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crawlspace access outside First time home buyers may have heard the word “crawl space” but not had a good idea of what it refers to – especially if they have only lived in houses built on a slab foundation. So let’s touch on it today.

When homes are built on a raised foundation, rather than slab foundation, there’s space between the dirt under the house and the house itself – often 3′ (but not always), sometimes more.  Unless the structure is built on a hillside, there won’t be enough height to walk around in that space, hence the need to crawl in the crawl space.

Most of the time, access to this space is indoors and specifically on the floor of a closet, where there appears to be a flat opening of about 3′ by 3′, sometimes smaller.  This can make entry tight.  At other times. the access is via the outside (more likely the case in properties built before 1950 in Silicon Valley than in newer properties.)  Here it’s a lot easier for homeowners, inspectors and repair people to enter – but also easier for animals and pests.  Care must be taken, as with the vent screens, to keep unwanted visitors out!

Red flags in crawlspaceIf your home has a crawl space, you will want to monitor it. Plan either to enter it to check on things periodically or pay an inspector to do so as this is an area which can reveal problems like the presence of termites, water damage to the bathroom floors, damaged heat ducts, and more.  It is also important to periodically check to make sure that there are no intruders (rodents), standing water, or other issues such as cracked foundations.

Which is better – having a crawl space, or having a slab?


Slab vs raised foundation


Not sure if your San Jose area house is on a slab or raised foundation?  Here are a couple of hints:

  • If you have to walk up a step or two to enter the house, that points toward raised
  • If the front door is at the same level as the front walkway, that indicates a slab
  • Along the outside of the house, do you see vent screens along the bottom of the house?  If so, the foundation is a raised one
  • Does the interior of the house have heat registers on the floor? If so, the house enjoys a perimeter or raised foundation.
  • Does the inside of the home have hardwood flooring?  If so, it’s probably on a raised foundation as it’s challenging to put hardwood directly onto slab (you’re more likely to find something like Pergo rather than hardwood on a slab)

Further reading on foundations & crawl spaces

Cracked Foundations, Adobe Clay Soils and Water in Silicon Valley

Historic Homes, Willow Glen, Foundations and Red Flags

What Is Cellulose Debris (in a pest or termite report)?

Wikipedia article explaining what a crawl space is





  • Silicon Valley Realtor, selling homes in Los Gatos, Saratoga, San Jose, Silicon Valley, and nearby since 1993. Prolific blogger with a network of sites.