As a research architect at the Building Research Council of the University of Illinois, I am paid to solve some of the more nagging problems that houses have . Frequently , I visit troubled houses, troubled houses, and the most common problem I encounter is poor drainage away from the foundation .This problem became worse as wetlands were developed ; I know what to expect when the name of the developed : I know what to expect when the name of the development is Frog Hollow .
I was once asked yo looked at a house that had settling problems . An addition , built over a crawl space was moving down the relative to the main house. the dirt floor of the crawl space was even with the bottom of the footing. The soil along the of the footing . The soil along the edge along the edge of the footing was in small clumps, unlike the grainy fruity surface of the rest of the floor . I dug away a little more and found drain and found save that reminded me of a prison escape tunnel . In all, 10 ft. of the footing was under minded.
I call my studies of the zone where the house meets the ground building periodontics. Proper preventative care of this area can avoid a variety of problems, some less obvious and a lot more serious than a damp cellar.
For example , a common problem in basements particular those with block walls, is inward buckling . This usually shows up as a horizontal crack one or two blocks below grade , or at window walls , stepping up or down at the corners . A study I did with Illinois State Geological Survey revealed the cause . Clay soils shrink during spells forming a crevice between the soil and the foundation wall. Wind and light rains carry dirt into this crevice . Then, when seasonal rains come, the soils swells back to original dimension, plus the increment of added soil . Over time , the walls watched inward and eventually buckles. You avoid this problem by keeping the soil next to the foundation dry.
Slabs suffer from water problems , too. Garage floors, for example , commonly crack at the outside corners near where gutters drain. This cracking may be due to upward expansion of water directly below the corner. It can also be due to adhesion lifting of the perimeter wall, a situation occurring when saturated soil freezes fast to the foundation wall . The soil nearest the surface is the first freeze , and as the cold water continues , deeper soil freezes. This saturated soil by 8 percent as it freezes, exerting a tremendous force that lifts the soil frozen to the wall above. The wall lifts and cracks the slab .
Moisture damage around the foundations is not limited to masonry problems . In 1947 , Ralph Briton , the government researcher whose work led to current attic ventilation standards , showed that water vapor traveling upward from damp foundations caused moist attic moisture problems . He colluded that if attics are isolated from wet foundations, the standard 1:300 venting ratio could be reduced to 1:3000 .