We are currently renovating a property and are putting down 12 mm laminate flooring through out. The white underlay is provided for free but the guy in the shop is pushing that roll of gold underlay which works out at 3e a sq yard. Just wondering if it's necessary or what the advantages are? We have 2 toddlers and baby on the way so this flooring is not for the long term, we will hope to replace it when things get a bit quieter around the place!