Older textiles and furnishings, especially those with a cellulosic fibre such as cotton, flax (linen), jute, and similar fibres, can slowly degrade over time—sometimes years or decades. This lengthy, slow but relentless deterioration and weakening of the fibres leads to eventual damage that can be seen as rips, tears, slits, or other structural damage in the fabric, carpet, or rug.
It may take a few years for dry rot to manifest itself, or it can take decades—sometimes 40-50 years or more. This misnomer, ‘dry rot,’ implies that the rotting or damage took place in the absence of moisture, whereas the damage was previously done during some conditions of wetness and mildew. It is understood that although presently “dry,” there were actually pre-existing conditions creating localised or smaller, concentrated areas of moisture build-up and damaging fungus growth therein. Once dry, the result is weakened fibres that can easily be broken and have a dry appearance, feel, or sound.
One condition that may have contributed to the onset of dry rot is prior, uncontrolled wetness for long periods of time. Typical of this is the section of rug or carpet underneath plant pots, especially planters made of clay, which can transpire moisture and dampness into the carpet. Another contributing factor may be residues in the base of the rug or carpet, such as those typical of animal pet stains. The build-up of salts from the pet stains becomes hygroscopic and thus “moisture attracting,” keeping that section slightly damp for long periods of time.
This condition in the textiles can thus cause moisture to be continually absorbed from the air and dampness to accumulate in the rug or fabric. The result is a slow but continual process of fungus growth and deterioration in the affected fibres, yarns, and rug or fabric. Rugs suffering from this condition may often smell during hot, humid weather.
The most common type of damage from dry rot occurs in cellulosic fibres that often make up the foundation (or unitary backing) of rugs and some woven carpet. Although the rug pile or face yarns may be wool or another fibre, it is actually the backing or foundation fibres that are more likely to be damaged.
This ongoing condition of dry rot shows no outward or obvious signs while the damage is slowly accumulating. That is, until the real damage is done and some normal moving or handling of the textile brings this latent condition to light. Eventually, the affected yarns become stiffer, less supple, and eventually brittleness sets in. This later condition typically results in a subtle but distinctive “crackling” or “snapping” sound when, for example, an older rug or carpet is bent or rolled between the hands.
Exceptionally fine quality, very dense, or tightly knotted oriental rugs are especially prone to such damage. In advanced conditions, merely lifting or moving the rug, textile, or fabric for cleaning or restoration can result in slits, rips, or tears in the foundation of the rug, carpet, tapestry, or fabric. It is not caused by the customary and normal handling but by the progressive “silent” damage that has been occurring for years before.
Unfortunately, there is no remedy to reverse this premature aging process in the affected fibres. The damage has already been done due to pre-existing conditions during use. The prescription is for a careful, thorough professional cleaning, and then any additional repairs needed to rebuild or reinforce the damaged area. An antimicrobial/antifungal treatment to arrest some of the inherent conditions leading to damage may also be considered. However, there is no assurance that the dry rot will not appear again in the same or other areas of your rug or textile in the future.
