Diamond Basement Waterproofing, a division of Diamond Masonry & Waterproofing, has been servicing Long Island since 2000. Over this time, we have been able to help hundreds of customers solve their basement waterproofing needs. We are a family-owned business, and we operate efficiently without a lot of overhead like many of the larger companies servicing the Long Island market. This enables us to deliver more affordable solutions to our customers. We are proud of our excellent marketplace reputation.