How to turn/finish edge on mansard roof
clarkster75
| Posted in Construction Techniques on
Since the place i’m moving to needs a new roof, I would like to use thicker architectural shingles on the mansard roof, but how do you get the shingles to bend and/or look good where the first slope meets the second slope. The higher shingles will want to stick straight out and not curve down to “blend-in” with the shingles on the second slope.
Is there a type of flashing (matching color I hope) that makes this transition look a bit cleaner?
I want to stay away from the thinner 3 tab although they are on the house now and the transition looks a lot more molded/curved like it was form-fit.
Any suggestions?
Also, if they dont bend down to fit I hope that water/wind doesn’t lift them up and get under the lower course.
Thx.
Replies
I think if you try to start bending shingles your asking for trouble. I have a gambrel roof, similar in that you have a roof slope change. Where the roof slope changes I actually treated it as if it were a roof edge and put down a drip edge that was color matched to the shingles. I flashed the more vertical portion behind the drip edge and then shingled over top.
You said mansard, but gambrel is the style you seem to be describing. Barn style, right?
either way, you can stop, cut, re-trim with fascia or just with shingle drip edge and begin again as a new roof lapped out over the old.
or you can warm the shingles up and turn them over.
If you run the search, under "gambrel" you might find some previous comments and photos.
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I was wondering the same thing thats why I described my Gambrel. Isn't a mansard roof what a lot of the Italianate style homes have. Is the top part of that type of roof flat or does it have some slope? Just curious.
Since i'm pretty wet behind the ears, I looked it up in my construction dictionary.
Gambrel: 2 slopes of gable
Mansard: 2 slopes of hip
My roof is 100% mansard and it originated in France, so says the book, and theres no flat spot at the top, just a ridge.
thx for the input, too
Edited 9/15/2004 3:22 pm ET by clarkster75
pix would help here
Have you considered putting on a traditional metal roof on that Mansard instead of asphalt shingles? That would be the best solution IMO. If Greencu would stop by this thread, he could give you the low down on the best style and way to do it.
If you must stay with asphalt shingles, the two previous suggestions to treat the upper and lower sections as separate roofs are the way to go. I put a gambrel on my place and ran the roof decking 3" past the edge of the joint between the upper and lower roofs as a weather lip. No fascia required, just a drip edge. You could do the same once you strip your roof to reshingle. It makes the detail sharper.
Dinosaur
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Most traditional Mansard roofs I've seen in Paris and New England have, or had, slate roofs. Not saying I don't like metal roofs, that's just what I've seen.
I've got no argument with slate, either: it's gorgeous and I'd love to be able to afford it on my place. But it cannot generally be laid on as an alternative to existing asphalt shingles unless the roof framing was originally conceived and built to handle that kind of weight.
There are several styles of metal roofing used here on Mansards that are appropriate and elegant on the curves these roofs often have. I don't think there are any 'native' slate roofs in this area (no slate in the ground, for one thing--it's all granite up here). But remember that the oldest houses in Québec date from the late 1600s; whereas in France there are some places still standing from dang near a thousand years ago.
Dinosaur
'Y-a-tu de la justice dans ce maudit monde?
No matter what the roof material, this type of roof has to be treated just like what it is - two separate roof planes. One stops, another starts. There's many ways to address the transistion. I normally would shingle up to the transistion and then install a flashing with about a 5" apron to cover my last course nails and then start shingling again on the upper plane.
I agree; that's pretty much what I've been suggesting. And I'm glad you stopped into this thread; I've got a question for ya myself.
There's a style of metal roofing used on the older places up here, but I don't know the name in English. It consists of 'shingles' made of sheet metal, each about 2' x 2' or a bit larger, and they're laid with the corners up and down, like a diamond in a deck of cards. I am not sure, never having done this kind of roof myself, but I don't think there's any crimping or interlocking or soldering involved. It looks like they are simply nailed on much the same way we nail asphalt shingles on today.
This style dates at least from the early 1900s, possibly earlier. What can you tell me about it?
Dinosaur
'Y-a-tu de la justice dans ce maudit monde?
I'm not familiar with the style of roof you're talking about. 2'x2' sounds pretty big to me. I'm making some copper diamond shaped shingles as we speak. They do not interlock since they get progressevly smaller as the diameter of the roof reduces. The rectangular metal shingles I've dealt with lock on the side only - not on the top.
Here's the cu shingles: http://forums.taunton.com/tp-breaktime/messages?msg=47272.1
Edited 9/17/2004 5:59 am ET by greencu
Nice looking stuff in that link, bro. The calculations for the progression toward the peak must be interesting, too....
The shingles I'm talking about are bigger than that. I'll toss my camera in the truck and see if I can't snap a few pix of a typical example sometime in the next few days.
Dinosaur
'Y-a-tu de la justice dans ce maudit monde?
You won't find the exact answer looking it up in a book. A gamrbel and mansard are technically the same, but in practical usage of the terminology and application to house style as well as historical background, they are different.
I could go into a dissertation of the differences if you like, but it is not important for the point of the Q you ask. The reason I sought clarification is that in mansards, it is more common to have a flat upper portion and to have a sweeping curve in the lower section which is quite a bit steeper generally than in a gambrel. What was on my mind is tha the concave sweep curving inwards would not require an answer to the question you asked because the shingles would not project out, they would need to be forced to lay in. I'll take your word that you have a hip roof keeping rain out on four sides instead of a gable roof covering two sides only. The varieties of slopes can be infinite, considering all the ways actual styles can be bastardized
For examples, I will post some photos instead.
Muddy rudder is a gambrel because it has only two sides in gable end form. If you saw the same shape in a hip roof surronding the building, it would be a mansard, especially if it had other features of a mansard house with detailing from the Empire period and if it had a geographical or cultural French heritage. normally a mansard would have a steeper lower roof section than this shows, and the uypper can be even less steep than this - common at 2/12 to 4/12 but flat upper is not uncommon.
another picture shows a simple Gambrel classic shape with folk dutch colonial details and built shingle style. See how it has a steeper upper roof and a longer lower section.
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I also associate mansrads with the Italianette style. Many Italianettes have only the low slope upper with the same sort of dormers you find for embellishments in the steep slope portion of these mansards placed in a wall instead of steep roof.
http://www.midtel.net/~mcselem/architecture/second_empire_mansard_roof.htm
http://ah.bfn.org/a/DCTNRY/m/mansard.html
http://architecture.about.com/library/weekly/aa100900b.htm
http://architecture.about.com/library/blgloss-mansard.htm
part of my memory is telling me that one diff between gambrel and mansard lies in the historical background. In some places, property taxes were asses by externally measured things that the tax man could see without gaining access to the interior of the hosue which would have been more hazardous duty for him. So taxes were levied on things like number of stories, number of windows ( remeber how expensive glass was back then) and number of chimneys ( which were indicative of number of rooms when each had a fireplace for heat.
So the gambrel is a simplified form of the mansard that would be subject to less property tax, having one less floor levels apparant, and far fewer windows.
Hah! and we thought that dodging the IRS was an American pasttime!
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Hey Piffin . I heard something really close on the Mansard roof thing so I thought I would pass it by you and see what you think.
The whole second story thing reminded me that they assessed the value based on the height and the legal high was determined by the distance from the ground to the soffit line -hense the second story hidden inside the roof and the soffit driven down towards the ground.
Excellent definition about the diff. roof styles . thanks Mike
I'll appologize in advance for going off topic slightly but I really liked the gambrel roof pic you posted. My houses front elevation is almost identical except that at some point in the history of the house the little reverse gable roof over the front stoop was removed. The "boss" really wants a full sized "sittin" porch put on the front so I would be interested in yours and others opinions regarding the design of such a porch, mainly in terms of the roof line. My thoughts are simple shed roof coming off just under the second story shed dormer and extending all the way to the existing roof edge so that you have a continuous edge running all the way down from the gable ends of the main roof. I've seen some where the porch roof is set back in from that line. Framing this would seem to be easier as you wouldnt need to get new and old to match up but I like the idea of the continuous line. Lastly I thought perhaps putting in a reverse gable at the center of the new porch shed, perhaps with a barrel ceiling in order to pay homage to the original design. One question I would have with this approach is how wide to make the gabled portion. Obviously the framing with this approach would be more complicated. The total width involved here from outside wall to outside wall at the front of the house is about 40 ft with approx. 10'" soffits extending out beyond that. I'd appreciate anyones thoughts on the various esthetics raised here. Thanks
i'm a little tired mentsally right now to concieve of this from verbal description.
Any way to post a photo or scanned scetch?
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to follow on with piffens examples... here's some more... from gambrel land...
Mike Smith Rhode Island : Design / Build / Repair / Restore
Here is the 'modern mansard' as googled and the addition I'm putting on my house. The first has a flat roof, the second a peaked roof. The connection is made by having the peaked roof overhang the mansard with soffit and fascia.
Funny discussion on origin of this roof. You are right, it originated in France.
A tidbit: Under the then French tax code, taxes were higher on two-storey homes then one-storey. So the French simply extended the roof down over the second level, turning the building back into a single storey for tax purposes. The power of economics at work!
You're correct: The Mansard roof does indeed come from France. It was designed by and named after François Mansart (later spelled 'Mansard'), a French architect who lived from 1598-1666. Among other major works, he designed L'eglise de Val-de-Grâce in Paris; this design is said to have influenced Wren's design of St. Paul's Cathedral in London. (I wouldn't know myself; I didn't GC that job, LOL....)
François Mansart had a grandnephew who studied with him, Jules Hardouin Mansart (c.1646-1708). Jules designed several well-known buildings, including the Grand Trianon at Versailles, the Place Vendôme in Paris, and the Dôme des Invalides. I've got some neat photos I took of the Place des Invalides showing the Dôme under a black, noontime, thunder-clouded sky, but they're in slide format and I don't have a scanner for slides, unfortunately....
The gambrel roof, which is basically a two-planed Mansard, owes its name to the word for 'leg' in Old French: gambe (in modern French the word is jambe). Thus, a gambrel roof is a 'roof with legs' or a 'legged roof'; very descriptive when you think about it.
In North America, the gambrel roof is often mistakenly labeled a Mansard. (Just like Aunt Jemima syrup is often mistakenly called maple syrup, dammit....)
I've never heard the story about the tax differential for one- versus two-storey houses in France; the only authenticated case of this sort of thing I know about is the New England Saltbox, which was designed the way it was for exactly the reasons you stated. Here in Québec, however, there is an insurance premium differential for what is called a 1½-storey house (second floor rooms in the roof space) versus a true 2-storey house. There are not many 2-storey houses in my area, although I would credit architectural heritage more than insurance savings with that....
Dinosaur
'Y-a-tu de la justice dans ce maudit monde?