Who makes or supplies Cellar bulkhead Fiberglass doors?

There is a US patent for a Fiberglass Bulkhead Basement Door, (see patent number 5,600,921). The original prototypes were made in China and could be sold at a retail price competitive to steel bulkhead doors. The original company was called the Better Bulkhead Company and was the first inventor of the product.

There is a USA made high performance fiberglass bulkhead cellar door available from Clam Door. The door is ideal for corrosive coastal locations. The unit is available at a premium price.