How do you lay out a shelf in an opening that is not square?

[Richard Venturelli]

Wondering if anyone has a fast and effective way of measuring and laying out a shelf in an opening that is not square? I have been installing shelf's in niches which have become common in new homes and it seems no one can do square and plumb walls any longer. The only way I have found is to cut a template from cardboard. Wonder if there maybe a scribe way of doing this? But can't see how this could be done because it's all inside measurements between 2 walls. Looking for a faster tip on this problem...

Thanks,
Rich

[Larry Edgerton]

I cut them long and tip them in at an angle, and then scribe. You do the same for the other end but you have to scribe to a point, usually the back corner for me. Mark that measurement on your shelf and set your scribe to it when it is in place.

I tried using a stair tread like jig to mark both ends but it is too unwieldy in a closet, and didn't scribe in the terrible drywall work in closets, so I went back to scribing.

I sub the trim out from some paper contractors, and I run into this all the time. Ticks me off, especially when these kinds of guys beat me on whole house bids.

[Dewey Torres]

Rich,
I ran into this problem when I installed the top for my shoe cubby.

I got lucky that the 2 opposing walls were flared outward instead of inward.

What I did though was cut the top over sized (too deep) then I matched the 2 opposing sides to the off angle until it fit. Now that I was left with the depth to cut, I made a hard board template using a flat washer and a pencil and match it up with my finish depth and made the cut. Came out perfect but there may be a faster way.

[Anthony Whitesell]

For mounting things on pieces that are not true, I use a method stolen from the cabinet installers. When a cabinet is installed, the unit is leveled without regard to the wall. Then a compass is used to scribe the wall shape to the back of the side of the cabinet. If the niche has a square wall that you can hold a piece against, then this may provide a less trial-and-error way of finding the shelf shape.

[Richard Venturelli]

I cut them long and tip them in at an angle, and then scribe. You do the same for the other end but you have to scribe to a point, usually the back corner for me. Mark that measurement on your shelf and set your scribe to it when it is in place.

I tried using a stair tread like jig to mark both ends but it is too unwieldy in a closet, and didn't scribe in the terrible drywall work in closets, so I went back to scribing.

I sub the trim out from some paper contractors, and I run into this all the time. Ticks me off, especially when these kinds of guys beat me on whole house bids.

Let me see if I got this right, Using 36" as an example of the opening, cut the shelf 37" set your scribe at 1/2" place shelf in opening on angle and scribe. Place the other end on angle and scribe that side? Would that work?

[Scott Loven]

Buy this, or make something like it
Scott

[Chris Padilla]

Watching This Old House many, many times, I've seen our buddies Norm and Tom use a compass as a scribe...as outlined by Anthony.

[Joe Scharle]

Take the back angle with a sliding bevel. Measure the front. Take a straight edge to extend the angle from the back to the front. It's easier to do than explain!.

[Larry Edgerton]

Let me see if I got this right, Using 36" as an example of the opening, cut the shelf 37" set your scribe at 1/2" place shelf in opening on angle and scribe. Place the other end on angle and scribe that side? Would that work?

Ya, you got it.

The amount extra you leave is dictated by how out of square that the closet is, but that is something that you will pick up as you go. Usually they are not more than a 1/4" out, but hey, they don't call'em framers for nothing.

The first end cut just set the scribe at the size of the largest gap, on the other end go to the back corner measurement and set the scribe to that point. You don't want to get them too long as then the angle that they are at in the closet gets too sharp, but that too will come after a few tries. Set your scribe a little short on the second cut to compensate for the angled shelf, you can always cut it again.

[Myk Rian]

You could do it like countertop installers. Make a template out of furring strips, and transfer that to the shelf stock.

[Chris Konikowski]

Buy this, or make something like it
Scott

I made something similar to this when I did my staircase. Pretty easy to make and every tread fit perfect. Don't see why it would not do it for a shelf as well...

[harry strasil]

A simple solution to an everyday problem for sheetmetal workers and metal fabrication shops.

It depends on how accurate you can measure.
I usually use a large compass, but 2 shorter pieces of light metal or wood strips that are shorter than the whole distance needed to measure will work.
Just put the ends of the pieces where you want them and clamp them together, they used to make sliding rulers that did this, then measure the length.

1. draw out exactly where you want the shelf to go or use masking tape.

2. accurately measure all 4 sides.

3. accurately measure one diagonal from opposite corners.

4. start out by laying out side A on one edge of the intended shelf piece.

5. using a compass, lay out side C with an arc.

6. lay out diagonal X with an arc and draw in side C.

7. lay out sides B and D with compass arcs and draw a line from the end of A with point where arc B and D cross

8. draw in line D

9. cut on the lines, it will fit every time.

Remember High School, its called Geometry.

Jr.

[Chris Padilla]

What Harry showed will work but it won't be a nice fit if there is a wave in the wall. Harry's method will get you close enough that you can then scribe right onto the shelf (assuming you have enough material).

One other trick is to back-bevel the edges you are trying to fit. Don't try and cut waves into a 3/4" piece of plywood. Bevel that sucker to a 1/4" and it'll be much much easier to shape and cut to fit. I use this trick on base molding when the floor isn't totally flat.

[Larry Edgerton]

I made something similar to this when I did my staircase. Pretty easy to make and every tread fit perfect. Don't see why it would not do it for a shelf as well...

Because stair stringers are straight and true, and closets have the worst drywall work in the house. You have to make up for the taping cove. If you cut a straight line there will usually be a gap in the middle.

[Larry Edgerton]

What Harry showed will work but it won't be a nice fit if there is a wave in the wall. Harry's method will get you close enough that you can then scribe right onto the shelf (assuming you have enough material).

One other trick is to back-bevel the edges you are trying to fit. Don't try and cut waves into a 3/4" piece of plywood. Bevel that sucker to a 1/4" and it'll be much much easier to shape and cut to fit. I use this trick on base molding when the floor isn't totally flat.

Absolutely! I have one router with a chamfer bit in it all the time when I trim so I can take the back out of baseboard, shelves and so forth that have to be scribed. I use a jigsaw to cut shelves in. By gosh, buy Bosch.

Some of the methods stated will work good on your own home, but you have to be faster in the market place, or you are dead meat.