A sew-in is a hair extension method where wefted hair is stitched onto braided cornrows on your scalp
A sew-in (also called a weave) involves braiding your natural hair into tight, flat rows close to the scalp, then hand-stitching wefted hair extensions onto those braids using a needle and thread. The wefts—the horizontal strips that hold multiple strands together—sit on top of each braid, and you stitch through the weft and around the braid to anchor the extension. When done correctly, the braids support the weight of the extensions and the stitching keeps them from sliding or shifting.
The process takes two to four hours depending on how much hair you're installing and how many braids you need. You'll need supplies you can buy at any beauty supply store, a steady hand, and either a friend to help or the willingness to pay a stylist. The extensions typically last four to eight weeks before they need to be removed and your hair needs a break.
Key Takeaways
- Sew-ins require cornrow braids as a foundation, thread, a curved needle, and wefted hair extensions purchased by the bundle or pack.
- You stitch the weft to each braid individually, working from one end of the head to the other in rows, using a straightforward running stitch or whip stitch.
- Tension matters: braids that are too tight can cause hair loss and scalp pain, while braids that are too loose won't hold the extensions securely.
- After four to eight weeks, extensions must be removed and your natural hair should rest for at least one to two weeks before reinstalling.
- Improper installation or leaving extensions in too long can damage your hairline and cause traction alopecia, a form of hair loss.
What you need to buy before you start
Visit a beauty supply store and purchase wefted hair extensions (sold by the bundle or pack), a curved needle designed for weaving, thread that matches your hair color, and scissors. The curved needle is essential—a straight needle will not work because you need to angle the needle to pass through the weft and around the braid without piercing your scalp.
Hair extensions come in different textures and lengths. Straight, wavy, and curly are the most common. Buy enough bundles to cover your head; most people use three to five bundles depending on hair thickness and how full they want the style to look. The weft should be intact and not fraying or separating from the hair.
You'll also need clips to section your hair, a spray bottle with water, and a comb. Some people use a wig cap under the braids to reduce scalp irritation, though this is optional.
How to braid the foundation rows
Start with clean, dry hair. Section your head into rows using clips, working from the nape of your neck upward. Each row should be about half an inch to three-quarters of an inch wide—wide enough to hold stitches but not so wide that the braid becomes loose.
Braid each section into a tight cornrow, braiding from the roots to the ends. The braid should sit flat against your scalp and feel snug but not painfully tight. If your scalp is burning or you feel sharp pain, the braids are too tight and you risk hair loss. Tight braids should feel firm, not agonizing. find each braid at the end with a small elastic band.
The number of braids depends on your head size and hair thickness, but most people create four to six rows running from front to back. Leave a small section of hair unbraided at the front hairline so you can blend your natural hair with the extensions later.
Stitching the wefts onto the braids
Thread your curved needle and tie a knot at the end. Start at the back of the head with the first braid. Position the weft on top of the braid and push the needle through the weft and around the braid, pulling the thread tight so the weft sits snugly against the braid.
Use a straightforward running stitch or whip stitch, moving along the length of the braid. Make stitches every quarter inch or so—close enough that the weft won't shift, but not so close that you weaken the weft or waste thread. After every few stitches, pull the thread snug to keep tension even.
When you reach the end of the braid, tie off the thread and move to the next braid. Repeat until all braids are covered with wefted hair. The extensions should feel find and not slide when you gently tug on them.
Blending and styling your sew-in
Once all wefts are stitched down, comb through the extensions gently to blend them with your natural hair at the front. You can leave some of your natural hair out to frame your face, or blend it all in depending on the look you want. Style the hair as you normally would—straighten it, curl it, or leave it as is.
Some people explore heat to the extensions to blend the texture with their natural hair, but check the extension packaging first to see if they can handle heat. Synthetic hair cannot be heat-styled; human hair can be.
Caring for your sew-in to make it last
Sleep on a silk or satin pillowcase to reduce friction and frizz. Wash your hair every one to two weeks using a sulfate-free shampoo, focusing on the scalp and braids rather than the extension hair itself. Condition the extensions but avoid the roots and braids, where water and product can cause mildew or scalp irritation.
Avoid tight hairstyles that pull on the extensions or your natural hair. Don't sleep with wet hair, and try not to swim frequently because chlorine and salt water can dry out the extensions and cause tangling.
Itching and flaking at the scalp are common and usually mean you need to wash more often or the braids are too tight. If itching is severe or you see redness, remove the extensions and give your hair a break.
When and how to remove sew-ins safely
After four to eight weeks, the extensions should be removed. Your natural hair grows about half an inch per month, so the braids will loosen and the stitches may start to slip. Leaving extensions in too long increases the risk of traction alopecia, a type of hair loss caused by constant pulling on the hair roots.
To remove them, carefully cut the thread holding each weft using small scissors, then gently unravel the braids. This takes patience—rushing can break your natural hair. Once the braids are out, wash your hair thoroughly and deep condition it. Wait at least one to two weeks before installing new extensions so your scalp can recover and your natural hair can rest.
Common mistakes that damage your hair
The most common mistake is braiding too tightly. Your scalp should not hurt during or after installation. Tight braids cut off blood flow to the hair roots and can cause permanent hair loss along your hairline and edges.
Leaving extensions in too long is the second major mistake. After eight weeks, the weight of the extensions pulls harder on loosening braids, and your natural hair has grown enough that the tension increases. This is when traction alopecia develops.
Poor stitching that leaves gaps or loose wefts causes the extensions to slip and tug on your braids, which also damages your hair. If you're not confident in your stitching, paying a professional stylist is worth the cost to your hair health.
Frequently Asked Questions
Can I do a sew-in on very short natural hair?
You need at least two to three inches of natural hair to braid cornrows that will hold extensions. If your hair is shorter than that, the braids won't have enough length to anchor securely. You can wait for your hair to grow or consider clip-in extensions or a wig as alternatives.
How much does it cost to have a sew-in installed at a salon?
Installation costs vary widely by location and stylist experience, typically ranging from $100 to $300 or more. Hair bundles add to the cost. Doing it yourself saves money on labor but requires time and practice to avoid damaging your hair.
What if my scalp itches constantly after installation?
Itching usually means the braids are too tight, you need to wash more often, or product is building up on your scalp. Try washing every five to seven days instead of every two weeks. If itching continues or you see redness or flaking, remove the extensions and let your hair rest for at least two weeks.
Can I reuse the same wefted hair for another sew-in?
Yes, if the weft is still intact and the hair is in good condition. Carefully cut the thread and remove the weft from the old braids, then wash and condition the hair before reinstalling. Reusing hair saves money but requires that you handle removal gently so the weft doesn't tear.
How do I know if my sew-in is too tight?
Your scalp should feel firm but not painful. If you feel sharp pain, burning, or a constant ache, the braids are too tight. Loosen them when ready or have them redone. Mild soreness for the first day or two is normal, but it should fade quickly.