Exterior Crown Molding

[Ron Kurzius]

I'm working on a job where I'm installing 5" pvc crown molding and having problems making the miters. On the back side of the house the level comes to the corner and goes up the rake at a 4.75 pitch, hits at the ridge and goes down at an 8 pitch then return to level.

I've heard that you are suppose to use two sizes of crown but I only have one size. Has anyone done this with some success?

Thanks.

[keith micinski]

Not having done that exact thing before I am not sure but as you know two different angles changes the length of the end dramatically. I would try and find someway to make a plinth block or some sort of decorative termination so you don't have to combine the two different angles.

[Colin Helms]

Go to garymkatz.com for this information, he has an article on how to install crown on different angles. Good luck with your install.

Colin Helms

[Ron Kurzius]

I have 1X6 fascia and rake and then a 1X8 on the same plain as the roof deck. So the crown is right under the roof. The powers to be said make it work.

[Jason Roehl]

With crown, you'll have to make a wedge-shaped piece between the level run and the rake run. In other words, you would miter the level run around the corner, then make a short piece with the matching miter for the corner. Then, on that short piece's other end, you miter to go up the rake, and miter the rake piece to match. Your wedge piece should end up with a point at the top and a few inches of length at the bottom.

There is no possible miter angle to both go around a corner (inside or outside) and go up a rake (or a cathedral ceiling if working inside).

[scott vroom]

Like Jason said, the secret to turning crown up or down a rake is a small triangular piece at the transition. The cuts are tricky and best described by crown guru Wayne Drake in his illustraded book: http://www.amazon.com/Crown-Molding-Trim-Install-Like/dp/1581125941/ref=sr_1_1?s=books&ie=UTF8&qid=1351257903&sr=1-1&keywords=crown+molding

You don't need 2 sizes of crown to make this transition....it's all done with one size.

Below are a few pics of our work showing the transition.

[Mel Fulks]

A real classical pediment has to have a wider "rake mould" to mitre properly with the level crown. Extremely rare in modern houses since what I call "the stacked dog houses" style came in. Roof crown is a different deal, sounds like they just want something nailed up. I find most of the modern treatments odd looking ,but as long as its not a situation that contributes to causing a leak you will not get any complaints.

[Peter Quinn]

To do this right you need a different crown for each specific rake angle, and the spring angle will have to be adjusted too. But if you have a different rake on each side of the ridge, and these die into a horizontal crown, your molding package is impossible, may have been drawn by Escher.

IME your best bet is to play with the spring angles, make the rake crown flatter and make the horizontal crown stick out more, heat the PVC on once you get it close so they form to each other or spooge them together with 'bond and fill' and sculpt to fit. But there is no set of angles you will hit that let's the same crown go up a rake, and with two different rakes meeting, you are really screwed, so you need to add a little "English" so to speak.

Joe Fusco used to have all the trig equations to figure out the correct spring angles and give you the correct bevel/ miter angles for a given rake angle assuming you had the proper rake crown. But he died and I think his site is shut.

If you have more control over the situation, I'd return the soffit crown into gable end on a frieze board then add a little roof or flashing over a plywood top, then die the rake crown into that so they don't meet, end of problem. You won't have much luck getting a custom PVC crown made easily. Good luck, like to hear how you solve it. Skip the mitered transition block, that looks terrible.

[scott vroom]

Peter, do you have pics of the solution you're describing?



IME your best bet is to play with the spring angles, make the rake crown flatter and make the horizontal crown stick out more, heat the PVC on once you get it close so they form to each other or spooge them together with 'bond and fill' and sculpt to fit. But there is no set of angles you will hit that let's the same crown go up a rake, and with two different rakes meeting, you are really screwed, so you need to add a little "English" so to speak.

[Mel Fulks]

You see those little roofs all over. I don't like them but it seems to be the most popular and realistic fix. You probably have one right down the street.

[Ron Kurzius]

Well, little roof isn't a choice. I have the level to 4.75 and the 4.75 to 8 done. Not my finest work but it looks great from the ground. Trim screws along with with bond and fill are making this happen but it is so wrong on many levels. What is it going to look like six months, a year, 10 years from now.

Sometimes I hate my job.

[scott vroom]

Post some pics!




Well, little roof isn't a choice. I have the level to 4.75 and the 4.75 to 8 done. Not my finest work but it looks great from the ground. Trim screws along with with bond and fill are making this happen but it is so wrong on many levels. What is it going to look like six months, a year, 10 years from now.

Sometimes I hate my job.

[Mel Fulks]

The worst part is that when it fails you will be blamed. The fact that you take your work seriously will count for nothing. Sorry.