The Dungeon

Here is a tour of the “crawlspace” below our post-foundation house. Published here for the viewing pleasure of those with actual wisdom and experience with building. Thanks for taking a look!

First off there is an 8.5 minute video on YouTube of me working my way through the space. I’d recommend watching it first because the screen capture program I used to take the pictures below did so at a very low resolution. I didn’t realize that until after I was done. Sorry about that…

If you would like to see higher resolution pictures let me know and I will try to capture them, though it promises to be a bit of a pain. However the video has each still frame in a higher resolution that the pictures below, and perhaps that will be good enough?

Anytime I talk about “sheathing” or “fiberboard” I don’t actually know what I’m looking at or what it’s called. It has roughly the same makeup as peg board. Here are two pictures of me holding a piece in the daylight. Should I replace this stuff with the same stuff? Or should I try something different?

01-Fiberboard 1

02-Fiberboard 2








The floor/foundation is “wiggly” and this stuff is rigid, so I don’t think it’s a good match. Jacking the house, leveling it, pouring a new foundation and going from there is the ideal course, but there’s no way that’s happening this year. Could I use galvanized flashing?

Now that we know what I mean when I reference this stuff, let’s take a closer look at what’s going on under the place.

03-Toilet joists and block

Here is a look at what I call the “tank house.” Above the daylight is a connected outbuilding that houses the pressure tank for the well and the hot water tank. In the top- center of the picture you can see two floor joists rotted out and (completely?) buckled. I had heard from a neighbor that at some point in the past the toilet seal failed and filled the bathroom with a few inches of water for an unknown period of time while the previous owner was away. I’m guessing the concrete blocks were a make-shift support system for the failing floor. They are not level (like most of the floor above).

Here is a look at the toilet plumbing:

04-Toilet drain corrosion

05-Toilet seal







That seems to be a lot of corrosion to me, but it looks old and dry. In pic 4 you can see the “fiberboard” hanging down around the toilet sewer pipe. In pic 5 you can see the seal. It looks “oozy” to me, but it doesn’t appear to be leaking. Does this need some attention?

07-Bathroom floor joist bad

Here’s a closer look at the rotten/buckled floor joist by the toilet. Two look this bad. Can they be repaired? When should they be repaired? Do we need to jack up the house to repair them?

When the fiberboard sheathing fell, it came down almost like loading ramps onto the ground. I’m sure that invited mice into the place. The place has a history of mouse infestation, though it is currently clean AND I WANT TO KEEP IT THAT WAY. All the insulation in the floor bays is gone. We found quite a bit of it in the witches broom crown of the dead balsam fir that was in front of our place. So here is what the damaged floor joist bays look like:

06-Bathroom floor joist bay

That pretty much sums up the bathroom problems. So the remaining big questions:

  • Do I need to re-insulate before winter?
  • What do I use to replace the old sheathing to protect the new insulation (if present) and to seal up the floor from critters outside wanting to get in?
  • How much vertical room is required to put up the new sheathing? Some places have only a few inches of vertical clearance!

Okay, moving on. This is a typical shot of what belly-crawling through the space looks like. You can see the trench I had to excavate. There is about 10″ of clearance between the pipe and the trench floor:

08-Typical crawlspace manuevering

08-Typical crawlspace maneuvering

The fallen sheathing and missing insulation are a property of two spaces under the house. The rest of it (75-80% of the total floor space) is in tact and looks good. Here’s a typical example:

09-Good sheathing (typical)

09-Good sheathing (typical)

As me move from the bathroom under the kitchen, 50% of the sheathing and insulation in the kitchen seem to be in tact. Then as you cross the foundation beam that splits the kitchen floor midway, suddenly half the sheathing has fallen down and the insulation is gone:

10-Missing sheathing in kitchen (typical)

10-Missing sheathing in kitchen (typical)

Unlike the bathroom there is no evidence to my untrained eye that moisture has been an issue here. So what caused an entire section of sheathing to fall away? I’m wondering if one (or more) of the foundation posts shifted significantly at some point. When you cross into the kitchen section where the sheathing has mysteriously dropped, there is one post that doesn’t look perfect:

11-Central Post Shifted Maybe

11-Central Post Shifted Maybe

I apologize for the poor resolution, but the video shows this in much better detail. The post is not vertical and there are two concrete blocks are shoring up the foundation beam in the immediate vicinity. So the questions here are not unlike the bathroom questions:

  • Do I need to re-insulate before winter?
  • What do I use to replace the old sheathing to protect the new insulation (if present) and to seal up the floor from critters outside wanting to get in?
  • Can the post be repaired? When should it be repaired? Do we need to jack up the house to repair it?

The final big question is: short of jacking the house, is there any mechanized way to excavate/remove dirt and rocks rapidly from an enclosed crawlspace? Everything I’m doing is with a tiny utility shovel, a two gallon bucket and a small cardboard box all while belly crawling. If I need to get large amounts of material out in order to do any repairs, there’s no way I can do so using my current methods.

Lastly, not that there’s much in the way of questions here, but the front room or “sun room” on the north side of the house has no insulation over it, and none under it. And there is an awful lot of porcupine scat here. If I don’t have to do anything about it, that’s fine. But if you have suggestions about things I “should” do here I’m all ears:

12-Front room - no sheathing - proc crap

12-Front room – no sheathing – proc crap

Okay! That’s the tour of the lovely crawl space under my house. Please e-mail me with any thoughts or suggestions. Thanks for reading!