Code Book versus Common Sense

You are inspecting in a humid or mixed climate area and the house is 75 years old and on a crawl space.

Recent upgrades have been made and code officials have correctly (by the local code book) approved a central air conditioning system installation. You find the crawl space ventilated, as locally required, and with batt insulation attached to the flooring. The crawl space is dry and has a properly installed vapor barrier. This area was inspected as a part of the upgrade permit and approved, as well.

When you inspect the crawlspace of the home that was built in 1935, you find that the walls and floor joists are damp to the touch and the space smells exceptionally musty and “dank”. You are able to see that the paper side of the insulation that is touching the flooring, above, shows signs of moisture staining as well.

Do you advise your client to violate the code requirements for that area and seal the crawlspace to keep the humid air from entering and condensing on the (now cooler than designed to be in 1935) floor? Do you pass this off to some kind of “specialist”? Do you ignore the problem, since it is all done according to the local code?

What would you do?

I would recommend sealing the Crawl space and add a dehumidifier if they have Elevated moisture reading .

I agree.

Now, let’s move ahead about five years when the house is up for sale, again.

Home inspector, Norm Newby, has just passed his NHIE “one size fits all” test and with his new license and CodeCheck book, arrives to the now empty house to inspect it for a new buyer. (Not picking on new inspectors, here…but using this example as one most likely to be referring to a book to determine what to write in a report.)

He finds the (now) dry crawlspace to be unvented which violates the local code.

What should he do?

Is the air being conditioned in the crawlspace?

Nope. It’s being conditioned in the air above the crawlspace. There is a thermal boundary between the crawlspace and the space above it.

Does the thermal boundary breath?

All do to some extent — but this one is no more than any other 75 year old floor over a crawlspace.

Then the inspector needs to write up the mold that will be in the crawlspace.

Do you agree, Roy?

Will there be “mold” in the dry crawlspace?

No active mould if we keep the humidity below 50% .There is mould every where . No moisture no high humidity no active mould… Roy

Is the dehumidifier still working?
Is it a commercial model?
Does the crawlspace have the vapor barrier installed everywhere?
What is the wood moisture and what month of the year is it?
With all of the above info, the report would vary depending on the sum total.

Some basics on this subject:

Never close off a crawlspace without proper methods.
Technically the vapor barrier needs to be sealed/caulked and run up most of the height of the foundation and piers also. A dehumidiifer is not required but necessary when the vapor barrier is not installed to meet the entire closed crawlspace methods.

Retrofit closed crawlspaces are allowed to leave the insulation at the floor as opposed to the foundation walls. Just inspected one today (sealed not conditioned) and it was bone dry and nice.

The crawlspace will not be dry. Moisture will rise from the soil and condense on your thermal barrier and drip back down. In Missouri, the humidity in the crawlspace would be above 60% on the good days.

If this (the walls and floor joists are damp to the touch and the space smells exceptionally musty and “dank”. You are able to see that the paper side of the insulation that is touching the flooring, above, shows signs of moisture staining as well.) is no longer present, no other moisture related issues were found, he should report nothing.

Read the first post.

This is a home about 60~ years old 20 feet from the river 8 feet about the river .
No signs of Mould Moisture and not sealed from the ground . Not vented and not well sealed .
This is the only log Chinked Home I have done .

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Okay, I am going get pass your first three posts that in reality does not make sense.

I do not know of any code that allows unvented crawlspaces unless they are conditioned. So if the unvented crawlspace is not conditioned, I would make note of it.

I agree.

But won’t the second inspector’s code book tell him that the crawlspace should be vented? Would he not identify a code non-compliance as being a “material defect” and recommend compliance, thus re-opening the vents? He is not aware of the history.

I am not a code inspector .
If like this home it is dry and has been forever why would I even think of telling the person they need to Vent it .

… Roy If it is not broke why fix it…

Sometimes Common Sense prevails. :smiley:

Install a thermal barrier right under the floor and then check for moisture after a year.