Figure 1 - Poured concrete foundation and walls

The cost of repairs to foundations almost always exceeds the cost of better construction practices implemented at the time of the original construction.

Table 1 identifies and provides solutions to many of the problems typically seen in the foundations of newly constructed houses. The solutions provided represent the better design and building practices being applied by leading builders and the best practical advice being offered by building researchers, professional associations and the home building industry.

In many cases they reflect building code requirements and in other instances, the solutions offered represent practices that go beyond minimum requirements, providing additional protection against potential defects and callback costs.

Table 1 - Problems & Solutions Found In House Foundations

• Concrete Foundation Walls
• Structural Deterioration And Damage
• Cracks and spalling from under-strength concrete
• Insufficient design strength
• Cracks and spalling from under-designed concrete.
• Inadequate dimensions
• Cracks in foundations and slabs resulting from settlement and movement
• Inadequate bearing
• Cracks and spalling from poor construction practices
• Poor placement and finishing techniques
• Over watering
• Improper curing of concrete
• Inadequate cold weather protection - below 41°F (5°C)
• Inadequate hot weather precautions - above 85°F (30°C)
• Shrinkage cracks
• Normal drying of concrete
• Cracks in foundations and slabs resulting from settlement and movement
• Differential movement
• Differential movement and cracking of the garage slab
• Problem soils
• Cracks in foundations and slabs resulting from frost heaving and freezing
• Footings not extending below the frost line
• Moisture in soil adhering to the foundation wall and the lifting foundation
• Deterioration from salt attack
• Weak, permeable concrete
• Water Leakage
• Water leakage through foundations
• Inadequate site drainage
• Improperly installed drainage tile
• Leakage through form-tie holes
• Condensation on interior of foundation walls
• Inadequate damp-proofing
• Humid, damp, or, musty basement or crawl space
• Entry of soil vapor through cracks in the floor slab or foundation walls
• Moisture in crawl spaces
• Moisture damage to interior insulated foundation walls.
• Air leakage behind insulation
• Creep and movement of exterior foundation insulation above grade
• Frost adhesion
• Soil settlement around foundation

• Slabs-on-ground
• Structural Deterioration And Damage
• Cracking of slab
• Differential or uneven settlement.
• Curling of the slab
• Inadequate structural strength of slab
• Frost heave
• Water Leakage
• Damp or wet floor slab
• Moisture migration up through the slab
• Insulation
• Cold Floors
• Heat loss from the slab

Concrete Foundation Walls - Introduction

Concrete foundations are the predominant foundation type in new home construction, especially in harsher climates in the Northern US and Canada. They encompass poured concrete walls and concrete block walls. When proper construction techniques are used, these tow types of foundation can be durable and defect-free. However, when poor construction techniques are applied, costly construction defects are likely to result.

The major problems can be divided into two categories:

• Those which result in structural deterioration and damage.
• Those which result in water leakage and moisture damage.

The causes of their difficulties are often similar.

To reduce the likelihood of problems, builders must specify correct materials, use proper placement and curing procedures, and employ good drainage and moisture-control practices.

Continued...