If you hear an annoying ‘clonk’ each time you turn on the tap, it might be that a pipe under the house isn’t adequately secured and is thumping against the woodwork. Worm your way under the house (clutching a measuring tape) to the point where you think the noise originates, having previously arranged for a friend to turn the tap on while you’re there. If the pipe moves and rattles you’ll need to hammer a saddle over it to secure it firmly (see illustration, right). Work out how many saddles you might need and measure the width of the pipe so you know what you need at the hardware store.
You could choose to worm your way under there again with a hammer and nails to install them, or you could send your friend in to do the job!
Another cause of noisy pipes could be an airlock in the internal house
system. See 'A spurting unpredictable hot tap'.