Discovered 440 square foot crawl under basement! Help!!

[Cheesesteak]

Hi,

I recently discovered our home has a sub grade crawl space under a portion of the house. This crawl is not vented and has high humidity, causing fungal growth. Is there a way to vent a sub grade crawl space? Typically, one would cut vents into the concrete foundation, however, no part of the crawl reaches above ground. Let me know what you think!

Options that have been presented to me so far:

Digging extremely deep window wells and adding vents.
Complete encapsulation of the space and adding a permanent dehumidifier.

What are your thoughts?

 

[Snoonyb]

Welcome.
What is the grade profile in relation to the floorjoist in that area?

 

[Cheesesteak]

Welcome.
What is the grade profile in relation to the floorjoist in that area?

I’d estimate about 2-3ft.

 

[Snoonyb]

I guess I should have clarified, exterior grade, because venting requires flow.

Were it I, and the exterior grade is lower than the floorjoist system, I'd cut in a couple foundation vents and a selectively controlled fan at the underfloor access.

 

[Cheesesteak]

I guess I should have clarified, exterior grade, because venting requires flow.

Were it I, and the exterior grade is lower than the floorjoist system, I'd cut in a couple foundation vents and a selectively controlled fan at the underfloor access.

This is a lovely idea! Unfortunately, it is about 6ft at least below the exterior grade.

 

[Snoonyb]

Thanks.
Are there other dwellings in that development, with essentially that same profile, and have you contacted them as to how they managed the issue?

Most, but not every, comfort heating system have a humidity setting, so another alternative would be to pipe both a supply and return air, to that area, which could address the dehumidifier.

 

[Cheesesteak]

Thanks.
Are there other dwellings in that development, with essentially that same profile, and have you contacted them as to how they managed the issue?

Most, but not every, comfort heating system have a humidity setting, so another alternative would be to pipe both a supply and return air, to that area, which could address the dehumidifier.

This is a great question. We just bought the house and it’s our first ever home. I’ve been walking around the neighborhood and I see houses that have vents! Ours is just on an extreme slope. Part of it is slab on grade, and the other is crawl. I could walk around and knock on people’s doors and see if any of them have a crawl space that is unvented and if they have addressed the issue.

So far every professional I have invited into the space has looked at it and expressed alarm, as it is SO not to code, even for the 70s when it was built. All of them tell me they can’t offer a solution for venting, which is largely why I’m so stressed out. I feel like we might have bought an unsellable house on accident.

 

[Snoonyb]

It can be enlightening.
If you had the house inspected, or If the seller had, had it inspected, there would have been a report which should have been disclosed to you, and should have noted the unvented area.

 

[Cheesesteak]

The inspector didn’t see it, and told us it was slab on grade. They are only liable for the cost of the inspection, so we are out of luck on that.

It can be enlightening.
If you had the house inspected, or If the seller had, had it inspected, there would have been a report which should have been disclosed to you, and should have noted the unvented area.

 

[Snoonyb]

Sorry to hear that.

However, inspectors, and the firms that are their employers, are state lic., so, were it I, I'd be filing complaints with anybody associated with them.

Some folks will waive professional ethics and integrity, for expediency, which will result in systemic corruption.

 

[Cheesesteak]

Sorry to hear that.

However, inspectors, and the firms that are their employers, are state lic., so, were it I, I'd be filing complaints with anybody associated with them.

Some folks will waive professional ethics and integrity, for expediency, which will result in systemic corruption.

Sorry to hear that.

However, inspectors, and the firms that are their employers, are state lic., so, were it I, I'd be filing complaints with anybody associated with them.

Some folks will waive professional ethics and integrity, for expediency, which will result in systemic corruption.

Well, the other issue, which should have been a red flag, is that we cannot say anything negative about them if we ask for our money back, which we did. Essentially, we are stuck with the issue and have to figure it out.

 

[Snoonyb]

Again, I sorry to hear that, and hopefully this, "discrepancy" will not, "up jumped the devil", when you market your property. Additionally, that, that, should expend you future negotiating skills.

The knowledge of what you discovered, had you been aware of, should be a value, when considering a remedy, regarding the expense, over time.

 

[Cheesesteak]

Again, I sorry to hear that, and hopefully this, "discrepancy" will not, "up jumped the devil", when you market your property. Additionally, that, that, should expend you future negotiating skills.

The knowledge of what you discovered, had you been aware of, should be a value, when considering a remedy, regarding the expense, over time.

Yeah! It absolutely sucks, but, I’m considering the full encapsulation route. I was quoted 16k to do it which is unfortunate but it does supposedly raise the value of the house and the company gives a 25 year warranty. Given that there is no way to vent it, I’m feeling like encapsulation might be the best choice.

 

[Snoonyb]

I see, so please read and understand that a warranty, in that it is only as good as the issuer, and that issuer, remains in business.

Is there an additional service agreement attached?

Understand the omissions, excluded & escape clauses.

Are they suppling the dehumidifier, and warranting that equip. for the term of that warranty, and if not, who, why, what and where?

 

[dsteinhorn]

What a horrible situation and potential health with the mold and fungus incubating there. We had a similar problem in Illinois where multiple additions were added to a small cottage with major humidity and house cricket proglems. It was a nightmare.

Since you have the floor open, access and coming up with a solution is easier than a finished floor with furniture on it.

I think everyone would agree that a closed, unvented crawlspace is totally unacceptable. It must be ventilated to keep humidity down or you will live in a moldy environment (bad for breathing human beings) and the floor joists will rot. If you are unable to put in window wells or joist level vents to provide access and ventilation, then a compromise solution will be to Insall ductwork work through the habitable space above to the outside to bring in fresh air from outside and vent to the outside to allow the creation of a crossflow with a blower system like they use to vent radon and keep the humidity down. Insulation under the floor will make this space unconditioned. I would not pull crawlspace air into a habitable space because it will likely stink no matter how well the ground is sealed.

I believe you can report the inspector without saying anything bad about her/him. For example, "we had a home inspection and the inspector erroneously noted the home was build on slab without recognizing the fact that it is half built on an unvented, subgrade crawlspace." That is fact and not "bad mouthing" the inspector.

 

[Ron Van]

Companies have been advertising encapsulation a lot around here. I didn’t know it was that expensive.

I might be wrong (because I haven’t researched it at all) but it doesn’t seem to be out of the DIY realm.

I guess the first thing would be to treat the mold/fungus, seal the walls and floor and then install a de-humidifier.

I’m not sure what they do for 16k. I feel most of the expense is because it is a nasty hard job working in most crawl spaces…I know because I have done a lot of work in our crawl space in the last three years.

If you are able bodied and willing, you could probably do it yourself for a fraction of the cost.

 

[dsteinhorn]

Crawl Space Encapsulation 101: A Beginners Guide (youtube.com)

Amazon lists many similar dehumidifiers. They pull ~500+ watts when running $500-1200. Much less than $16K if you install the encapsulation/vapor barrier.

Probably the best solution and looks like something an able-bodied DYIs could do as long as you have access to the crawlspace. I suspect you will want to leave a trapdoor for access to the space. When I put vapor barrier in my crawlspace in Virginia, there was a lot of condensation underneath the vapor barrier but much lower humidity in the crawlspace.

 

[Snoonyb]

Here is a thread from earlier this year, and there are others from earlier; Crawlspace concerns

 

[Cheesesteak]

Crawl Space Encapsulation 101: A Beginners Guide (youtube.com)

Amazon lists many similar dehumidifiers. They pull ~500+ watts when running $500-1200. Much less than $16K if you install the encapsulation/vapor barrier.

Probably the best solution and looks like something an able-bodied DYIs could do as long as you have access to the crawlspace. I suspect you will want to leave a trapdoor for access to the space. When I put vapor barrier in my crawlspace in Virginia, there was a lot of condensation underneath the vapor barrier but much lower humidity in the crawlspace.

I’m confused as they seem to think we need to have a place for the water the dehumidifier collects to go. So they are proposing we core through the foundation to make a drainage hole to the yard. Is there a way to install a dehumidifier without having to core through the foundation for a drainage area???

 

[Snoonyb]

Well, there is the alternative of periodically accessing the appliance and transporting the humidity, removed from the air, which accumulates in the dehumidifiers tank, in a liquid form, water, and transporting it to a receptor, like a sink, WC or your yard and then returning the container to the appliance, too again, be refilled.

You really need to come to a workable understanding of your selected remediation system.