Hi! I’m planning to install crown molding throughout the house, starting with the bedroom. I’ve been online looking at different websites and think I get the general idea. My question for all Dopers is… do you have any tips on what I should not do? If you’ve ever installed crown molding, what did you do/not do to make the project go well?
Besides hire someone, I mean. 
My dad and me did this at my parents house a few years ago. I found it easier to finish all the corner pieces first, and then go on from there.
Also I would add the old carpenters saying “Measure twice (Or three times) cut once” 
Make sure you readjust and realign the chop saw that you are going to be using, assuming it’s not brand new. Crown moulding will show any errors in the angle or how level it runs alot more than other kinds of trim.
Also, make sure you have a nice new blade to work with. Nothing worse than fuzzing the edges of all your cuts.
Starting on the corners is helpful also, however I always start on inside corners as they show imprefections in cuts much more, and are more likely to affect how level your trim runs.
Use pieces of scrap to practice your corner cuts. If they both match perfectly then move to the real stuff.
Air nailer. Greatest invention known to man. I have genuine lath and plaster walls. I wanted a chair rail in my office. I bought an 18 ga. air nailer. 3" nails nails and it was cake to put he rail up. Accept no substitute.
Tips are probably better asked for in IMHO. Moved.
samclem GQ moderator
Learn how to ‘cope’ moldings. Google ‘coping crown molding’.
Have help.
Have your saw set with a jig to keep each piece sitting on the saw the same way when cutting. Compound angles will go crazy if each piece sits slightly off when you cut them.
Up and down…up and down: The only way for great fit is to get close to the cut point, then nibble away by making thin slices, going back up the ladder to test fit until it’s perfect. Especially true on outside and overlap cuts.
When having to use multiple sections for long runs you cut the seams at a 45 degree angle. Cut these seams so they angle away from an observer who is standing in the doorway to the room. It hides the seams better.
An even better way to hide seams and gaps is to get some carpenters wood filler and fill in the gaps and seams before painting.
I was coming to say just that. Cope the joints and 45 miter the seams. Typically you would run the piece on the main viewing wall ( the one you look at when you walk into the room) corner to corner and cope the returns left and right to it.
You Tube is a great resource for this. I usually miter one and cope the other, but there are several methods posted on YouTube that you could choose from. Good Luck!
My advice – check your ceilings and corners to make sure they’re reasonably level and square. If so, have at it. If not, dial a pro and let them deal with the headaches.
I cut scrap pieces that matched the corners. Then I labeled the scrap pieces so I knew which one went on which side of the corner, and made sure top and bottom were identified. Crown molding needs to be cut in an upside down type configuration in your miter saw, and it’s very, very easy to flip it to the wrong angle when you cut. Having templates to match makes it a lot more fool-proof. (But not entirely. :smack: )
I’m here to second this advice.
Hand nailing crown molding tends to change the angle at which it’s adhered to the ceiling/wall. Once that happens, you’ll never get your next corner piece to match up. An air nailer allows the nail to be placed so quickly the crown molding won’t moved by the repeated pounding a hammer causes.
Three other things to help amateur crown molding installers is:
use cheat cleats (a little piece triangular wood to ensure that molding stays at the correct angle against the ceiling/wall. There’s probably an official name for them, but I don’t know what it is.
little gaps are pretty much unavoidable (against the wall, and on adjoining pieces). Paintable caulk is your friend. Assuming the gap is not to big, run a bead along the edge, and smooth it out. After its painted you won’t even notice it.
If you’re having a real problem with corners, it’s seems to be a real popular option now to purchase pre-cut corner pieces. Example 1 and Example 2
Don’t Cope! Don’t do it! Don’t do it!!!
Yes, I know that’s how the pro’s do it, but you’re not a pro. Crown molding is difficult enough with the cuts being upside down and no angles being truly 90 degrees, but then when you add the task of coping, the project will go to hell on you in short order.
I’ve installed crown molding by coping before and I’ve read plenty of instructions on how to do it and watched plenty of videos to boot. One thing that they all leave out is the importance of the angle that you cope. In a perfect world where everything is 90 degrees and flat, you should be able to make your coping cut straight down or 90 degrees to the face. However in the real world the angle should be slightly greater (or less depending on your perspective) than 90 degrees so that you end up with a very slight point on the coped piece. This helps to hide any imperfections in the cope or in the molding itself.
On something simple like a chair rail or base board, this is easy enough to do, but on crown molding getting that angle right is a nightmare. First of all, determining what is “straight down” is tricky enough because the molding is going to be at 45, 36, or 30 degrees to the wall. Then add to that all the curves and angles in a typical crown mold and you’re looking at a lot of mistakes on some pretty expensive stuff.
Man, I’m telling you. Just make miter cuts, caulk the gaps, and call it a day.
