Joining liner with tape can work but the joint need to be well made, BONE DRY and clean during the making and BONE dry, I use a hairdryer bought specifically for the purpose, blowlamps etc are too hot.
Also some plant roots will grow through the tape, I have had this happen on 3 occasions in my stream, tape is also quite expensive. £1.5 a 'metre' for 2" wide is the cheapest I have found and that was buying by the roll, you will probably waste half of it especially if you have folds to deal with.
Of course the possiblity also exists that a joint will fail but at least you would only loose a little water.
Honest answer, totally re line and use the old liner for something else DO NOT leave it is situ, left in situ it will act as a water trap and a 'hard' surface against which grains of sand, trapped between the two liners, can push and endanger the new liner.
Posted on Aug 19, 2005, 11:26 AM from IP address 84.68.175.32