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Community and Q&A

Fascia details

ForensicGeologist | Posted in Green Building Techniques on

We have a 1969 house in Tallahassee- a tree fell on our house during Hurricane Michael  6 months ago and we have finally made it through the all red tape to begin our reconstruction which we are doing ourselves. The roof is 4:12 gable roof with asphalt shingles which we are going to re-roof with architectural shingles. The original half of the house has 2×4 rafter tails cut square and the previously remodeled half has 2×4 rafters with plumb cut tails. We are going to cut all the tails plumb and replace all fascia and vent the soffits prior to the re-roof. The current fascia is 1×8 pine and has 1×2 double fascia at the top of the fascia board behind the drip edge and gutters on the eaves. I have a few questions regarding the fascia details and have not been able to find the answers here, at FineHomebuilding or elsewhere.

1. I cant find any answer to when sub-fascia is needed or what it’s purpose is. Can you all tell me when and why?
2. Is the 1×2 double fascia on top of the fascia and behind the drip edge necessary? I feel like this is a belt and suspenders approach and might be unnecessary if the drip edge is installed properly.
3. I plan to use new 1×8 wooden or fiber cement fascia. Would you all recommend either of these or something different?

I look forward to hearing your thoughts on these details.


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  1. Expert Member


    1. The sub-fascia (or rough-fascia) is part of the framing. It supports the roof sheathing at the eaves, and provides backing for the gutters. That said, many older houses, or those with exposed rafter tails, don't have a rough fascia.

    2. No the 1"x2" isn't necessary, and is probably a regional thing . The only time I've seen it here is on eaves with no gutters as a purely visual element.

    3. I would recommend no finished fascia, and suggest using a pre-finished 5" fascia-gutter attached to a 2"x4" sub-fascia instead. Unless a substantial fascia is a necessary part of the house style, it's just one more thing to maintain - and only a small part of the bottom shows.

  2. Expert Member
    Peter Yost | | #2

    I think we need to make sure we are all using the same terms in the same way:

    1. Tripp - you say you have two fascia trim boards: one is 1 by 8 and the other is 1 by 2.
    2. Malcolm - you introduce the terms sub-fascia and rough fascia as rough lumber interior to the trim fascia. I don't think that this is what Tripp has or is talking about.

    Any trim fascia is just that: trim. It's main function is aesthetic. When the trim fascia is as wide as a 1 by 8, some folks feel the need to "break up" that wide of a single plain and so a second, shorter trim fascia is introduced to visually break up the "wide" 1 by 8. It's just an architectural detail.

    Much of this aesthetic is made moot by a gutter, which hides much of the fascia detail, including that wide 1 by 8. This is why some architects hate gutters: they block all the cool-looking trim at the roof eaves.

    Stacking trim fascia can affect the relationship between the drip line of the roof/drip edge and the gutter. You absolutely need a metal drip edge and it should relate to the gutter in such a way that regardless of the pitch of the roof and how much water is streaming off the roof, most if not all of it lands in your gutter.


    1. Expert Member
      MALCOLM TAYLOR | | #3


      I'm not sure there is any confusion. The "sub-fascia" comes up in Tripp's first question. That's why I address it. He asks what they are for and whether he needs one in addition to his existing trim fascias.

      He then asks if the smaller 1"x2" on his existing fascia is necessary if you have a drip edge.

      His third request is for other suggestions.

  3. user-6184358 | | #4

    The cement board facia will needed a 2x subfacia support.Look at the mfg details.

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