What to Do If a Book Gets Wet: Emergency Drying Procedures

Water is the most immediately destructive force a book can encounter. A book that takes decades to deteriorate from heat, humidity, or light can be ruined by water in hours. Mould begins to grow on wet paper within 48 hours under warm conditions — often within 24. The pages swell, the binding distorts, inks run, and adhesives dissolve. Once mould establishes itself, removing it without trace is often impossible.

The good news is that prompt action can save most water-damaged books. The procedures are straightforward, require no special equipment, and are well within the capability of any careful person. But speed is everything.

Step 1: Assess the Situation (First 5 Minutes)

Before touching any books, assess the scale of the emergency:

Is the water source still active? A leaking pipe, ongoing flood, or rising groundwater must be addressed before salvage begins. Do not enter a room with standing water if there is any risk of electrical hazard.

How many books are affected? A single book is a simple rescue. Dozens or hundreds require triage — prioritising the most valuable and most salvageable items.

How wet are the books? The degree of saturation determines the appropriate drying method:

• Damp: Pages feel moist but are not visibly wet. The book can likely be air-dried.
• Wet: Pages are saturated but the book retains its shape. Air-drying or interleaving may work.
• Soaked: The book is thoroughly saturated and may be swollen or distorted. Freezing followed by professional treatment may be the best option.

Is the water clean or contaminated? Clean water (pipe leak, rain) is less damaging than sewage, floodwater, or fire-suppression water, which may contain contaminants that stain or further degrade materials.

Step 2: Triage (First 30 Minutes)

If multiple books are affected, prioritise:

1. Most valuable items first. A signed first edition worth $5,000 gets attention before a $10 reading copy.
2. Coated-paper books. Books printed on coated (glossy) paper — many art books, photography books, and illustrated volumes — are the most time-sensitive. When wet, coated paper pages fuse together permanently as they dry. These books must be treated immediately or frozen to prevent page-bonding.
3. Leather-bound books. Leather absorbs water and distorts irreversibly if dried too quickly. These require careful, controlled drying.
4. Books with water-soluble inks or illustrations. Watercolours, some early printed illustrations, and certain inks will run when wet. Minimise handling of these items.

Step 3: Immediate Actions for Individual Books

For damp books (slightly moist, not saturated)

1. Stand the book upright, fanned open. Place the book on a clean, absorbent surface (blotting paper, unprinted newsprint, paper towels) with the covers spread and the pages fanned. This allows air to circulate around the pages and promote evaporation.

2. Place absorbent material between pages. Interleave absorbent paper — paper towels, blotting paper, or unprinted newsprint — between every 20–30 pages. Do not use printed newspaper (the ink transfers). Change the interleaving material every few hours as it absorbs moisture.

3. Use a fan. Direct a gentle fan toward the books to increase air circulation. Do not use heat — hair dryers, radiators, or direct sunlight will cause rapid, uneven drying that warps boards and cockles pages.

4. Monitor for mould. Check the books every 12 hours. If you see any sign of mould growth — fuzzy spots, discolouration, musty smell — isolate the affected book and consult a conservator.

For wet books (saturated but holding shape)

1. Do not open the book fully. A saturated book is structurally weakened. Forcing it open can tear pages, break the spine, and detach the binding.

2. Drain excess water. Hold the book closed over a sink or basin and allow water to drain from the fore-edge and bottom. Do not squeeze or wring.

3. Interleave with absorbent material. Gently insert absorbent paper between groups of pages (every 20–30 pages). Work from the back of the book forward, supporting the text block to prevent distortion.

4. Stand upright to dry. Place the book on a clean, absorbent surface, standing upright with covers slightly open. Change the interleaving material frequently.

5. If drying is not possible within 48 hours, freeze the book. Freezing halts mould growth and buys time for professional treatment (see below).

For soaked books (thoroughly saturated, swollen, distorted)

1. Freeze immediately. Soaked books should be placed in a frost-free freezer as quickly as possible. Freezing stops mould growth, halts chemical reactions, and preserves the book in its current state until professional treatment can be arranged.

2. Wrap in waxed paper or plastic wrap before freezing. This prevents the pages from bonding to each other during freezing. Place each book in a separate wrapping.

3. Arrange for professional treatment. Soaked books are best treated by a professional conservator using vacuum freeze-drying — a technique that removes water from frozen books by sublimation (converting ice directly to vapor without passing through a liquid phase). This method minimises cockling, staining, and distortion.

Step 4: Drying Methods in Detail

Air drying

The simplest and most appropriate method for damp and moderately wet books. Requirements:

• A clean, dry, well-ventilated room
• Absorbent interleaving material (blotting paper or unprinted newsprint)
• Fans for air circulation
• Patience (air drying can take days to weeks)

Procedure: Interleave the book, stand it upright with covers fanned, and direct a gentle fan toward it. Change the interleaving material every few hours initially, then once or twice daily as the book dries. When the book feels dry to the touch, close it and place it under moderate weight (a few heavy books on top) to flatten any cockling. Leave under weight for several days.

Freezing and freeze-drying

For books that are too wet to air-dry safely, or when there are more books than can be dried within 48 hours:

Freezing: Place books in a frost-free freezer at -20°C (-4°F) or below. Books can remain frozen indefinitely — the freezer buys time.

Vacuum freeze-drying: A professional technique in which frozen books are placed in a vacuum chamber. The reduced pressure causes ice in the paper to sublimate (transition directly from solid to gas), removing water without the cockling and distortion that liquid evaporation causes. This is the gold standard for treating water-damaged books and is available through professional conservation facilities, commercial freeze-drying services, and some disaster recovery companies.

Step 5: After Drying

Once a book is dry, assess the damage:

Cockling. Some degree of page cockling (waviness) is almost inevitable after water exposure. Moderate cockling can be reduced by placing the book under weight for an extended period. Severe cockling may require professional flattening.

Staining. Water stains — the characteristic tide marks left by water as it dries — are permanent on most papers. A conservator can sometimes reduce their visibility through washing or bleaching, but these are interventional treatments with risks.

Binding damage. Water exposure weakens adhesives and swells boards. A book that appears structurally sound when wet may need rebinding or repair after drying.

Mould residue. If mould grew before or during drying, the spores remain even after the mould appears dormant. A conservator can treat mould-affected books to remove spores and prevent recurrence.

Odour. Musty odours from water damage and mould are extremely persistent. Activated charcoal, baking soda, or zeolite pouches placed in a sealed container with the book can absorb odours over time, but complete elimination is difficult.

Prevention

The best treatment for water damage is prevention:

• Never store valuable books in basements, regardless of how “dry” the basement seems. Basements flood.
• Ensure that rooms where books are stored have no overhead water pipes. If pipes are unavoidable, protect the books with waterproof covers or shelving with solid tops.
• Keep books on shelves at least 10cm (4 inches) above floor level, in case of minor flooding.
• Install water detection alarms near book storage areas.
• Maintain appropriate humidity levels (30–50% RH) to prevent the condensation that can cause localised water damage.
• Have a disaster plan. Know where the nearest frost-free freezer is, keep interleaving materials on hand, and have the contact information for a professional conservator readily available.

Water damage is a race against time. The collector who acts within the first 48 hours has a good chance of saving most affected books. The collector who waits will lose some of them to mould, distortion, and staining that no treatment can reverse.