Make a hole in crawl space

[Daniel1825]

Hello!

We have a crawl space of 110 sqm, and we've been working on fixing it up with plastic and a dehumidifier. However, there is a small area, maybe 2x4m, that is its own little space, with two inspection holes in the wall and two vents on the outside under the deck. I peeked in there and saw there was no plastic on the ground, just soil. As a result, the dehumidifier is working harder than it should, and the climate down there is more humid.

Is it safe to enlarge one of the inspection holes to get in?

Above it is our living room, single-story house.

 

[Daniel1825]

The blue line is approximately where that space goes.

 

[Daniel1825]

Looked through some drawings from 1975, and it seems like the small space has been extended there at some point.

 

[Jonatan79]

Wouldn't lose sleep over the missing plastic on that small part. Do you actually have a moisture problem or have you had a visit from a company that starts with A and ends with nticimex? :=)

 

[MsTake]

Wouldn't lose sleep over the missing plastic on that little part. Do you have an actual moisture problem or have you had a visit from a company that starts with A and ends with nticimex? :=)

Are you a bit anti Anticimex

 

[Daniel1825]

Wouldn't lose sleep over the missing plastic on that small part. Do you have any real moisture problem or have you had a visit from a company that starts with A and ends with nticimex? :=)

Nah, of course, but it bothers me since we've sealed the entire damn foundation and then discover there's an area that's not covered with plastic on the ground.

As I said, we have a dehumidifier; I don't want it to run more than necessary.

 

[Jonatan79]

Nooo of course, but it bothers me because we sealed the whole damn foundation, and then we discover there's a space that isn't covered with plastic on the ground.

as mentioned, we have a dehumidifier, don't want it to use more than necessary

Yes, but you didn't answer the question about moisture problems.

 

[Niklaspe]

Had a similar scenario, sealed the valves externally.
Inserted a dry air hose through one hole and left the other hole open as a return hole!

Also put a piece of tape in the T-joint for the hose! It's only 10 square meters that need to be dehumidified there - less flow! The same temperature and humidity as the rest of the foundation is maintained.

The dehumidifier targets the open part. Worked well.

Can upload a picture later.

 

[Daniel1825]

Had a similar scenario, sealed the valves externally.
Pulled a dry air duct (hose) through one hole and left the other hole open as a return hole!

Also put a piece of tape in the T-connector for the hose! It's just 10 sqm that needs to be dehumidified there - less flow! Keeps the same temperature and humidity as the rest of the foundation.

The dehumidifier is controlled towards the open part. Turned out well.

Can upload a picture later.

Yes, put some foam in the valves from the outside, the only issue is that the dehumidifier runs a bit extra since it also needs to dehumidify the ground in that space, but it's not the end of the world that such a small part is uncovered.. Might have to take it from above later when we tear up the floor..

Yeah, I might have to buy a T-connector and a meter of hose!

 

[Jonatan79]

Are you a bit anti Anticimex

A little when it comes to scaring rookie homeowners into buying expensive solutions! Often nothing needs to be done, and that's why I asked TS if there was a real moisture problem.

 

[Daniel1825]

A bit when it comes to scaring rookies into homeowners to buy expensive solutions! Often nothing needs to be done, and that's why I asked TS if there was a real moisture problem.

It's not Anticimex that convinced me of this, but it was installed when it felt damp, damp beams, and a slightly unusual smell, and since we have treated wood in the foundation, there is a risk it would smell. That's why we took the safe route, whether it's been damp for 50 years or if it occurred recently, we don't know.

If the subfloor is bad, we don't know since it's additionally insulated with Styrofoam underneath, and it will be an exciting surprise when we redo the floors.

 

[Niklaspe]

It is not anticimex that told me this, it was installed because it felt damp, damp beams, and a slightly unusual smell, and since we have treated wood in the foundation, there is a risk that it would smell. Therefore, we decided to be safe rather than sorry, we don't know if it has been damp for 50 years or if it has happened recently.

Whether the joist is bad, we don't know, since it is additionally insulated with foam plastic underneath, and it will be an exciting surprise when we redo the floors

If they have placed foam plastic boards then the crawl space is colder, - greater risk for mold. Have the same at my place but with a dehumidifier. Sleep safely + warmer floors.

 

[Niklaspe]

Yes, sprayed some foam in the valves from the outside, the only downside is that the dehumidifier will run a bit extra as it needs to dehumidify the ground in that space as well, but it's probably not a big deal since such a small part is uncovered.. Might tackle it from above when we tear up the floor later..

Yeah, maybe I should buy a t-connection and a meter of hose!

The dehumidifier is controlled from the main part of the foundation where you have plastic, etc. So it won't run any extra. The only thing you've done/will do is to run a hose into another space.

 

[Daniel1825]

The dehumidifier is controlled from your large part of the foundation where you have plastic, etc. So it won't run any extra. All you've done/will do is to run a hose into another space.

Exactly, it feels reassuring to have the gadget down there even though it costs..

I’ll get another coupling and hose so I can run it there too, thanks!

 

[Niklaspe]

Exactly, it feels reassuring to have the rascal down there even though it costs..

I'll get another coupling and hose so I can connect it there as well, thanks!

search for ventilation pipes at Biltema. They have 100mm pipes in different types that fit the dry air hose!