What Happens When a Piano Soundboard Cracks?

Understanding the Piano Soundboard

The soundboard is often called the heart of the piano. It’s a large, thin wooden board (traditionally spruce) that amplifies the vibrations of the piano’s strings into a rich, resonant sound. In a grand piano, the soundboard is a horizontal plate underneath the strings; in an upright piano, it stands vertically at the back. If you peek inside a piano (grand or upright), you’ll see a broad sheet of wood behind the iron plate – that’s the soundboard, and it’s imperative for projecting the piano’s sound by turning string vibrations into audible music. Without a functioning soundboard, the strings alone would produce a faint, tinny jingle.

The soundboard works by vibrating in sympathy with the strings. When a key is pressed, the hammer strikes a string, and the string’s vibration is transferred through the bridge (a wooden ridge attached to the soundboard) into the soundboard. The soundboard’s large surface then vibrates the air, amplifying the sound much like a speaker or the top of a guitar. High-quality spruce is used because it has long straight fibers and excellent resonance, allowing the soundboard to sustain and project tones effectively. Moreover, soundboards are built with a slight upward curvature called the “crown” in the middle, supported by wooden ribs underneath. This crown and rib structure give the board strength and improve its tonal response. Overall, the soundboard is a critical component that greatly influences a piano’s volume and tonal richness.

Why Do Piano Soundboards Crack?

Piano soundboards are made of wood, so they are subject to the natural expansion and contraction that wood undergoes with humidity and temperature changes. Over time, it’s common for soundboards to develop cracks due to these environmental stresses. When the air is dry (low humidity), the wooden soundboard shrinks; when it’s humid, the wood swells. These repeated seasonal changes put stress on the wood. If the wood dries out excessively or suddenly, it can split along the grain – this is essentially what a soundboard crack is. In fact, nearly all pianos eventually develop small cracks in the soundboard over their lifetimes, especially in climates with significant humidity swings. This often happens after years of vibration plus cyclical weather changes that dry out the wood and the glue joints holding the soundboard planks together. Small separations can appear where the soundboard’s wooden panels are joined (called split seams), or cracks can form along the grain of the wood itself between the seams.

Normal aging and use can lead to hairline cracks that many pianos have without any serious issues. However, not all cracks are due to slow climate wear-and-tear. Sometimes, a significant shock or trauma to the piano can cause a more dramatic crack. For example, dropping a piano or mishandling it during a move can jolt the soundboard and cause substantial splits. Such cracks from impact tend to be larger and more severe – they might even split the board into separate sections if extreme. A piano that has suffered great climatic extremes or physical trauma may show extensive soundboard cracking. In these cases, the cracks are a red flag that the piano was stressed beyond normal conditions, and the instrument’s overall health and longevity might be compromised. In other words, a lot of wide or numerous cracks can indicate the piano lived in a very dry environment (or went through rapid humidity changes), and its life expectancy may be short if multiple components have been damaged by that exposure. (Often you’ll find other symptoms of climate damage in such pianos, like loose tuning pins, loose glue joints, or cracked bridges, not just the soundboard cracks.)

It’s worth noting that piano manufacturers and technicians try to mitigate cracking by using well-seasoned wood and by recommending stable humidity for piano care. But despite the best construction, wood is wood – if the soundboard’s wooden planks shrink from dryness, cracks will form. That’s why controlling a piano’s environment (using humidifiers/dehumidifiers or a piano climate control system) is important to preserve the soundboard.

Are All Soundboard Cracks Serious?

Seeing a crack in a piano’s soundboard can be alarming, but not all cracks are catastrophic. There is a common misconception (especially among piano owners and shoppers) that a cracked soundboard is a piano’s death sentence – that the piano is ruined or can’t be tuned anymore. In reality, that’s a myth and “neither is necessarily true at all”. Many older pianos have cracked soundboards yet continue to play well and hold their tuning just fine.

Small or hairline cracks (including those thin separations along glue joints) are often cosmetic or minor. These typically occur as the piano ages and experiences normal humidity cycles. Technicians note that such cracks “rarely are these cracks serious enough to cause any bother” in terms of the piano’s performance. In other words, a minor crack does not automatically ruin the sound or functionality of the piano. If the piano still has a good tone and no strange noises, a crack might be essentially harmless. Contrary to popular belief, cracks in the soundboard are not necessarily important as long as the tone is acceptable. Many pianists and techs can point to instruments with multiple small cracks that still sound beautiful.

On the other hand, certain types of cracks are more severe and can lead to problems. The worst scenario is when a crack causes the soundboard to detach from its supporting ribs or the bridges, because that can affect the structural tension and create buzzing noises. The soundboard is reinforced by wooden ribs (1-inch or so wide strips) that run perpendicular across its back (visible on the back of an upright or underside of a grand) to support its crown and stability. If a crack runs under a rib and the glue joint between the rib and board gives way, the rib can separate at that crack. Any separation of a rib from the soundboard at a crack is a potential source of buzzing or rattling noises when the piano is played. This is one case where a crack is not just cosmetic – you’ll actually hear a nasty buzz or distortion as the loose parts vibrate. Similarly, a crack that runs into or underneath the bridges (the wooden rails on top of the soundboard that hold the strings) is more serious. The bridges transmit string vibration to the soundboard, so if a crack loosens a bridge’s attachment or splits right through a bridge, it can compromise the piano’s tone and tuning stability in that section. A crack passing through a bridge might mean the bridge itself isn’t firmly anchored, which could lead to buzzing or changes in how the strings sound, and it’s a more complex repair to resolve.

Width and length of the crack also matter. Tiny hairline cracks or slight seam separations that you can barely even fit a piece of paper into are usually not a big deal. But if the crack is gaping wide (for instance, as wide as a coin like a penny in extreme cases) or runs a very long span across the board, it suggests more significant movement of the wood. Large cracks that physically split the soundboard into distinct sections can definitely affect the piano. Often, these big cracks are accompanied by the loss of the soundboard’s crown (the board may become flatter in that area), which can dull the tone.

In summary, not all cracks are “bad”. Many are common and have little to no audible effect, whereas others can indicate or cause real issues. A rule of thumb from piano technicians: a crack or seam separation is of little consequence as long as it doesn’t rattle or buzz. If you don’t hear any problems, the crack is likely not severe. But if you do hear buzzing, or if the crack is clearly affecting structural elements like ribs or bridges, then it’s a more serious matter.

Effects of a Cracked Soundboard on Tone and Structure

One of the biggest questions buyers have is: Does a cracked soundboard change the way a piano sounds? The answer is a bit nuanced. In theory, any crack (and the conditions that cause it, like loss of crown) can reduce the soundboard’s ability to vibrate optimally, leading to a deterioration of tonal quality. However, in practice the actual results vary greatly from piano to piano. Many pianos with small cracks continue to have excellent tone and sustain. As one expert notes, although a crack might make a measurable difference, the change in sound is usually so slight as to be nearly imperceptible to the human ear. In fact, the overall design, materials, and condition of the piano tend to matter more for tone than a couple of hairline cracks.

If a soundboard crack has not compromised the piano’s crown or caused any parts to loosen, the tone may remain virtually unchanged. The piano will still produce full sound because the soundboard can still vibrate as a whole. This is why an old grand piano with a few stable cracks can still sound wonderfully warm – the cracks might not be doing much harm at all. As long as the sound of the piano is rich and acceptable to your ears, a crack is not necessarily a problem. It’s quite possible you wouldn’t even know a soundboard was cracked just by listening, especially if the cracks are small.

However, there are scenarios where tone can be affected. If the soundboard has lost a lot of its crown (curvature) due to age and dryness (often accompanied by multiple cracks), the piano’s sound might become a bit muted or less resonant. A flattened soundboard doesn’t have the same energy “push-back” against the strings, which can reduce the fullness of tone and the sustain of notes. Cracks often appear as a solid spruce soundboard loses its crown over time, so extensive cracking can be a symptom of a board that’s no longer optimally shaped for sound. Additionally, if a crack causes part of the soundboard to vibrate independently (for example, a section between two cracks not moving in unison with the rest of the board), there could be slight tonal coloration or a very subtle noise.

The most obvious tonal problem caused by cracks is the buzzing/rattling noise mentioned earlier. This happens if a crack leads to a loose rib or a fragment of wood that vibrates against another piece. Such a buzz is usually noticeable on certain notes or ranges of the keyboard and is a clear sign the crack needs attention.

In terms of structural integrity, a cracked soundboard does not mean the piano is structurally falling apart. The soundboard’s job is to amplify sound, not to hold the piano together – the heavy cast iron plate and wooden frame structure handle the overall structural load. So a crack in the soundboard won’t make the piano collapse or anything dramatic. That said, extensive cracking can be a symptom of other structural issues as noted. If a piano lived through extremely dry conditions, not only the soundboard but also other wooden parts (like the pinblock that holds tuning pins, or the bridges, or even the case joints) might have issues. In a worst-case scenario (say, a piano dropped from a height or in a flood), a shattered soundboard would be part of a larger pattern of damage that could render the piano unusable without major restoration. But those cases are relatively rare.

To put it simply, a single crack by itself usually has minimal effect on a piano’s tone and no effect on its ability to be tuned, unless it’s accompanied by specific problems (like rib or bridge issues). Pianos can and do play with cracked soundboards for decades. Yet, a cracked soundboard can indirectly signal reduced value or future repair needs, which is why it’s taken into account in piano appraisals (more on that below). Each instrument must be evaluated on its own merits – some cracked soundboards still perform wonderfully, whereas others with similar cracks might not, depending on the piano’s overall condition.

Evaluating a Piano with a Cracked Soundboard (Is It Still Worth Buying?)

If you encounter a used piano that has a cracked soundboard, you’ll want to evaluate whether that piano is still a good purchase. The short answer: it depends on the severity of the crack and the quality of the piano. Here are some key factors to consider when evaluating a piano with a cracked soundboard:

Severity and Location of the Crack: Examine how big the crack is and where it’s located. Is it a small hairline crack off to the edge, or a long split running across the board? A single small crack off to the side is far less concerning than multiple wide cracks or a crack that goes right through the area under the bridges. If the crack is very extensive (especially if you see several cracks like a spiderweb), it could indicate the piano went through harsh conditions and might have a shorter life expectancy ahead. Also check (or have a technician check) if the crack has caused any rib separations by looking at the back of an upright or the underside of a grand – if a rib is loose, you might see or feel a slight gap at the crack line, or hear a buzz when pressing that area. Similarly, inspect around the bridges on the soundboard; cracks directly through a bridge or adjacent to it are more worrisome. If you’re not sure, make a note to ask a piano technician about these specifics.
Effect on Tone: Play the piano across all registers. Listen for any buzzing, rattling, or loss of tonal quality. If the piano sounds good to you and has no mysterious noises, that’s a great sign that the crack hasn’t materially affected its musical performance. Remember, a crack is “of little consequence as long as it doesn’t rattle” and the tone remains pleasing. If the piano has a beautiful tone and sustain, a crack may be a non-issue. On the other hand, if you notice a dullness in certain notes or a buzz, pinpoint where it’s coming from – it could be related to the crack (for instance, a buzz could mean a loose rib at that spot).
Age and Climate History: Consider the piano’s age and environment. Older pianos (say 50+ years) frequently have some soundboard cracks simply due to wood aging and decades of seasonal changes – in a well-maintained piano this might be “par for the course” and not a deal-breaker. However, if a relatively newer piano has a cracked board, it might indicate it was kept in a poor environment (too dry or drastic climate changes). It’s helpful to ask the seller or look for clues about how the piano was stored. A piano that lived in a stable, climate-controlled home is less likely to have extreme damage than one kept in an unheated garage or near a radiator (which is notorious for drying out wood and causing cracks). Multiple parallel cracks in the board, or cracks accompanied by things like a loose tuning pinblock or rusty strings, might hint that the piano suffered humidity extremes and could have other issues.
Piano’s Brand and Build Quality: The brand and model matter in two ways. First, a higher-end piano (Steinway, Petrof, Mason & Hamlin, Bösendorfer, etc.) with a cracked soundboard might still be worth investing in or repairing because the underlying instrument is valuable. For instance, a vintage Steinway with one crack could still be a great piano and even if you needed to repair or replace the soundboard down the line, the piano’s value might justify it. In contrast, a very old spinet of a lesser-known brand with a cracked board might not be worth expensive repairs – you might just use it as-is if it plays, but it has little resale value. Also, some brands use different soundboard designs (e.g., certain newer pianos have multi-ply boards or different crown systems) that might make them more or less prone to cracks.
Cost of Repair vs. Value: It’s important to weigh how much it would cost to fix a problematic crack (if it indeed needs fixing) against the piano’s price and value. Repairing a cracked soundboard can be very expensive – often it means a major restoration task of removing the piano’s plate and either shimming the crack or replacing the board entirely. In many cases this is not worth doing unless the piano is of very high quality or great sentimental value. For example, spending many thousands to replace a soundboard might be justified on a Steinway concert grand or a family heirloom, but it wouldn’t make sense on a low-end upright that you can replace for less than the repair cost. If the piano in question is modestly priced (or free) and has a crack, as a buyer you should factor in that you likely won’t repair the crack – you’ll either live with it or pass on the piano. On the flip side, if you’re looking at a top-tier piano being sold at a big discount because of a crack, it might be worth it since you’re getting a deal, and the piano might still play fine for years before any major intervention is needed (if ever).
Previous Repairs: Take a look at the soundboard to see if there’s evidence of prior crack repairs. Technicians often repair soundboard cracks by shimming – inserting thin wooden splines to fill a crack – or by gluing. If you notice skinny wooden strips filling a split, or irregular lines that have been filled in, it means someone has repaired the crack in the past. This isn’t necessarily a bad thing; in fact, it indicates the piano was rebuilt or repaired at some point, presumably by a professional. A well-done shim can restore the board’s integrity and may eliminate any buzz that was there. If the piano has had such restoration work, find out who did it and when, as that can tell you about the care the instrument received.
Stability and Other Factors: Consider whether the crack seems stable or if it might get worse. This is hard to determine on your own in one viewing, but a technician can sometimes tell if a crack is old (darkened edges, perhaps already glued) or fresh. You can also gently press on the area around the crack – if the soundboard flexes or the crack widens, that’s not a great sign (don’t press too hard though). Also check the piano’s tuning stability – a cracked board by itself doesn’t cause tuning issues (tuning is more about pinblock and strings), but if the piano won’t hold a tune, that indicates other problems. Often a crack is a negotiation point in price: even if it’s not harming the sound, buyers fear it, so the resale value is usually lower than a similar piano with no cracks. This means you as a buyer might acquire a otherwise good piano for less money due to the cosmetic stigma of a crack. Just be sure it truly is otherwise good by checking it out thoroughly.

Finally, always consider consulting a professional piano technician before buying any used piano with a known issue like a cracked soundboard. An experienced technician can assess the severity of the crack and spot any related problems that an untrained eye might miss. If you notice a soundboard crack in a piano you are thinking of buying, it’s wise to have a qualified tech inspect it first – this is generally a low-cost service that can save you from surprises. The technician will check for things like rib separations, loss of crown, or structural problems around the crack and give you an expert opinion on whether it’s a concern or not. In many cases, the tech might say “Yes, the board has a crack, but it’s stable and the piano sounds good,” which can put your mind at ease. Or they might warn you if it’s a severe issue that would require repair.

When to Ignore a Soundboard Crack vs. When It Needs Attention

From a maintenance perspective, when can a cracked soundboard be left alone, and when does it require repair? The answer lies in whether the crack is actually causing any problems.

You can often ignore minor soundboard cracks that are not affecting the piano’s sound or structural function. For instance, thin cracks or seam splits with no buzzing and no movement can be left as-is. They may open slightly in dry winters and close up in more humid summers (this natural breathing of the wood is normal). Many technicians will note these cracks during a tuning but take a “wait and see” approach – basically, monitor them over time rather than immediately fix. As one piano service puts it, some cracks “may not even need any immediate intervention, but simply analysis and monitoring”. If a crack isn’t growing or causing noise, there’s little harm in just keeping an eye (or ear) on it. Pianos can live long, musical lives with such minor cracks present.

Examples of cracks that can usually be ignored:

A short hairline crack at the edge of the soundboard far from the bridges.
A narrow split along a glue joint (seam) that doesn’t go under any ribs.
Older, well-established cracks that have remained unchanged for years and produce no buzz.
Cracks that have been professionally shimmed/repaired in the past (if the repair is holding up, you don’t need to redo it).

In these cases, you might do nothing more than ensure the piano’s humidity is kept stable to prevent the crack from widening. Technicians might check the crack during regular service appointments to make sure it’s not worsening. It’s also worth noting that if a crack is purely cosmetic, fixing it (which can be very involved) might not make any audible difference, so many owners opt not to fix such cracks in older pianos where a cosmetic issue doesn’t justify an expensive repair.

On the flip side, certain cracks need prompt attention from a piano technician or rebuilder:

If you hear buzzing or rattling that you’ve traced to a crack area, the crack likely needs to be addressed. The technician might re-glue a loose rib or shim the crack to stop the noise.
If a crack has caused a rib to separate or detach, it should be repaired. Typically, the fix is to glue and clamp the rib back down and fill the crack beneath so it’s solidly attached again. This can usually be done without a full rebuild – it’s a moderate repair cost and will restore the proper contact and stop noises.
If a crack runs under a bridge and seems to affect the stability of that bridge, a repair is important. This might involve injecting glue under the bridge or in worst cases removing and reattaching the bridge after fixing the board, to ensure the bridge is firmly connected to the soundboard. Ignoring a crack under a bridge could lead to tuning or tonal issues in that section of the piano if the bridge can’t transmit vibrations effectively.
Large or widening cracks in general merit repair, especially if you notice them getting bigger over time. A technician can insert wooden shims (pieces of spruce) into the crack to seal it up and then re-varnish that area. Shimming a crack restores the continuity of the soundboard and can often be done when the piano is apart for other work (though it’s a labor-intensive job).
If the piano has extensive damage (e.g. multiple major cracks, or cracks associated with a fallen soundboard crown), and the instrument is valuable enough, you might consider a soundboard replacement. This is the most extreme fix – essentially a piano rebuild where the entire soundboard is removed and a new one is custom-fit. This is only done in cases where the piano’s value and performance goals justify it (for example, restoring a high-end grand piano). For a typical home upright or baby grand, replacement is rarely on the table because of the cost. Often, partial repairs (like shimming a couple cracks and reattaching ribs) can suffice if needed.

In summary, ignore the crack if it’s not hurting anything (just keep the piano in good humidity to avoid further issues), but address it if it causes audible problems or threatens key structural contacts (ribs/bridges). And remember, a competent piano technician can usually fix many crack-related problems without replacing the whole board – for example, gluing a rib or shimming a crack can be done at a “reasonable cost without rebuilding the piano”, especially compared to a full soundboard replacement. So if you love the piano and it has a buzz, don’t despair – these issues can often be repaired successfully.

Recommendations for Piano Buyers Confronting a Cracked Soundboard

If you’re a piano buyer who discovers a soundboard crack, here are some buyer-oriented tips to guide you:

Don’t Panic – Assess the Piano Calmly: A cracked soundboard is not automatically a deal-breaker. Many pianos have them and still play beautifully. Take a deep breath and remember that “cracked soundboard” horror stories are often exaggerated. Focus on the overall condition of the piano.
Play and Listen Carefully: Test the piano across all registers and dynamics. Listen for any unusual buzzes, rattles, or weak-sounding areas. If the piano delivers a pleasing tone and you don’t hear any noise artifacts, the crack likely isn’t causing functional issues. A piano that sounds great despite a crack is a good sign. If you do hear a problem, make note of it – it could be related to the crack (and might be fixable), or it could be something else entirely.
Get a Professional Inspection: Before finalizing a purchase, have a piano technician examine the instrument. A tech can confirm whether the crack is minor or serious. They will check things like the soundboard crown, rib glue joints, and bridge attachment around the crack. This expert evaluation will give you peace of mind (or alert you to walk away if there’s a hidden major issue). The small fee for an inspection is well worth it when buying a used piano, cracked board or not.
Consider the Piano’s Purpose and Value: Think about what you want from this piano. If you’re looking for a top-notch performance instrument or a long-term investment, you may lean toward pianos in excellent condition (and might skip one with a significant crack unless it’s a high-end model at a great price). If you just need a decent piano for learning or casual play, a crack that doesn’t affect the sound might be perfectly acceptable – and could save you money. Also, factor in the brand and age: a small crack in a high-quality, coveted brand piano may be less concerning (and more worth accommodating) than a crack in a very old, lower-end piano that has other limitations.
Use the Crack as a Negotiation Point: A soundboard crack typically lowers a piano’s resale value because many buyers shy away from it. If you’re willing to live with the crack, you can often negotiate a better price. Be polite but candid with the seller – mention that the crack is a concern and that you’ll likely need to have a tech look at it or potentially repair it in the future. This can justify a lower offer. That said, if the seller has documentation from a technician saying the crack is non-issue, take that into account as well.
Plan for Maintenance, Not Major Repair (in Most Cases): If you buy the piano, maintain a stable environment for it. Invest in a simple humidifier/dehumidifier system or room hygrometer to keep humidity around the piano steady (around 40-50% is often recommended). This will help prevent existing cracks from worsening and avoid new ones. During regular tunings, ask your technician to keep an eye (and ear) on the crack. Unless the crack starts causing a problem, you generally won’t need to “fix” it. Remember that repairing a soundboard crack is usually a large operation not undertaken except in high-end restorations. So, don’t plan on replacing the soundboard unless you absolutely must; instead, enjoy the piano as is, and address any small issues (like a loose rib causing a buzz) with relatively minor repairs if they arise.
Know When to Walk Away: While most soundboard cracks are manageable, there are rare cases you might decide not to proceed with a purchase. For example, if the piano has multiple serious cracks plus other evident problems (like it won’t hold a tune, or the bridges are splitting, etc.), you might be looking at an instrument requiring extensive rebuilding. If the cost of needed repairs approaches or exceeds the price of a better-condition piano, walking away could be the wisest choice. A piano is a sum of many parts – if a crack is one of many red flags, trust your instincts (and your technician’s advice) about the overall health of the piano.

Bottom line for buyers: A cracked soundboard should invite some caution and further inquiry, but it’s often not the end of the world. Many pianos with soundboard cracks still perform well, and technicians frequently regard small cracks as a normal part of a piano’s aging process. By focusing on the piano’s actual performance and getting expert advice, you can make an informed decision. Whether you choose to buy a piano with a crack will depend on the specifics, but armed with the above knowledge, you won’t be unduly alarmed. Instead, you’ll understand what the crack means, know how to evaluate its impact, and be able to proceed in the best interest of your musical investment.