When replacing roof fascia boards, is it common or required to re-nail the roof decking into the new fascia? My contractor says this is not necessary because the decking is nailed to the rafters about 6" in from the edge, but after he did this job I'm seeing several gaps between the roof decking and the fascia. These gaps are mostly about 1/4" but up to 5/8" in some places. I'm concerned about water coming in during high winds, or the wind picking up the edge of the roof. My roof is made of roll roofing with metal drip edge. So I see three options:

  1. Leave the gaps with no nails.
  2. Peel up the roofing, nail it down, and re-torch.
  3. Nail through the roofing and dab with caulk. I would be concerned about water leaking around the nails.

enter image description here

  • 1
    How about a picture looking at the outside portion and the 5/8" gaps?
    – JACK
    Commented Dec 5, 2022 at 20:38
  • 1
    How did that gap look on the old fascia? Did the old fascia have an angled cut to compliment the angle of the roof? If you want then test out your rain theory with a garden hose.
    – MonkeyZeus
    Commented Dec 5, 2022 at 20:46
  • @MonkeyZeus good question. Unfortunately it's already been hauled away but I'm guessing it did have a beveled edge because I never saw a gap before.
    – Elliott B
    Commented Dec 6, 2022 at 0:10
  • 1
    I see you've edited the picture and I see no daylight coming through so that's at least good. If the edge of the roof has a proper drip-edge then you should have zero functional issues; the vanity issue will remain though. The contractor should have put an angle on that board but I guess they didn't want to spend the time or didn't have the proper tool on-hand.
    – MonkeyZeus
    Commented Dec 6, 2022 at 0:22
  • @MonkeyZeus, no roof I've ever worked on (of many hundreds) has had beveled fascia. It's not a useful thing, in my opinion.
    – isherwood
    Commented Dec 6, 2022 at 16:07

1 Answer 1


Roof sheathing is not normally nailed to finish fascia to begin with*. This is because the fascia isn't always up tight to the sheathing**, and nailing it down would create dips. This is especially true when replacing legacy lumber with modern, nominally-sized boards, which tend to be smaller.

Depending on how the sheathing was installed (with enough fascia lap or not), it could be nailed to subfascia (the framing behind the finish fascia) without issue.

But, in general, no. The drip edge should adequately handle water drainage in conditions short of a hurricane. A seal between wood components isn't critical.

* It was sometimes done way back, when all roofs were hand-framed and often had open soffits. It's not common anymore.

** Wood being wood, and humans being humans, there's always some variation in the height from the bottom of the fascia (or soffit) and the top of the rafters. This is normalized at the bottom of the fascia, where a consistent margin below the soffit is established, leaving some variation between the top of the fascia and the top of the rafters. This is normal and almost unavoidable.

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service and acknowledge you have read our privacy policy.

Not the answer you're looking for? Browse other questions tagged or ask your own question.