FOUNDATION

Concrete

This section applies to standard steel troweled or light broom finishes. Specialty finishes are not included. Settling or heaving of soils under concrete caused by alteration of grades by owner or owner's agent, which create excessive ponding or moisture adjacent to concrete foundations, walks, drives, slabs, or patios, should not be considered the contractor's responsibility providing the contractor has met all the conditions called for in the contract, plans, specifications, and all code requirements. The contractor should be responsible to correct or ensure correction of settling or heaving if compaction is not according to the licensed soils engineer's report or if no alterations have been made by owner or owner's agent. All concrete should be placed in compliance with applicable codes and standards. This will apply to design strengths, testing, dimensions, frost lines, and reinforcement along with items not specifically contained in the codes, such as proper placement in a good and workmanlike manner to achieve appearance and function of the finished product.

Concrete - Efflorescence

The potential for efflorescence exists in all portland cement-based products. Efflorescence is a salt that is left on the surface of concrete upon drying and is generally of only cosmetic concern in nature. It often dissipates with contact with water or the passage of time. Efflorescence that is severe, recurring, or accompanied by degradation of the concrete surface may indicate the application of excessive moisture, an elevated concentration of salts in the applied water, numerous cycles of wetting and drying and/or a more substantial presence of salts within the surrounding environment.

Natural Concrete - Color And Shade Variations

Color and shade variations are inherent in all portland cement-based products. These variations may occur and are generally acceptable. These differences can be attributed to a wide variety of causes. Some causes include variable jobsite conditions and changes in aggregate source, age, degree of curing, and specified slab substrate.

Post-Tension

Cracking in a post-tensioned slab is normal, and often post-tensioned slabs exhibit fewer cracks in number, but hairline cracks are not uncommon. The purpose of the steel cable is to improve the structural performance of the slab and foundation system, per the structural engineer's design, often to improve performance on expansive or weaker soils. The post-tensioned slab and foundation system is designed to act as an integral unit, distributing its own weight and the loads it carries uniformly into the supporting soils.

Concrete - Freeze (Or Frost) Lines Zone 2 + 3

In areas above 3000 ft. elevation concrete should be air entrained according to A.C.I. specifications for the aggregate size of the concrete being placed. It is recommended that denser concrete be placed to offset the effects of freeze and thaw along with placing the concrete below the freeze line. The freeze line will vary with the elevation. Recommended depths are as follows:
Elevation 3000-4999 Ft. 18"
Elevation 5000-6999 Ft. 24"
Elevation 7000-8000 Ft. 36"
Check with local building officials for required depth in the area where the construction is planned.

1. PD Cracks in "cast in place" concrete stems.

AT Cracks wider than 1/8" should be properly repaired with appropriate material. Cracks over 1/4" indicate the possibility of settlement, heaving or other failure.

CR Contractor should properly fill cracks with appropriate materials over 1/8" but less than 1/4". If cracks are 1/4" or wider, contractor should determine the cause and make proper repairs. Repairs should be made near the end of first year to allow the building to stabilize.

2. PD Cracks in basement floors.

AT Cracks in excess of 3/32" width or 1/8" vertical displacement or compound cracks in excess of 1/16" in width are not acceptable.

CR If vertical displacement in excess of 1/8" or compound cracking in excess of 1/16" in width is present, affected area should be replaced.

3. PD Cracking of garage slabs, carports, exterior slabs, patios, driveways and sidewalks.

AT Cracks in excess of 3/32" width or 1/8" vertical displacement or compound cracks in excess of 1/16" in width are not acceptable. Cracks of 3/16" are acceptable for sidewalks.

CR If cracks in excess of 3/32" width are present (3/16" for sidewalks), or compound cracking is in excess of 1/16" in width, or vertical displacement exceeds 1/8", the affected areas are to be replaced.

4. PD Patio or carport slab cracking at columns.

AT Half moon cracking at column base is unacceptable.

CR Contractor should make necessary repairs.

5. PD Settling or heaving of stoops or steps.

AT Settlement or heaving more than 1/4" is unacceptable.

CR Contractor should make necessary repairs.

6. PD Spalling or pitting of concrete.

AT Concrete should not deteriorate to the extent that the aggregate is exposed or the aesthetics are destroyed under normal use and weather conditions.

CR Contractor should take corrective action necessary to repair or replace defective areas. Contractor should not be responsible for damage caused by chemicals applied by others.

7. PD Ponding or standing water on garages, patios, stoops, carports, walks and driveway concrete surfaces.

AT Water should drain. Standing water exceeding 3/32" is unacceptable. Standing water exceeding 3/16" on driveways is unacceptable. Flood, wait 30 minutes and then check for ponding.

CR Contractor should make necessary repairs.

8. PD Improper expansion and/or control joints in driveways.

AT Driveways should have expansion joints at carport or garage and at curb or sidewalk. Control joints at least 1/5 the thickness of the slab should be placed no more than 10' apart.

CR Contractor should correct to provide proper control or expansion joints.

9. PD Cracks in control joints.

AT Concrete should crack in control joints. Cracks exceeding 3/8" are excessive.

CR Contractor should make necessary repairs.

10. PD Uneven or wavy floors.

AT Floors should not vary from flat more than 1/4" over a 10' area provided the deviation is gradual. Deviations, dips, or sags over short distances and easily visible to the eye may be considered unacceptable.

CR Contractor should make necessary repairs.

11. PD Floors not level.

AT Floors should be level within 1/4" in any 12' run.

CR Contractor should make necessary repairs.

12. PD Corners chipped or broken during construction.

AT Chipped or broken corners in concrete may occur during construction. These chips and broken corners are unacceptable at move-in.

CR Contractor should make necessary repairs.

13. PD Different elevations between slabs.

AT Vertical displacement between two adjacent slabs should not be a trip hazard.

CR Contractor should make necessary repairs.

14. PD Excessive crazing of finished exterior concrete surfaces.

AT None.

CR Contractor should make necessary repairs.

15. PD Improper, inadequate, unsightly finishing.

AT None.

CR Contractor should make necessary repairs.

16. PD Frozen or frost bitten concrete.

AT None.

CR Contractor should make necessary repairs.

17. PD Pop-outs in concrete slabs.

AT Minor pop-outs are acceptable if repaired. Slabs with an excessive amount of pop-outs are unacceptable.

CR Contractor should make necessary repairs.

18. PD Post-tension cable design.

AT Review by designing structural engineer.

CR Follow the direction of the structural engineer.