How to Sew a Lapped Zipper for the Jenny Overalls

Over the next few posts, we'll be covering some of the trickier construction steps in our Jenny Overalls & Trousers, in addition to a few fun pattern hacks (including free new pattern pieces!) Today, we want to show you show our method for installing a lapped zipper. This method is used to insert a sturdy zipper along a side seam with a pocket, but you can use the same method for any lapped zipper application.

In this tutorial, we will demonstrate how to install the zipper on the right side. I know that women's pants traditionally open on the left, but this is an archaic tradition (leftover from when women were dressed by servants) and a right side zipper is actually much easier to do up if you are right-handed, which the majority of us are (sorry lefties). If you prefer a left side closure, or if are installing a zipper on both sides of your Jenny Overalls or Trousers, mirror these instructions for the left side.

The front pockets need to be constructed before installing the lapped zipper (if you are not adding front pockets you can skip ahead). The front pocket construction for the Jenny Overalls pattern is very similar to our slanted pockets tutorial for the Sasha Trousers pattern. The top pocket facing (H) should be interfaced. Finish the long curved edge of the top pocket facing and bottom pocket facing (G) with either a serged or zig-zag stitch. Position the facings on the top and bottom pocket lining pieces (E and F) with wrong sides together, and stitch around each facing 1/4" from the edge.

With wrong sides together, match the top and bottom pocket linings along the curved seam. Sew together at 5/8" seam allowance, and finish the raw edge with a serged stitch. If you do not have a serger, trim the seam allowance down to 3/8" and finish the raw edge with either a zig zag stitch or by using pinking shears. You could also finish this using a french seam.

Open the pocket bag and with right sides together, match the top pocket facing to the curved pocket opening on the front leg. Stitch together with a 5/8" seam allowance.

Turn the pocket bag to the wrong side of the front leg and press along the curved seam.

To finish the edge of the pocket opening, you can either understitch the top pocket facing to the seam allowance, or you can topstitch along the pocket opening. For this sample we topstitched 1/8" from the pocket edge using white topstitching thread. Align the top and bottom pocket linings with the waist and side seams, matching notches, and baste in place.

For our sample we also wanted to add some additional topstitching detail to the front pockets by sewing along the curved edge of the pocket bag. To prevent the pocket bag from shifting and to provide a stitching guideline, we basted the pocket bag in place using a contrasting thread.

From the right side of the front leg, we shifted our needle and sewed a first line of topstitching along the inside of our basted guideline.

Then we sewed a second line of topstitching 1/4" inside the first line.

Gently remove the contrasting basting thread and give your front leg a final press. We are ready to install the lapped zipper!

It is very important to note that the side seam allowances for our Jenny Overalls pattern are one inch! As one of our wonderful testers pointed out during development, a larger seam allowance can be really helpful when installing a lapped zipper, since you'll have a little more room to play with when you are flipping your zipper over the seam line, especially if you are using a zipper with wider tape or teeth. The side seam where the lapped zipper will be installed will ultimately be pressed open. You may choose to finish your raw edges now with a serged or zig zag stitch, or you may choose to finish them after installation so you can trim them down. We sewed this sample for our model and knew we might have to make some fitting adjustments, so we serged these edges before installing the zipper.

Pin the front and back right legs together along the side seam, matching notches. With the right front leg facing wrong side up, determine the position of your zipper. The top of the zipper teeth will start just below the 5/8" waistband seam allowance. We recommend a 7" zipper for the Jenny Overalls pattern. With a removable marking tool, mark the position of the top zipper teeth and bottom zipper stop.

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Starting at the waist of the leg, sew the side seam at the 1" seam allowance using a long basting stitch. It can be helpful to backstitch a few stitches when you start sewing so the basting stitches don't come undone when you press this seam open at the next step. When you reach the marking you made to indicate the placement for the bottom zipper stop, switch to a regular length stitch and continue sewing. Backstitch to the marking a few times to secure, and finish sewing the right side seam all the way to the hem.

Press the side seam open and ensure the zipper placement markings you made are still visible. A tailor's ham will help press the curve of the hip seam.

With the back leg folded out of the way, position the zipper face down over the side seam between the top teeth and bottom stop markings. Pin the zipper to the seam allowance of the back leg only.

The edge of the zipper teeth should be aligned precisely to the right of the seam.

Using a zipper foot, sew the zipper to the back leg seam allowance only, keeping the right leg out of the way. Stitch as close as you can to the zipper teeth. Sometimes it can be hard to sew a straight line because the zipper pull gets in the way. If this is difficult, try starting the stitch line with the pull down. When you reach the pull, keep your needle down, raise the presser foot, and carefully pull the zipper stop back up.

Fold the seam allowance and zipper under along this stitch line and press.

Sew a line of topstitching to the left of the zipper along this fold to secure.

Flip the zipper over the side seam so that the other side of the zipper tape is resting flat along the right front leg seam allowance. Pin in place.

Sew the zipper to the right front leg seam allowance only. Stitch close to the teeth and keep the right leg out of the way.

It's time to topstitch the zipper in place from the right side of the pants. Determine the bottom zipper stop placement by pushing a pin from the wrong side into the pocket bag.

Draw a topstitching guideline with a removable marking tool. Depending on the width of your zipper, this line may be 3/8"-1/2" away from the side seam on the right front leg. Use your fingers or a few pins to make sure the line is not overlapping with the zipper teeth. We used a jeans zipper instead of a traditional pants zipper for this denim sample, so we found a 1/2" distance worked best. Your guideline will extend into the inside of the pocket since the zipper extends past the pocket opening. The guideline will end just below the bottom zipper stop.

Sew along the marked guideline starting from the waist. Go slowly and make sure the layers of fabric are resting nice and flat, and that you are sewing to the right of the zipper teeth.

When you reach the inside of the pocket bag, carefully open the pocket and continue sewing. It may help to undo the basting stitches keeping the pocket lining in place along the waist of the leg.

When you reach the bottom zipper stop, keep your needle down and carefully turn the corner. Sew to the side seam and backstitch. If you are unable to turn the corner, backstitch at the end of your straight line of stitching.

Sew a sturdy bar tack through the pocket opening and pocket bag. The bar tack should continue along the topstitching line you just stitched, and will help secure the pocket opening. You may remove the basting stitches from the side seam now and test out your zipper!

Prepare the fly shield for installation. Fold the fly shield (I) in half with right sides together and sew one short edge closed at 5/8". Trim the seam allowance, clip the corner, and press right side out.

If you have already finished the raw edge of your right leg seam allowances, finish the seam allowance of the long raw edge of the fly shield.

Pin the fly shield to the back leg seam allowance only so that the top of the fly shield matched the waist of the pants, and the zipper is concealed. Sew the fly shield in place. If you haven't finished your seam allowances, you may trim them down now and finish them separately with either a serged or zig zag stitch.

Et voila! A sturdy hidden zipper for all your pants wearing needs!

We'll be back later this week with our tutorial on sewing a tabbed waistband, and then next week we'll show you how to replace the zippers entirely with a pretty button closure!