Water damage may occur in homes through a variety of means including a burst pipe, a roof leak, fire sprinklers going off, torrential rains entering through the windows, and natural flooding. Water can be a destructive if not removed immediately since it can cause significant damages to different type of materials and items inside the home. One particular area in the home where water damage can have the most significant effect is the home library.

Effects of Water on Books and Unbound Materials

Water is absorbed by paper at different rates. The difference in rates depends on the age, condition, and the composition of the paper material. Some understanding of this water absorption of paper is important to essentially plan a successful document restoration and mold remediation of books with water damage. By understanding the process of water absorption, one can calculate beforehand the approximate amount of water which will have to be removed during the drying process and thus, providing helpful information in selecting the best drying method for the different types of books. Understanding the paper-water absorption process will also give the knowledge on the length of time each type of document material can be soaked in water before serious and irreversible water damage occurs.

Water damage to bound books usually takes place within one to four hours after they have been soaked in water. The greatest effect of water on bound books is the swelling of the pages and the book bindings because of the amount of water that is absorbed by the material. Since the paper inside the book and the cardboard cores of the book binding have a greater absorption capacity that the covering materials and the spine, the paper will expand or swell so much that it will cause the spine to bend or assume a concave shape which will cause the pages of the book to become partially or completely detached from the book binding. A book that has water damage should be handled carefully. How to handle the salvage process of books should be decided based on the amount of water absorbed by the pages and not by the relative humidity of the area. Water moisture meters can be used to measure water absorbed by books. If the water content is less than 7%, then the book is considered dry. Any reading higher than 7% is considered wet and has water damage.

In general, books, manuscripts and documents that were produced before 1840 will absorb water to an average of 80% their original weight. Some of these documents may even absorb as much as 200% their original weight. This is because of the high amounts of proteinaceous compounds that were used in making paper during those days. This means that the older and more valuable books will have the greatest amount of water damage when soaked. Modern books on the other hand, will absorb water at an average of 60% of their original weight.

When starting the drying process for books, compute the amount of water to be removed by using the percentage of water they can absorbed and multiplying it to the original weight of the book. For example, if a book's (modern book) average original weight is 4 pounds, then the average amount of water to be removed is 2.4 pounds. So if the home library has around 500 books with water damage, then the drying method should be able to handle the drying of 2000 pounds of paper material and extraction of 1200 pounds of water.