Pier and Beam Foundation

Pier and Beam Foundation are also called as post and beam foundation, commonly used in the areas where water (flooding) is a potential hazard and soil have a significant clay content are likely to swell (when wet) and shrink (when dry).

As the name indicates, it comprised of:

Piers: It is concrete or masonry columns (footings) that start below the ground, extend upto the short distance above the ground surface.

Beams: It is the horizontal framing members that span between the piers, the beams support the floor joists and the plywood flooring is installed on top of the floor joists.

pier and beam foundation spacing

Introduction to Pier and Beam Foundation:

A pier and beam foundation consists of pedestals (piers), fixed in the ground with an average of 5 to 6 feet of wooden beams in the centre that support the floor joists.

These foundation typically have a slab on grade system for the garage, the piers may support wood posts that extend up to the beams.

In either case, the main floor of the house is wood-framed some distance above the soil called crawl space.

The crawl space allows easy access to utilities (especially when remodeling a bathroom), also enables a layer of air insulation between the floor and the ground.

However, the crawl space is a haven for the insects, rodents and occasional marsupial if they find a way to gain access.

Pier and beam foundation repair tips:

  • Maintain a proper drainage system.
  • Use a moisture maintenance system.
  • Check foundation damage regularly.
  • Also regularly inspect crawl space.
  • Examine gutters and downspouts.
  • Plant small shrubs.
  • Dig trench drains.

Pier and Beam Foundation Problems:

  • Decay or damage to wooden beams or joints.
  • Water-induced movement to inner piers and external piers.
  • Shim failure problem also occurs.
  • Also has minor construction problems.
  • It is crumbling concrete poles.
  • It causes the internal pier crack.

Pier and Beam Foundations vs Concrete Slab:

Pier and beam foundationConcrete slabs
A pier and beam foundation is rested on a stone located under the house & a concrete slab rested directly on the ground thats why concrete slabs are ideal for homes that are built on flat lots.Concrete slabs can be constructed very quickly, and they are cheaper than pier and beams foundations.

Advantages of pier and beam foundations:

  1. The extra bit of insulation from the air under the house.
  2. These foundations elevates the homes to protect them from floods and moisture.
  3. It provides crawl space between the house and the ground.

Disadvantages of pier and beam foundations:

  1. Slab on grade is a less expensive foundation however differential settlement may cause slab cracking.
  2. Slab on grade won’t allow unwanted guest to dwell below your feet, however slabs are usually more expensive when it comes time to remodel.
  3. It causes sagging, creaking and bouncy floors.
  4. Also has poor ventilation.
  5. It provide space for the Insects and rodents.




Pier and beam foundation are used to get more robust as they last longer, however, no foundation is resistant to soil transfer, i.e. owner should consider seeking professional help to detect possible signs of foundation issues.

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Hello, I'm Rahul Patil founder of Constructionor.com, I had studied B.E. Civil. This blog provides authentic information regarding civil structures, equipment, materials, tests & much more.

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