one single crown molding installation issues

Is this really what you want?

[This is part of my How to Install Crown Molding Series.]

Most questions and comments I’m asked can be traced to the problems and frustrations people face when installing single-piece crown moldings.

And I totally feel your frustration.  Remember, I was the guy installing his fist single-piece crown molding with a plastic miter box, hammer and a lot of colorful language, too.  It’s only now — from the lofty perch of having done this sort of thing for myself and others since 1992 — that I present this perspective:

  1. The majority of popular tips for installing crown molding are for “quick and easy” projects, but are not necessarily the kind of tips that will result in a rock-solid installation with the best possible finish.
  2. We’ve had nearly one-hundred years of “quick and easy” molding installations, and most of us are not satisfied with the results.  We want something better, and that desire has led you to this page.

Before you read further, remember that you’re reading a blog written by a guy who considers moldings to be the most important part of decorating a home.

Never say Never.  Except For This One Thing

If you’ve read even a couple of my blog posts you’re probably not surprised that I have lots of self-imposed rules when it comes to designing, installing and painting moldings — especially crown moldings.

Problem is, I’ve been following some of my little rules for so long that I’ve forgotten why I’ve become so rigid on a particular point.  I’ve forgotten that moment long ago when I said to myself, “Well, I”m never doing that again.”

One of those things I’m never doing again is install a one-piece crown molding.  Here’s why.

Crown Molding Joint Separation

I was a brand new independent finish carpenter and had just installed what the customer wanted, a one-piece crown molding in her early 70s ranch home.

For structural and aesthetic reasons only, not because of the higher price, I had suggested a three-piece crown for her living room.  I told her that the temperature and humidity changes causes a house to expand and contract, and that will mean the joints in the crown would eventually open up and need to be re-caulked.

This will be ongoing, I said, annual molding maintenance.  But she wanted the small crown, and so got what she wanted.

Crown Molding Nailers

I installed her crown by the book: a beveled 2×4 nailer behind the crown glued and nailed to the studs; bottom of crown nailed to the studs and, my own addition, glue all molding contact surfaces and joints with Liquid Nails molding adhesive.

My Moment of Zen

The call came quicker than I thought.  Within a month she was beside herself, because, as you may have guessed, changing temperatures caused faint separation at some of the joints in her crown.

I returned to the home, caulked and repainted the joints, and all the while I was telling myself, “I’m never going to install another one-piece crown again.”

So that was the last single-piece crown molding I was going to install without a signed waiver acknowledging the joint separation issue.  And during a good economy, rather than deal with the issue at all, I simply stopped installing single-piece crowns, three-pieces became my starter crown.

And you know what?  None of the joints in all of the three-piece crowns I’ve installed since have ever came apart.

My Defense of Three-Piece Crowns


Let’s be honest here, properly designed three-piece crowns are just nicer to look at.  They are powerful.  Complete.  It’s not that a single-piece of crown is inherently wrong in any way.  Single-piece ogee crowns are common in the practical, frontier simplicity of Colonial/Georgian style American homes.

But my own taste in historic homes comes from the grandure of post-Colonial architecture.  I love the elaborate townhouses of Boston, Manhattan, Chicago, London and Paris; I love the Victorian mansions of rural North America, and especially the south’s Greek Revival mansions.

For simple interiors, I much prefer Craftsman style moldings over Colonial.


It takes almost as much work and costs almost as much money to properly install a one-piece crown molding as it does to properly install a three-piece crown molding.  (See Kitchen Crown Molding: Materials from Lowes)

For instance, the 8′ 2 x 4 you’ll need for nailers are not cheap any more, they cost nearly as much as an 8′ long pre-primed mdf baseboard molding that can be used for your lower crown detail.

The lower detail need only be glued and nailed to the wall.  Whereas the 2 x 4 you’ll have to rummage through the stack at the lumber yard to find some that are reasonably straight, then you’ll have to rip them on your table saw so they have the right spring angle bevel, then you’ll have to install them with screws and heavy-duty construction adhesive, and only then can you layer the single crown molding on top.

Then you hope and pray the joints don’t open up when the seasons change.

With all that work, cost and joint uncertainty, why not just go with a nice three-piece crown?

Anatomy of a Three-Piece Crown

stacked crown molding in kitchen

  1. Lower detail is glued and nailed to the room studs
  2. Cornice is glued and nailed to the ceiling
  3. Crown molding detail has an even, rigid surface between ceiling and wall to be glued and nailed to

I think the force of an expanding and contracting house is distributed more evenly through all three pieces of moldings, rather than being expressed at just a few weak spots that can cause your crown to separate.

I’ve installed a lot of three-piece and larger crown moldings over the years, and they have not separated at the joints, even under the stress of large, tall expanding and contracting great rooms.

How to Install a Three-Piece Crown Molding

We recently installed a nice, traditional style crown molding buildup in our kitchen, so if you want to review some very detailed step by step instructions on how to install a three-piece crown, there’s no more complete set of instructions on the web.

Our Kitchen Molding Makeover

Homework Assignment

Between now and the time you make your final decision, take special notice of the crown moldings you encounter in model homes, older homes for sale, B&Bs, hotels, grocery stores, banks — you’ll see them everywhere — and ask yourself:

  • Is the crown large and detailed enough to make a real contribution to the room?
  • Are the inside corner joints separating?
  • Are the outside corner joints separating?
  • Can you see where two pieces of crown were spliced together in the middle?
  • Does it look like the joints have been caulked and re-caulked for years on end?
  • Is the crown molding bowing away from the wall?
  • What’s the finish like?
  • Can you see unfilled nail holes through the paint?
  • Are there heavy beads of caulk where the crown meets the ceiling and wall?

The Most Important Thing: It’s All About You

What I really want is for you to be supper-happy with whatever crown you install, large or small.

Installing a single-piece crown the right way is a lot of work, and installing a three-piece crown is a little more.  And in my experience people are happier with their home when they install a larger crown.

Not once has someone said they wish they’d gone with the smaller crown.  In fact, only the opposite is true.

[This is part of my How to Install Crown Molding Series.]