August 20, 2012

Here's Your Sign: Foundation Failure

This is more advanced tutorial on what to look for when determining whether or not your home has foundation failure. For an in-depth tutorial on what types of foundation cracks you should look for, read Foundation Inspection Procedures for Home Inspectors.

When conducting an inspection of your foundation, it's important to look for a variety of failure signs like bowed or leaning basement walls, bulging walls or extensive foundation cracking. 

When evaluating the foundation cracks take into account the severity to determine if it's an immediate foundation failure sign or an old settlement crack.

Minor foundation cracks:
  • Horizontal hairline – less than 1/16-inch.
  • Hairline concrete slab cracks that don’t extend into the foundation walls.
  • Hairline stair step or vertical cracks that don’t extend into the foundation footing.

Moderate foundation damage that requires monitoring or repair:
  • Old cracks with no sign of continuing movement.
  • Mortar cracks that are a result of damage caused by backfill being installed too early.
  • A horizontal bulge that is less than 1.5-inch and there’s no other sign of foundation cracking or damage. However repairing this problem early on will save you money in later repairs.

Severe foundation damage that requires a structural repair expert:
  • Sudden appearance of foundation cracking, especially in areas prone to sink holes.
  • Bowed walls or bulges greater than or equal to 1.5-inch.
  • Walls leaning or lateral dislocation greater than 1/4-inch.
  • When there are signs of recent or recurrent movement and settlement.
  • Cracks are wider than 3/8-inch.

Now take a look at the type and location of the crack to determine if the problem needs to be fixed immediately because there is a high risk of foundation failure. If any of the cracks match the criteria listed below, call in a foundation repair expert.
  • Broken bond courses
  • Bowed wall
  • Stair step cracks with broken bond courses
  • Cracks that are wider at the base of the crack with broken bond courses
  • Diagonal cracks that are located at the building corners or center of header
  • Horizontal wall cracks that are located low on the foundation wall.
  • Continuous crack that's wider at the top

To be used properly, this information needs to be combined with on-site observations at the structure which requires a foundation inspection. If you’re concerned about the building’s safety, stability or foundation condition please consult with a foundation inspection expert.

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