Want everything in one go? Get it on Amazon
What you just learned
You know how to apply PTFE tape correctly — the right direction, the right number of turns with the right tension. This is the single most-used technique in basic plumbing and will serve you on every water connection you ever make.
This unlocks:
⚠️ Watch out if you rent
Using PTFE tape on a threaded fitting (e.g. re-connecting a tap) is minor plumbing maintenance. In a rented property, keep the water isolated and the scope small — if in doubt, ask your landlord or letting agent first.