Crown molding for wire tray

[Michael W. Clark]

I'm planning to attach some crown molding (short standard variety) set down from the ceiling to hide some speaker wires and maybe some rope lighting in the future. I was going to bevel rip some 2x4 material to make nailers and hold the crown at the right angle.

After measuring the crown, looks like I need an angle of 36 degrees from vertical and that I should probably use 3/4 material. Not sure if this clear, but does this sound right? I'll probably just resaw the 2x4s, lot of work but easier than going back to exchange it. Anyone else do this and have any opinions?

Thanks
Mike

[Jerry Miner]

Yes, a beveled backer is a common approach to crown installation. The most common "spring angle" (angle between wall and back of crown) is 38 deg. but it's possible that 36 works better for your crown. Go with what works.

[Michael W. Clark]

Thanks Jerry, I will double check the angle then.

[Jason Roehl]

Michael, the nailing backer for a crown molding isn't for holding it at the correct angle--it's simply a nailer. If you try to perfectly match the spring angle with the backer, minor variations in your wall surface will be magnified. Since you're talking about rope lights as a possibility, I'm guessing you're going to hold the top of the crown an inch or several from the ceiling. In that case, I would maybe attach nailer blocks to the wall every other stud or so, but you might find that simply nailing the crown at the bottom into studs will hold it in place sufficiently to hold a few speaker wires and some rope lighting behind it. You just won't be able to do pull-ups from it. ;)

[Richard Coers]

Are you talking about lumber yard 2x4s? You are going to get some really wild boards from that stock. Nothing will be straight, and you're going to spend a fair amount of time just trying to get them flat against the wall. If you have to get lumber yard material, I get 2x8s or 10s and rip from the edges that are not near the pith of the log. At the BORG, it's tough to find 2x4s that stay straight in the rack, let alone ripping little pieces off them.

[Michael W. Clark]

Michael, the nailing backer for a crown molding isn't for holding it at the correct angle--it's simply a nailer. If you try to perfectly match the spring angle with the backer, minor variations in your wall surface will be magnified. Since you're talking about rope lights as a possibility, I'm guessing you're going to hold the top of the crown an inch or several from the ceiling. In that case, I would maybe attach nailer blocks to the wall every other stud or so, but you might find that simply nailing the crown at the bottom into studs will hold it in place sufficiently to hold a few speaker wires and some rope lighting behind it. You just won't be able to do pull-ups from it. ;)

Good point Jason,
I may not need the angle at all. I was thinking the angle would help me register the crown against the nailer. The crown will be several inches below the ceiling. I was going to use a spacer to set the nailer below the ceiling (not worried about level, more concerned about a consistent gap or reveal).

[Michael W. Clark]

Are you talking about lumber yard 2x4s? You are going to get some really wild boards from that stock. Nothing will be straight, and you're going to spend a fair amount of time just trying to get them flat against the wall. If you have to get lumber yard material, I get 2x8s or 10s and rip from the edges that are not near the pith of the log. At the BORG, it's tough to find 2x4s that stay straight in the rack, let alone ripping little pieces off them.

Yes, I've ripped them down before, have to use a splitter (should anyway) and try to pick straight stock, and use hold downs. I originally planned to bevel rip two sides of the 2x4s, then rip that in two. However, I think the 1-1/2" thickness is too much. Probably going to rip them into 3/4" wide strips, then bevel those if needed. I can make the 3/4" wide strips conform to any wall variations, no problem.

Mike

[Jeff Monson]

I use 3/4" plywood, rip the strips to the width of the nailer and cut the angle on a mite saw. Works great and is quick to make up a bunch. I also used pocket screws to screw the nailer up into the header.

[scott vroom]

I also don't understand the need for the nailer. Just shoot nails through the lower half of the crown into the studs, same as you'd do when attaching crown to a cabinet face frame. Adding nailers is an unnecessary step as long as the crown will not be load bearing. Best thing to do is try a sample without the nailer and see if it works for you.

[Michael W. Clark]

I should add this is MDF crown and not hardwood furniture grade. It would be great if I could do it without the nailer. I thought the nailer was standard practice.

[Jason Roehl]

I should add this is MDF crown and not hardwood furniture grade. It would be great if I could do it without the nailer. I thought the nailer was standard practice.

Yikes. I don't know that I would want to hold MDF crown off the ceiling. It's pretty flimsy stuff, and easy to pull off of nails. I would use factory-primed pine or poplar. In the grand scheme of things, it's only a few bucks difference compared to the amount of labor you're going to have into the project.

[Michael W. Clark]

Yikes. I don't know that I would want to hold MDF crown off the ceiling. It's pretty flimsy stuff, and easy to pull off of nails. I would use factory-primed pine or poplar. In the grand scheme of things, it's only a few bucks difference compared to the amount of labor you're going to have into the project.

Nailing through the bottom only, may be good enough but wasn't sure, so I bought the MDF counting on needing the nailer regardless.

I'll do some experimenting this evening to see what I come up with on the nailer. I don't think beveling is going to help me much. This crown has the same profile on both sides (front and back). I haven't seen it that way before, but that means I don't have a flat surface on the back, so only one or two points of contact for the nailer regardless.

Mike

[Michael W. Clark]

I use 3/4" plywood, rip the strips to the width of the nailer and cut the angle on a mite saw. Works great and is quick to make up a bunch. I also used pocket screws to screw the nailer up into the header.

Hi Jeff,
Can you explain your method in a little more detail? I am not sure I am following your suggestion, but sounds interesting.

Mike

[Jeff Monson]

Hi Jeff,
Can you explain your method in a little more detail? I am not sure I am following your suggestion, but sounds interesting.

Mike

I'll try my best.....I put a piece of crown on my bench and with an angle finder you can figure what angle your block will have to be. I make a test block that will fit, you can easily mock up the wall and ceiling on the bench with a couple scraps along with the crown to dial it in quickly. Once I have a test block made, measure the shortest leg of the triangle block. Rip some plywood to this measurement, take the test block and square it up with the end of the strip and transfer the angle with a pencil. I then cut the angle with my mitre saw, cut on the pencil line and note the angle of the saw as you will be swapping from angle to square cut often. After you cut the angle cut, you now have the same angle on the end of your strip, so all you have to do is square the saw and cut it off. This makes 2 pieces fairly quick. I set up my flip stop on the fence so I have a reference on the angle cut. I also stack 2 strips, so that speeds it up more. Once I get enough blocks cut for the job, I like to remove part of the 90 degree corner with a disk sander, no drywall corners are exactly square so clipping the corner makes a really nice fit. I then cut a pocket hole in each block, there may be better ways to attach the blocks, but this works well for me. I screw the nailer blocks up and then put a piece of masking tape on the wall so I know where my blocks are once the crown is up. I will not install crown anymore without using blocks, the crown is rock solid once attached.

[Michael W. Clark]

I'll try my best.....I put a piece of crown on my bench and with an angle finder you can figure what angle your block will have to be. I make a test block that will fit, you can easily mock up the wall and ceiling on the bench with a couple scraps along with the crown to dial it in quickly. Once I have a test block made, measure the shortest leg of the triangle block. Rip some plywood to this measurement, take the test block and square it up with the end of the strip and transfer the angle with a pencil. I then cut the angle with my mitre saw, cut on the pencil line and note the angle of the saw as you will be swapping from angle to square cut often. After you cut the angle cut, you now have the same angle on the end of your strip, so all you have to do is square the saw and cut it off. This makes 2 pieces fairly quick. I set up my flip stop on the fence so I have a reference on the angle cut. I also stack 2 strips, so that speeds it up more. Once I get enough blocks cut for the job, I like to remove part of the 90 degree corner with a disk sander, no drywall corners are exactly square so clipping the corner makes a really nice fit. I then cut a pocket hole in each block, there may be better ways to attach the blocks, but this works well for me. I screw the nailer blocks up and then put a piece of masking tape on the wall so I know where my blocks are once the crown is up. I will not install crown anymore without using blocks, the crown is rock solid once attached.

Thanks! I think I understand. My crown will be set down from the ceiling, but may be able to use this concept. I could face nail from the block into the stud. Basically using a block on each stud instead of a continuous nailer. Rip the bevel and chop it into blocks from the strip.

[Jeff Monson]

I could face nail from the block into the stud. Basically using a block on each stud instead of a continuous nailer. Rip the bevel and chop it into blocks from the strip.

That is basically what I do, mine are not a solid nailer, just blocks chopped from a strip. If you attach them to studs, they would be very solid. I usually install tight to the ceiling, so my blocks just screw into the header, I angle the pocket hole toward the corner.

[Michael W. Clark]

Thought I would post a follow up on what I did.

My crown molding is MDF and molded on both sides, not flat on the back. I guess that is done ot minimize waste and set ups. People that run crown all the time can probably benefit from it. The fact that the back is not flat, made it more difficult for me. I ripped the 2x4s into 3/4" wide rips so that I had strips that were 3/4" x 1-1/2". I then cut the strips into blocks about 4" long. I made a spacer to space the blocks down from the ceiling at the correct height and nailed them into the studs with a 16ga nailer using multiple nails per block.

After the blocking was up, I used another spacer to set the height of the molding as I installed it. This was tricky because of the back not being flat. I would push the molding up until it contacted my spacer, block, and was flat against the wall. I nailed it on with 18 ga brads into the studs and the blocking. It is more rigid than I thought I would be, but not something you would to try to pull on.

If I were to do it again, I would prefer the flat back crown, and solid would probably be preferrable too. A filler strip installed to space the molding away from the wall a little would provide more room in the chase for wiring, but this was ample room for speaker wire. Should be enough room too if I want to add rope lighting later. I had to find a chart to compound cut some of the odd angles (I cut it all laying flat), two were obtuse at 131 and 138 degrees. Without the chart, I would have had to break out the CAD to find the bevel and miter angles for those. I'm definitely not a pro, so unfortunately I'm goind have to let caulk hide some of the sins.

Here are some pictures.

[George Bokros]

Looks good Michael. We did an addition to our last house, an octagon sun room with a cathedral bead board ceiling , and the builder suggested running crown around the room and putting low voltage lighting around behind the crown and it was absolutely beautiful.

George