What raising action means and why you might need to do it

Action is the distance between the strings and the fretboard. Raising action means increasing that gap so the strings sit higher above the wood. You do this by replacing or shimming the nut (the bone or plastic piece at the headstock end) or the bridge (the wooden piece glued to the body where strings anchor). Most players raise action when strings buzz against the frets, when the neck has too much forward curve, or when they want a thicker, louder tone that comes from strings vibrating with more clearance.

Acoustic guitars need higher action than electric guitars because the strings vibrate in a wider arc and can rattle against frets if the gap is too small. Factory action is often set low to make the guitar easier to play in the store, but many players find it buzzes in real use. Raising action fixes that buzz and gives you a guitar that rings cleanly.

Key Takeaways

  • The nut controls action at the headstock end; the bridge controls it at the body end, and you usually need to raise both to fix buzz across the whole neck.
  • Replacing the nut is the most permanent fix but requires removing the old one without damaging the headstock, then fitting a new one precisely.
  • Shimming the bridge (gluing a thin wood shim under it) is faster and reversible, though it changes the neck angle slightly and may affect tone.
  • Raising action at the bridge more than 1/8 inch usually requires a new nut at the headstock to keep the strings aligned, or playability suffers.
  • You can measure action with a straightedge and ruler at the 12th fret to know exactly how much you need to raise it.

Measuring your current action before you start

Before you change anything, measure what you have. Place a metal straightedge flat across the frets from the first fret to the last fret, then use a ruler to measure the gap between the bottom of the straightedge and the top of the string at the 12th fret (the middle of the neck). Measure both the bass string (thickest) and the treble string (thinnest) separately—they should be close to equal, but often the bass side is slightly higher.

Write down both numbers. Most acoustic guitars ship with action around 2.0 to 2.2 mm on the treble side and 2.5 to 2.7 mm on the bass side. If your guitar buzzes and the action is below 1.8 mm on either side, raising it will likely fix the problem. If the action is already above 2.5 mm and you still hear buzz, the issue is probably a dip in the neck, not low action, and raising the bridge alone will not help.

Replacing the nut for a permanent fix

The nut is a small piece (usually 1.5 to 2 inches long) that sits in a slot at the headstock where the frets end. It has grooves cut into it for each string. Replacing it is the cleanest way to raise action at the headstock end, but it requires care to avoid damaging the headstock.

First, loosen the tuning pegs and remove all string tension. Use a heat gun or hair dryer on low heat to warm the nut for 30 to 60 seconds—this softens the glue. Tap a thin chisel or old butter knife gently under the nut from the side, working it back and forth until it lifts free. Do not pry straight up; that can split the headstock. Once the nut is out, scrape away old glue with the chisel, then sand the slot smooth with 120-grit sandpaper.

Measure the slot width, length, and depth. Order a blank nut (uncut bone or plastic) that matches those dimensions. Bone sounds better than plastic and lasts longer, but plastic is cheaper and easier to shape if you make a mistake. Glue the new nut into the slot using hide glue or epoxy, clamp it with a caul (a flat piece of wood) and light pressure for 24 hours, then cut the string grooves to match your string gauges. This step is fiddly—if you are not confident with a file, have a repair shop cut the grooves for you.

Shimming the bridge to raise action quickly

Shimming is faster and reversible: you glue a thin piece of wood (usually 1/16 to 1/8 inch thick) under the bridge to tilt it up. This raises action at the body end without removing anything.

First, loosen the strings enough to remove them completely. Mark the bridge location with a pencil so you can align the shim. Use a heat gun to warm the bridge for 60 to 90 seconds, then carefully tap a thin chisel under one corner and work it free. Do not pry hard; the bridge is glued with hide glue, which softens with heat. Once it lifts, scrape away old glue from both the bridge and the guitar body.

Cut a shim from hardwood (maple or spruce) that is slightly smaller than the bridge footprint and 1/16 to 1/8 inch thick. Glue it to the body with hide glue or epoxy, then glue the bridge back on top, aligned with your pencil marks. Clamp with even pressure across the whole bridge for 24 hours. Restring and tune to pitch, then measure action again. If you need more height, you can add another shim, though more than two shims usually means the neck angle is too shallow and a nut replacement is a better fix.

How much to raise action and what to expect

Most players find 2.0 to 2.2 mm on the treble side and 2.5 to 2.7 mm on the bass side comfortable for fingerstyle and strumming without buzz. If you raise action more than 1/8 inch (about 3.2 mm) at the bridge, the strings will be very high and hard to press down, and you will likely need a new nut to keep the strings aligned and playable.

Raising action does change tone—higher action usually means a louder, fuller sound because the strings vibrate more freely. It also means more finger pressure is needed to fret notes cleanly, which can tire your hand on long playing sessions. Start with a small raise (1/16 inch) and play for a week before deciding if you need more. You can always raise it further, but lowering it again requires removing the shim or replacing the nut again.

Common mistakes to avoid when raising action

The biggest mistake is raising only the bridge without raising the nut. If the bridge goes up but the nut stays low, the strings angle sharply from the nut to the bridge, and the high strings will buzz against the frets near the headstock even though the bridge end is clear. Always raise both the nut and the bridge together, or measure carefully to make sure the nut is already high enough.

Another common error is using the wrong glue. Hide glue (also called hot glue or animal glue) is traditional and reversible with heat, which makes it ideal for guitar work. Epoxy is permanent and stronger, but if you make a mistake or want to undo the work later, epoxy is much harder to remove. Avoid wood glue (like Titebond) for this job—it dries too fast and does not bond well to old glue residue.

Do not sand or file the bridge or nut while it is glued to the guitar. Remove it first, work on it on a bench, then glue it back. Sanding while glued risks damaging the finish or the headstock. Also, do not raise action more than 1/4 inch at once; the neck angle may not support it, and playability will suffer. Small, measured steps are safer and let you hear the difference each change makes.

When to have a repair shop do the work instead

If your guitar has a dip or backbow in the neck (not just low action), raising the bridge alone will not fix it. A repair shop can check the neck with a straightedge and either adjust the truss rod or plane the frets to flatten the neck. This is specialized work that requires tools and skill most home players do not have.

If you are uncomfortable with heat guns, chisels, and glue, or if your guitar is valuable or vintage, a repair shop is the safer choice. A professional can measure your neck, cut a new nut with proper string spacing, and shim or replace the bridge in a few hours. The cost is usually 75 to 150 dollars, which is worth it if you avoid damaging a guitar you love.

Frequently Asked Questions

Can I raise action without removing the strings?

You can shim the bridge without fully removing strings if you loosen them enough to lift the bridge, but you cannot replace the nut without removing all string tension first. Loosening strings also makes it easier to work and reduces the risk of the headstock cracking when you remove the nut.

How long does it take to raise action?

Shimming the bridge takes 2 to 4 hours if you work slowly and let glue dry between steps. Replacing the nut takes 4 to 6 hours if you cut the grooves yourself, or 1 to 2 hours if you have a shop cut them. Hide glue needs 24 hours to cure fully before you tune to pitch.

Will raising action hurt the resale value of my guitar?

No. Raising action is a normal maintenance task, and most players expect to adjust it over time. A guitar with clean, high action is actually more desirable than one with factory-low action that buzzes. Keep the old nut if you remove it, in case a future owner wants to restore the original setup.

What if I raise the action and it still buzzes?

Buzz that persists after raising action usually means the neck has a dip or the frets are worn unevenly. A straightedge laid across the frets will show this—if there is a gap under the straightedge in the middle of the neck, the frets need leveling. This is a job for a repair shop with a fret crowning file.

Can I use a shim that is thicker than 1/8 inch?

You can, but it changes the neck angle significantly and may affect tone and playability. Shims thicker than 1/8 inch usually mean the nut needs to be raised too, or the strings will angle too sharply and buzz near the headstock. Two thin shims (1/16 inch each) are better than one thick one.