Our company (a modular manufacturer,) will run the vent at the factory through the roof opening to a boot if the vent is located low enough in the roof to come through the fixed portion of the roof at the eave. Installing the portion of the vent stack that sticks up outside the roof is the responsibility of the builder.

Some roofs do not allow factory installation of any part of the vent system in the attic, perhaps because the roof, in shipping position, would crush the material. In those cases, installation is also on-site by the builder.

Other manufacturers may have a different policy, but the two companies that I have worked for do not have the set crew install or connect roof vents. It is the responibility of the builder to do it on-site. The builder may include the installation of roof vents in their contract with the plumber, but in any case, if the manufacturer of your house includes vent installation among the items the builder is responsible for, you should be insisting the builder complete the job.

Unless you contracted separately with the plumber, I would suggest the builder finish the work or force the plumber to do it.

Wayne