Crown @ Roof Eaves

[TSJHD1]

I have custom framing job coming up that has crown molding at the eaves and rakes, and the eaves wrap around onto the gable walls and return. The return is a hip roof. I'm not too familiar with this detail... I think I've done this maybe 3 times overall, and it's been a long time since the last one.

Couple of questions:

Does crown molding have a "typical" spring angle? Iow, don't most crown moldings lie at about X degrees?
If you wanted to, couldn't you adjust that angle to "force" the crown to lie, say, square to the roof plane?

I'm in the process of doing some shop drawings, mainly so I can see for myself how the crown will affect the heel height of the trusses, because the house has different roof pitches. I also want to be able to look at a detailed drawing so I can decide how this will all go together, and in what order. (iow, does the crown have to be installed before the roof goes on... think: drip edge overlapping the top edge of the crown... "rake" crown dying onto the hip roof returns...)

Thanks for any advice, tips, etc!

Tom

[RJCarney]

Re: Crown @ Roof Eaves

Tom-

I did exactly what you are talking about on my house. Unfortunately, I can't go out to shoot some pics for you cause I have to go out through my daughter's room (walk-out roof deck), as she is still sleeping. Check back later this morning for pics.

I have an intersecting gable roof with a 12/12, with cornice returns, and on one side have flanking shed dormers with a 5/12. Before sheathing the roof, I laid out the detail with the fascia, exact crown and metal drip edge to determine the roof sheathing overhang. Installed the fascia, and drip edge, let the roofers shingle, then installed the crown. This way the roofers could do a good job on the returns, then I fitted the crown on the rake to come down onto the shingles of the return. I also held up the crown off the shingles so the crown ends would not wick up water and could better dry out. Anyway sit tight for a while, and I'll get pics posted once "sleeping beauty" has risen.

RJC

[steve demetrick]

Re: Crown @ Roof Eaves

Tom,
A typical spring angle is 38 degrees, but it really depends on the crown. I would suggest picking out the molding before beginning any layout. Here is a profile I designed to lay flat and mimic a crown. If your project has traditional cornice returns, I would stick with a traditional crown. For installation, our order is crown and returns, drip edge, roofing on return, rake crown, drip edge on rake, back to roofing.

[gburnet]

Re: Crown @ Roof Eaves

Steve, that rake crown in your picture has an interesting profile. It almost appears that it has no spring angle. Is this an illusion or reality? I can't recall seeing that profile around here.

[steve demetrick]

Re: Crown @ Roof Eaves

Greg,
It has no spring angle at all, it's just a piece of 5/4 X 4 that I mill with a profile I designed. A lot of the older houses in my town have a similar detail, basically a shadow board with a profile, the common profile is a simple elongated ogee, I dressed mine up to mimic a traditional crown. I was trying to avoid the labor of installing exterior crown as well as the cost of a second knife to make the raking crown profile.
-Steve

[RJCarney]

Re: Crown @ Roof Eaves

Here ya go-

RJC

[RJCarney]

Re: Crown @ Roof Eaves

A couple more

RJC

[David Meiland]

Re: Crown @ Roof Eaves

Crown is good, but those shingle details on your wall are REALLY good.

[TSJHD1]

Re: Crown @ Roof Eaves

As I draw this out in Sketchup, a few things are starting to become evident. A little more info about the roof:

They're all gables (except for the returns, which are hips). The main (gables on the ends of the house) roofs are 7/12, and the front and rear-facing gables are 9/12. Every gable has hip-roof returns.

The eave crown is set at what appears to be the "typical" angle that most crowns sit at, which on the 9/12 roof makes the crown square to the roof plane. So this crown runs across the eaves, turns the corner at the hip roof return, and runs 3', then returns back to the gable.

I'm posting pics of the SU drawing so far. I don't have the hip roof drawn yet, because I'm just trying to "see" how this goes together, so I can get an idea of the best order to build this. (For some reason the crown molding doesn't want to render correctly.) I purposely set the eave crown's topmost edge lower than the top of the sheathing so the drip edge wouldn't cover too much of that vertical face of the crown. That may change.

And the plans show the vertical faces of both the eave and rake crowns in the same plane.

From what I've drawn so far, it's apparent that a small portion of the roof will show just in front of the rake trim, down at the very bottom. (It's where the 2 lines are in #5)

It seems to me the way to go about building this is to just leave off the rake trims and crowns entirely. Build and shingle the returns, flashing up onto the face of the sub-rake, then install the rake trims, allowing them to die right down onto the shingles, then continue shingling the gable roof.

Does that sound right? And do you need a (metal) drip edge? Seems to me I've seen roofs with crown molding at their edges use cedar shingles as the starter course/drip edge.

Tom

[TSJHD1]

Re: Crown @ Roof Eaves

More pics of drawings...

[TSJHD1]

Re: Crown @ Roof Eaves

Last one...

[TSJHD1]

Re: Crown @ Roof Eaves

Thanks for those pics RJ. I was posting and drawing while you put those up.

Tom

[RJCarney]

Re: Crown @ Roof Eaves

Tom

I recommend using the metal drip edge in this case. It hides and helps protect the plywood edge from excessive wetting, and also comes down just a "scosh" to cover the top of crown. I pre-painted mine black and it blends in well with the shadow line of the shingle overhang.

Good Luck,
RJC

[Bill Robinson]

Re: Crown @ Roof Eaves

You know Tom you can use sheet metal or vinyl coil stock to create that detail with less risk of moisture damage to the crown material.

http://www.industrialladder.com/prod...&categoryID=64

[steve demetrick]

Re: Crown @ Roof Eaves

Tom,
I second the metal drip edge. I use the wood shingle drip edge on occasion when installing rods for hanging gutters, but even then the wood shingles go over the metal drip edge and ice and water. The shingles function very well as a drip edge, but they do soak up a lot of water which is no longer compatible with how we build today. If you can, have the drip edge made up in the color of the trim (I have mine made from aluminum coil stock) so that 1. it blends in with the crown, and 2. you can have the bottom of the drip hang cover the crown and overhang an 1/8" to create a secondary "drip edge". Otherwise the water has a greater tendency to climb back up the face of crown. It's hard to see, but this is how we did it in this picture. For proportioning the size of the hipped returns, there is a good description in that book "Get Your House Right" by Marianne Cusate, we didn't get that part right in this case.