Calder Introduces the Borra Fixing Clip The answer to fastening Lead Flashing By Anne Macdonald For busy lead installers, time is money.  These easy to use fixing clips will result in time saved. Using the Clip will securely fasten Lead Flashing in place in accordance to BS6915.  The Standard recommends that fixings are fixed at 450mm maximum centres. Available in packs of 25 from your local Calder stockist.