Digging Out An Underground Workshop

[Michael] of Teaching Tech moved, and with a large crawlspace under the house, he decided to turn it into a workshop.

There were a few challenges that needed to be addressed first. He had to dig out the crawlspace to provide a level surface, though the depth was limited by the concrete footers the building stands on. The house is sitting on and around large amounts of limestone, which is excellent from a stability standpoint but causes problems for [Michael]. Water can easily travel through limestone, meaning it ends up in his newly dug-out crawlspace. He dug trenches for water to exit and laid down gravel. After a few attempts to level the floor, he found some recycled plastic floor mats and finally got them where he liked them.

Wheeling his tools down a long and steep hill to the shop looks like most of the challenge. But with a few additions to the shop, like hard tube dust extractions and a french cleat system, he has an incredibly functional dedicated shop space.

If your crawlspace is too small for people, a tiny remote-controlled forklift could turn it into the storage space you need.

31 thoughts on “Digging Out An Underground Workshop

      1. I don’t know what things are like where you are, but around here, you 100% need a permit, along with an engineering assessment, to dig out a crawlspace. Cave-ins are a real possibility with some soil types.

        1. Personally, as a building inspector, the best advice I can give on any changes to ones dwelling. Is to contact your local jurisdiction on whether or not a permit is required. Instead of just assuming one is not required and dealing with the consequences on the other side. Depending on the jurisdiction you are in, you could be opening yourself up to a citation or extra fees.

    1. Not sure where the guy in the video is from, but here in the US the building requirements vary by county and state, which means thousands of different requirements depending on location. In many rural parts of the country, there is no zoning and no permits. Build what you want. Don’t complain when it falls on your head.

      1. I don’t really have a lot of knowledge on these kinds of topics, but as far as I know, I would require a permit where I live for anything even remotely similar to what the guy did. I live in Finland, though, and we tend to have rather strict laws around such things — can’t even build a basic garage without a permit.

      2. “In many rural parts of the country,”

        Not many. It’s like less than 50 counties spread over a dozen states or something. The vast majority of the US has enforced building codes, although the more rural areas just get away with it most of the time.

        1. Many rural counties in the US with building codes still allow significant exemptions to those codes for work done by the owners or inhabitants of the property.

          Whether this is a good idea or not is a separate concern, of course.

          In any case, Michael lives somewhere Australia, so this is irrelevant.

          Australia has a national building code, but as a non-Aussie I have no idea whether it’s relevant or limiting or whether the various provinces can set their own restrictions.

          1. He sounds like he’s from NSW or VIC, one of the eastern states.

            This sort of thing would need a permit as a “significant internal renovation”. Some councils are too lazy to do a proper assessment though.

    1. Yeah ditto.

      I’d love to have a house like that, but I really do not understand his approach.

      Getting all the dirt out would have been so much easier with a conveyor belt (such as used for argicultural goods)

      And a simple concrete floor probably would have been cheaper then those weird plastic tiles.
      Painting the walls & floor could quite easily have kept the moisture out (but do put drainage under the floor).

      This looks like half a job done to me.

  1. Digging out the undisturbed soil near the footers has probably compromised the foundation. To do this properly, there should have been more footings dug and the bottom of the walls benched with concrete, and to support those, an overall concrete slab poured, not just some gravel and plastic duckboards. Also, there is no place for water to go, and it is just going to collect in that hole. There should have been weeping tiles laid in those trenches along the bottom of the walls leading to sump pit and pump to eject the water. Also, power tools standing on his perpetually damp floor. Really? He’s created a nightmare here, what you get when a handyman with the internet for reference tries to do a renovation.

  2. This is great! You could create an additional workspace without the government knowing anything. I for one refuse to grovel at the feet of them – seeking permits and paying for my freedom. I just surmise the situation, do it right, do it smart, and don’t involve anyone else. That is what freedom is.

      1. YMMV. i know a guy built a whole house without permits. county building inspector found out about it when he put in a new electric meter base. inspector came out, looked around, said the plumbing was totally unacceptable. he threw the whole book at them for graywater in the ravine, no zoning compliance, no permit, no licensed contractors, all together added up to a $75 fine. said as he left “i will not be coming out again to reinspect to see if you fixed the plumbing. send the check in the mail.”

        (if you’re reading that and thinking I got the wrong number of “not”s anywhere, you understand how surreal that was)

        otoh, one county over i know someone had to remove the illegal second story from her house!

        there is a fine art to knowing what you can get away with :)

  3. This has potential, but it will need some help. Source: it’s very similar to my cellar workshop.

    Step One is going to be getting some ventilation. “Heat Recovery Ventilation” is the Google Phrase That Pays. I like the two-concentric-pipes implementations, but the European-style rotating ceramic disk might be fine. Not sure how it will deal with the inevitable sawdust that gets into the air. Once you get the humidity down, “Boeshield T-9” spray on your tools will keep them from rusting and you only need to apply it every few months.

    Sump Pumps (plural) for the win, BTW. Almost anywhere will prohibit draining them into the sewer lines, though. Mine is grandfathered in as long as I never change it.

    And anyone else digging their own crawlspace expansion: Don’t dig into the roughly 45 degree cone of soil pressure below any part of your foundation or pilings. Your Secret Underground Workshop will be smaller than the house’s footprint, but the foundation won’t crumble after a few years of hard rains.

    As for permits and inspections: that varies wildly. The rule of thumb in my area used to be “as long as it doesn’t show from the street “, but now they hire a guy to walk around all the houses and look for non-tax-paid additions. Literally a guy walking, I’ve met him. No Google Earth for our county, no sir.

    Search a while and you’ll find the 10-20 year old real estate listing for a house where the owner dug a three level bomb shelter. Each level had a smaller footprint than the one above. Also, somehow Colin Furze is still alive, so there’s that.

    1. Just like NQ before, I also have some suspicions about exposing the foundation like that. I think it needs the back pressure of those (now removed) 50cm or soil to prevent the stuff from under the foundation from getting pushed to the sides. Especially during very wet conditions when the soil is saturated with wetness.

      Least would be some kind of measuring system (drive a vertical metal pole (or two) in the GND?) so you can at least measure it if your house starts sinking.

Leave a Reply

Please be kind and respectful to help make the comments section excellent. (Comment Policy)

This site uses Akismet to reduce spam. Learn how your comment data is processed.