Yello - Online construction materials store. Why choose YELLO construction materials online? Yello is an online building materials store For SMEs contractors from BUILK.COM that will help increase profits for the construction business with cheaper and faster deals. We have a wide range of products to choose from and has a network of stores nationwide that sell all types of construction materials. Why did we sell at such a good price? We can negotiate prices with manufacturers, major importers, and distributors to bring better price construction materials to you.