Socks: What’s All the Flap About?
It’s a topic of passionate debate among sock knitters: short-row or flap-and-gusset heels?
Today I’m focusing on flap-and-gusset heels.
Sock Heel History
The flap-and-gusset heel construction is traditional; it’s how most hand-knit socks have been made. But it’s rather fallen out of favor, for a few reasons. The first is that some find it a bit trickier to work—fair enough, although trickiness is often a question of familiarity. The second is that a short-row heel is very easily adapted to toe-up socks—you can work it in either direction. As toe-up construction got more popular, so did the short-row heel.
But the third reason is the most interesting. We love a sock with a short-row heel because it looks like the socks we buy in the stores. But here’s the funny bit: store-bought socks look like that because it was all the original sock knitting machines were capable of making. But as I mentioned in my previous piece, the short-row heel isn’t always the best fit.
Flap-and-Gusset Construction Explained
The big benefit to flap-and-gusset construction is that it results in a sock that is expanded in the heel area, and in the foot in front of the heel, which matches the shape of many adult feet.
The three crucial fit points of a sock.
A foot, happily ensconced in a flap-and-gusset Heel sock.
A flap-and-gusset heel is constructed in three steps.
Step 1: The Flap
Once the leg is complete, you first work a length of fabric back-and-forth in rows, on half the sock stitches. This fabric will sit on the back of your heel. It’s typically worked so that you’ve got about the same number of rows as you have stitches.
RS rows: Slip 1 purlwise (pwise) with yarn in back (wyib), k to end.
WS rows: Slip 1 pwise with yarn in front (wyif), p to end.
End with a WS row.
Here, the flap has been worked, and markers have been placed for the next step.
(For reinforcement, the heel flap can be worked in a slip-stitch pattern. More on this in a future column.)
Step 2: The Turn
The heel turn is worked on the flap stitches, and sits under the foot.
There are a few heels turns that work well in this construction.
Half Handkerchief, so-called because it looks like the triangle of a folded handkerchief.
Round. No prizes for guessing for why it’s called that.
The square heel is my favorite, because it’s easy to work on any number of stitches, and has a nice tidy fit. This is the one I’m going to give you the instructions for.
Another view of the square heel on the bottom of the foot.
For each type of heel, the turn is shaped using decreases. Not a single short row wrap and turn is required! For some knitters, this is reason enough to change methods.
Working the Turn
To start, divide the heel stitches as evenly as possible into thirds. Does the number of stitches divide evenly by 3? If so, then you’ve got equal thirds. If the number of stitches doesn’t divide evenly by 3, you’ll have two thirds that are the same, and one that doesn’t match, that’s either one more or one less. For example, 27 is 9/9/9, 28 is 9/10/9, 29 is 10/9/10, and so forth.
Place stitch markers to divide the heel flap stitches into thirds. If you’ve got a non-matching number, that’s the middle set.
There are those markers again.
Heel turn row 1 (RS): Slip 1 pwise wyib, k to 2nd marker, slip marker, ssk, turn.
After the decrease, there will be stitches leftover at the end of the row. Ignore them for now. Turn really means turn! You’ll come and back later and decrease them away.
Heel turn row 2 (WS): Slip 1 pwise wyif, p to 1st marker, slip marker, p2tog, turn.
There will be stitches leftover on both sides, with a bit of a gap separating the leftover stitches from those in the middle.
The first two rows of the turn are complete. You can see the decreases, just outside the markers, and the gaps just past the decreases.
In each of the following rows, you’ll decrease away one of the leftover stitches. The decrease is always worked in the same place, just outside the marker, so it’s easy to keep track of where you are.
Heel turn row 3 (RS): Slip 1 pwise wyib, k to 2nd marker, slip marker, ssk, turn.
Heel turn row 4 (WS): Slip 1 pwise wyif, p to 1st marker, slip marker, p2tog, turn.
Repeat rows 3 and 4 until you’ve worked all the stitches, and only 1 stitch remains either side of the marker. A helpful tip: after a WS decrease is worked, you should have the same number of stitches after the gap on both sides.
Done! That wasn’t hard, was it?
Step 3: Reunite the Round
Once the heel is turned, you have two sock parts: the heel on one side and the instep on the other, with two giant gaps either side.
To close these gaps and resume working in the round, you pick up stitches on each side, between the heel turn and the instep. This construction, by design, results in more stitches—and thus more fabric—to fit comfortably around this usually larger part of the foot.
stitches picked up for the gusset.
You then work decreases to narrow the sock as you head towards the toe, matching the shape of your foot. (This is why it’s called a gusset. Gusset is a tailoring term for a triangular insert of fabric. The triangle in the sock is created with the decreases.)
Creating the Gusset
Foot setup round:
Knit across the heel stitches, pick up and knit stitches along the first edge of the heel flap, using the slipped stitches as a guide.
How many stitches? Usually, it’s one for every slipped stitch. I like to pick up one or two extra to help avoid a hole.
There’s a trick to this: don’t pick up in the “corner,” but rather continue in the straight line, up a little bit into the leg of the sock. Much tidier: no hole!
Then work across the instep stitches in pattern as set. (Your pattern may be plain stockinette, as shown in the photos.)
Pick up and knit stitches along the second edge of the heel flap, trying your best to get the same number you got on the first side. (If it’s one off, you’ll be fine—I won’t tell anyone.) Then knit until you’re at the midpoint of the heel stitches. This is the new start of round.
Here’s a refresher on how to pick up stitches.
You will have more stitches than you started with. That’s by design, to create that extra space in front of the heel.
At this point, it’s helpful to arrange your needles so that the instep stitches are grouped together on one needle. If you’re on magic loop or two circulars or flexible DPNs, the sole stitches should be on one needle, and place a marker in the middle to designate the start of the round. If you’re on traditional DPNs, the start of the round is at the start of the first needle; put the instep stitches on a second, and the rest of the round on a third. This way you can easily keep track of where you are.
Work a round to settle and tidy up the picked-up stitches:
K to the end of the heel stitches, work ktbl (knit through the back of the loop) on all the picked up stitches up to the instep; work across the instep normally; work ktbl on all the picked up stitches (down to the heel) and k to end of round.
Gusset decrease round 1: K to 3 sts before instep, k2tog, k1; work across instep in pattern as set; k1, ssk, k to end of round.
Gusset decrease round 2: K to instep; work across instep in pattern as set; k to end of round.
Repeat the last 2 rounds until you’re back to your original stitch count. Then complete the sock as written.
Plug and Play!
You can use this heel construction on any top-down sock pattern without requiring any further pattern changes. Try it!