When wood continually becomes wet and can't dry out because of poor ventilation, dry rot can grow. Causes of the dampness and dry rots include: inadequate waterproofing of the wood; condensation; leaking washing machines; leaking plumbing such as pipes, showers or sink taps; dampness; and holes or cracks in the roof. Dry rot can develop if you don't sterilize your home's masonry.
If you suspect you have dry rot growing inside your home, examine the walls, ceilings, floors and spaces beneath your sinks for signs of the fungus. Walls and ceilings will display discoloration such as water spots. Also, notice the wrinkling, sagging or crumbling of any sheet-rock in the home. When examining carpeted floors, look for discoloration, particularly near outer walls. If you have vinyl floors, check for gray or black discoloration. You may notice that your floors warp or ripple.
The exterior of your house may display signs of dry rot and alert you to the problem. Examine your siding for any warping or swelling. Bubbling paint may also indicate a dry rot problem. Get a ladder out and look at your roof's eaves or fascia boards. If the ends of the fascia boards feel soft or are crumbling, you have a problem. Test any exposed wood with a screw driver. Try to push the tool into the wood. Wood that's easy to puncture likely has dry rot.
Dry rot gives off a musty, damp odor. Since dry rot is a fungus, you may actually see fungus growths on the wood. A gray coating forms on the wood and sprouts patches of light purple and yellow mushrooms-like bodies. Dry rot produces spore dust that is the color of red rust or red brick. You may also notice sheets of cottony wool form on any brickwork or the wood itself. A sign of dry rot may also be an increase of insects such as ants and termitesand sawdust. The moisture of the wood attracts these insects. They suck the water from the wood and turn timber into sawdust.
Rather than repair dry rot, prevent it. Waterproof your home, especially the bathroom, kitchen and laundry room. Take steps to see that water can't get in through seals around windows and doors or through the roof. If the wood in your home does become damp, give it ventilation to dry it out. Install ventilation throughout the home but especially in the roof and basement.