Crawl Space Ventilation

[Joe Reilly]

Folks - I recently did an inspection on a hill side, where 1/2 of the foundation was poured slab and the other 1/2 was in a full walk-way entrance with a cripple wall...ok good, I didn't have to crawl...but my question becomes, this area had no ventilation with a dirt base, with exposed support beams, so my thought is that if an area has exposed dirt that can become moist that it should have proper ventilation. So my question becomes am I correct in my thinking or because the opening was so big (basically a full fledged storage area), is it not required ?

[Gunnar Alquist]

Folks - I recently did an inspection on a hill side, where 1/2 of the foundation was poured slab and the other 1/2 was in a full walk-way entrance with a cripple wall...ok good, I didn't have to crawl...but my question becomes, this area had no ventilation with a dirt base, with exposed support beams, so my thought is that if an area has exposed dirt that can become moist that it should have proper ventilation. So my question becomes am I correct in my thinking or because the opening was so big (basically a full fledged storage area), is it not required ?

Joe,

I am not sure I can picture what you are referring to. What is a "full walk-way entrance"? It seems to me that if this area was open to the exterior, you would not be asking about ventilation, so presumably there is a door?

Was this a partial, above-ground basement with a slab floor or is the living space on slab? Since you state "dirt base", it seems to me that half of the living space of the home is on slab.

I have seen dirt-floored basements in old homes that did not actually have screened vents and there were no moisture problems resulting. In general, ventilation is important, but the amount of moisture in the soil is a factor as well. Did you see any problems related to inadequate ventilation? How old is the home (approximately)?

[Jeff Zehnder]

I am not familiar with California but here in the "east" we would expect the underfloor space to be vented or closed & conditioned. There may be exceptions but generally i would report if i found the space closed but not conditioned and not vented. Depending on conditions i might recommend further evaluation but the moisture content and growth would be a concern.

Also, if this was a new build they may be attempting to keep out Covid-19!

[Marc M]

Folks - I recently did an inspection on a hill side, where 1/2 of the foundation was poured slab and the other 1/2 was in a full walk-way entrance with a cripple wall...ok good, I didn't have to crawl...but my question becomes, this area had no ventilation with a dirt base, with exposed support beams, so my thought is that if an area has exposed dirt that can become moist that it should have proper ventilation. So my question becomes am I correct in my thinking or because the opening was so big (basically a full fledged storage area), is it not required ?

Try the CRC, its free online.

[Marc M]

Folks - I recently did an inspection on a hill side, where 1/2 of the foundation was poured slab and the other 1/2 was in a full walk-way entrance with a cripple wall...ok good, I didn't have to crawl...but my question becomes, this area had no ventilation with a dirt base, with exposed support beams, so my thought is that if an area has exposed dirt that can become moist that it should have proper ventilation. So my question becomes am I correct in my thinking or because the opening was so big (basically a full fledged storage area), is it not required ?

Try the CRC, its free online.