Three Forces That Cause Crawl Spaces To Fail

Wednesday, February 1st, 2012 by Jacques Bouchard

What's Damaging Your Crawl Space – And How To Prevent The Issue

Structurally speaking, there is no good reason to have a crawl space.  They're not as useful as a basement, and not as structurally reliable as a concrete slab foundation.  Additionally, they are a source of cold and drafty floors, unwanted pests, and potential air quality issues related to radon.

Simply put, there are only two good reasons to have a crawl space at all:

  • When properly sealed and insulated with closed-cell spray foam or rigid expanded polystyrene board, crawl space is easier to insulate than a slab foundation.  This makes sense if you live in colder northern climates
  • A crawl space provides a less expensive building option over a basement or concrete slab foundation.

In other words:  The primary reason to build a crawl space is to save money.

Because these structures are made with money saving in mind, they are often poorly designed, and are notorious locations for building flaws of all kinds.

A structurally damaged crawl space can mean a wide variety of issues upstairs, including uneven or “bouncy” floors, jamming doors, musty smells, exacerbated mold sensitivity issues, cracks in drywall, and much more.  Typically, these are caused by one of the following three issues:

1. Poorly Designed Structural Supports

Crawl spaces are often designed with too few supports to properly hold up the structure in the long-term.  With too much weight bearing down on them, floor joists and girders can begin to compress, crack, and show other signs of structural fatigue and failure.

It's also important to remember that the supports can only hold as much weight as the soils supporting them.  Unless each support has been placed on an excavated base of engineered fill (which is very rare), they're  liable to sink down into poor supporting soils underneath.

2.  Moisture, Rot, & Mold

Most homes still have the old-fashoned crawl space vent systems that are now being phased out of building code.  These vents have proven time and again to do more harm than good, bringing in outdoor humidity in the summer, moisture during wet weather, and cold in the winter.

As your crawl space becomes a damp, humid environment, it becomes ideal for microbial growth.  Mold and rot will begin to grow on all organic material in the space – including structural wood and components of fiberglass insulation.  This ruins the building materials and will result in structural damage as time progresses.

3.  Pest Damage

Crawl spaces provide many entrance points for pests, which can enter around window openings, through vents, up from the dirt floor, and through other gaps in the walls.  If those pests include wood-destroying insects such as carpenter ants, termites, or wood-boring beetles, your crawl space will deteriorate over the course of 5-10 years.

While regular pest inspections are always recommended, you can do your part to prevent these infestations by sealing the space and installing a vapor barrier on the walls and floors.  Many types of crawl space insulation do double duty as air sealing, providing with you the added bonus of increased comfort and energy savings in your home.

All content in this article provided by Southeast Foundation Repair – your experts in structural repairs and crawl space insulation in Lumberton, Jacksonville, Fayetteville, and surrounding areas in NC. To schedule a free, on-site inspection and quote, contact us today!

Southeast Foundation & Crawl Space Repair also serves the greater areas of Greenville, Kinston, Havelock, Raeford, Washington, Clinton, Dunn, Camp Lejeune & Newport NC.