Copper Guttering Rivets 3.9 x 11mm (Bag of 100) Descriptions To complement our standard ranges of copper guttering and copper downpipes we also provide all the neccessary ancillary components to ensure your gutter is easy to install and fitted securely. The low modulous silicone we provide has been laboratory tested for a minimum 25 year life. Our verdgris solution must be applied within days of installing your copper rainwater system.