I was trying to contact the manufacturer of a building product. He told me he wouldn't sell it to me and that I needed to go through their licensed distributor. I called the distributor and he agreed to get me the product. 

Now, I noticed that the distributor typically works on a contractor basis. This means that he doesn't sell directly to the customer, but acts as an installer. His clients typically order the service to install the product. However, he was fine with me buying the material and installing it myself.

I was wondering if I could have an e-commerce website where I would sell the product directly to the end customers. I would still fulfill the purchase by buying from the distributor, although they would ship to the end user. 

This way, DIYers could purchase it directly without the need to talk to the distributor. I do realize I would need to handle the returns, but my question is: is it legal without consulting it with the distributor?