Three PC crown

[Neilthecarpenter]

I am getting ready to start a large three PC crown job. The crown is poplar so there will be no play. Needs to be perfect. I'm concerned about reveals etc. how would you do this to be as efficient as possible?  By the way I am a very experienced high end trim guy just looking to learn some ideas from you guys. Thx

 

[tjbnwi]

How flat are the ceilings? I'd check it with a laser.

Lower detail, crown, cornice?

Tom

 

[WarnerConstCo.]

I am curious about the no play because its poplar, part. 

 

[Integrity_Construction]

No play in regards to what ?

 

[justinh]

As Tommy said I check for flatness usually with a string.  If it is out badly it will need to be floated either before or after install.

To position all of the parts on the wall as I run them I use a little jig like the one pictured.  The one shown is for a single but it was the only one I could find.  For a build up I cut notches at all the heights and projections of the multiple parts.  Each layer gets referenced off the jig and usually ends up where it belongs.  I use the jig and 2' mock ups of the build up to mark corners and snap lines to use as a reference. 

I also use as few nails as possible when setting wall and ceiling bands of moulding to allow for adjustments.  As I install the crown I tap bands up and down with a block, pry them forward or down with a glaziers bar and nail them to the crown with short nail to lock them together and then shoot them as a unit to the studs/joists.

Another trick to maintain reveals is to change the spring angle of the crown.  To do this you either rip or plane off the back of the top horizontal flat of the crown.  The vertical face of the crown is left intact but meets the ceiling at a point.  You then measure down from the ceiling to the reveal line you must hit.  Draw a mark on the fences of your miter saw up from the base at that height and set a front stop. When cutting crown in position that mark is the bottom of the crown.  Make a new mark for every change in elevation around the room and move the front stop accordingly.  The crown is "twisted" for lack of a better term between elevation changes.  Most of the crown profiles will twist enough to tighten up regardless of species.  The pictures show the process.  The cabinet cornice was set level in the picture and the ceiling was 5/8" off from one side of the kitchen to the other.  The ceiling had t&g planking so no floating and the crown had to land evenly on the moulding shelf shown.  The crown was small so it was easier to adjust than some I've done but this is the only one I have pics of.  The other picture is of the saw fence marked up for changing heights.  The upside to this is that reveal lines are perfect.  The downside in that the moulding details read at a down slope instead of level or plumb.  Most people would be hard pressed to pick up on it though.

Occasionally I will back cut and scribe the top band of the crown but is rare and last resort kinda stuff.

 

[tiralie]

  The cabinet cornice was set level in the picture and the ceiling was 5/8" off from one side of the kitchen to the other.  The ceiling had t&g planking so no floating and the crown had to land evenly on the moulding shelf shown.

Looks really good.
So did you twist the crown to stand it up taller/shorter to make up the 5/8" difference?
Tim

 

[justinh]

Tim,

The crown was twisted to lower it.  I figured out at what point the crown sat at its designed spring angle and deduct from there.  You can raise it past that but you would have to modify the angle on the portion of the crown that hits the wall instead of or in addition to modifying the angle that it hits the ceiling.  Based on the size of the crown on this one and the desired reveal in the build up it was best to lower it, but splitting the difference can be necessary.

In addition to cabinet crown and built ups this technique is also useful when crown runs above something like a bank of windows and the ceiling is off level but the windows are level (ish).  The eye will be more likely to pick up the height difference between the top of the window casing and the bottom of the crown than a pitch in the flats of the moulding profile. 

I found a picture of the lowest corner of this crown.  You can see the angle in the vertical details on the moulding.  No one noticed it until I pointed it oout.

 

[tiralie]

Thanks Justin.

You can raise it past that but you would have to modify the angle on the portion of the crown that hits the wall instead of or in addition to modifying the angle that it hits the ceiling. 

Yes, I have had to this when matching existing to new crown buildup, but only because I was unable to twist because of the length of the crown and my lack of planning or foresight.

In addition to cabinet crown and built ups this technique is also useful when crown runs above something like a bank of windows and the ceiling is off level but the windows are level (ish).

The eye will be more likely to pick up the height difference between the top of the window casing and the bottom of the crown than a pitch in the flats of the moulding profile.

Agreed. I had to scribe and cut about 1/2" off the top left of the ovolo section of this crown on the cabinet below. I tried to twist it, and modify the angle it hit the bulk head, but it projected too far and I felt it was too noticeable. In retrospect I could have installed the cabinet a 1/2" higher on the opposite end but I really don't like doing that.
[attachimg=1]

I found a picture of the lowest corner of this crown.  You can see the angle in the vertical details on the moulding. 

I can't see it but I trust you.  [tongue]

No one noticed it until I pointed it out.

I am always surprised at what folks (customers etc.) notice or don't notice. It's usually not what I (we) notice.
Tim