Gutter Attachment – Into truss tails required?
wood0619
| Posted in Building Code Questions on
I have a contractor saying gutter attachment does not need to be into rafter /truss tails. I have trusses 24 OC. This seems risky not to fasten them into the tails and only into the fascia board. What is correct best practices? In Minnesota where ice dams are possible.
Thanks!
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You can attach gutters directly to fascia boards, as long as you don't mind redoing them every few years. Best practice is to have a 2X sub-fascia, though many builders omit it to save money. But it makes things like installing gutters a lot easier.
You can use brackets that attach to the roof surface. They aren't ideal but they work.
Michael,
Another regional difference I guess. Here all trussed roofs have a 2x4" sub-fascia, and the bottom edge of the roof sheathing gets nailed to it. Many houses, like my own, have no finished fascia, but use 5" deep fascia-gutters instead.
Malcolm, the first time I had seen a sub-fascia was when I worked in Seattle as a carpenter in 1996. I've always used them since then, and usually show them on drawings, but it's something builders often omit. I've never used gutters with integral fascia--are they sloped or level? I know that in theory you can install gutters perfectly level, but I have only seen them installed with a slope.
Michael,
To be clear, a fascia-gutter is just one that is deep enough to cover the sub-fascia and soffit behind.
We get a lot of rain here, but almost no one slopes gutters. It does mean you are more likely to have some standing water in the bottom, but I think the benefits of level gutters outweighs that.
- Even with a minimal 1/8" per foot slope, a 30 foot gutter would be 4" lower at one end.
- That means there would be a 4" gap between the edge of the roofing above and the top of the gutter, and no consistent relationship with the drip-edge - and that to me is one of the important relationships to get right.
- I've never seen a gutter problem associated with them being level. They clog due to debris, and a slope doesn't help prevent that.
- Aesthetically it disrupts the crisp vertical and horizontal elements of the exterior. Imagine my house with those gutters sloping, rather than straight.
That all makes sense, Malcolm. Due to heavy sliding snow, especially with metal roofs, in the northeast US we try to put gutters below the plane of the roof. We have a lot of relatively steep roofs, so that can put the gutter pretty far below the drip edge.
Micheal,
Yeah well, you guys strap your ceilings, so there really isn't any hope for you :)
Malcolm, I've found that sloped gutters tend to glog the transition fittings to downspouts more quickly, but level gutters get a more evenly distributed layer of gunk. Either way you end up with clogs, but with sloped gutters, the clog is often only in one spot. I suppose that's a bit of a plus for sloped gutters, but if you slope them the recommended amount, they all look "broken" from the yard.
A deeper gutter is probably a good compromise, since it while it can carry a bit less water than a sloped gutter due to flow velocity, more water can "fit" in it so you end up in about the same spot at the end. A good intake screen can solve the clogged downspout issue, or at least make it less frequent.
Bill
Thanks for the great details. My contractor has agreed to fasten the gutter into each truss. It does concern me that this was not the original plan.
These are 5" K-style gutters. Is there a specific hanger you recommend?
ICC code doesn't say anything about securing, only slope. Manufacturer instructions (for amerimax gutters) just say every 24". But I bet putting it through the fascia and into rafter tails would be stronger!