Depending on who you talk to and what type of machine they have will depend on what answer you will get to this question.

When building codes changed from normal 2″x4″ to 2″x6″ construction, normal gutters would not cover these taller rafter tails, so they developed the deeper fascia gutter profile. They do not work nearly as well for several reasons, one it has a narrower bottom to save on sheet metal costs, even after this adjustment a fascia gutter requires 3” more material than a conventional gutter to produce. Gutter contractors found that by going back to using steel versus aluminum they could get the prices closer to the 5K aluminum gutter prices by offering the lower grade material.

The builders liked this as they found out that they could get way with not installing a fascia board at the end of the rafter tails and that if the gutter was made with a flange at the top they could eliminate paying for drip edge as well (more on this later).

Many times fascia gutters are touted as having higher capacity which is partly true, but assuming that you use a fascia gutter with the same size outlet as its 5K counterpart both gutters will jam just as soon, the only difference is the couple of extra seconds it takes for the fascia gutter to fill to the top. The volume of water through the downspout is almost identical as what determines the difference in gutter flow is the size of the outlet and the pitch (angle) of the mounted gutter. As to how fascia gutters function, that is covered in another article.. “Do Fascia Gutters Work?

Fascia Gutter 5″ Modern Profile w/Self Flashed Lip

Fascia Gutter w/Self Flashed Lip

5k Style Gutter Profile