Building Tunnels, anyone?

[Ganoderma]

always wanted to have my own underground tunnel and room lol. anyway, i will build one when we buy our house :hihi:

 

 

one thing i keep wondering about is water....when it rains, how are floods avoided. i have experience doing house foundations, which often go under ground. we build the forms, pour the concrete and rip off the forms when ready. the black tar paint stuff is painted on and a plastic layer with one side of cloth is added. this is ok for houses which are not really far underground and rain tends to go away fast, but would this really work for a tunnel system? also foundations dont have this on the bottom, its jsut concrete on sand and rock layers so it has drainage....what happens if your in the situation of a no draining area...?

 

collapses of both tunnel and house above worried me is i figured making it more or less a triangular tunnel for strength and also fairly deep, say 3-4meters below surface. something else i worry about is the room situation, being a large open space 8 feet tall. obviously support beams are needed, but will get in the way of comfort.

[Moontanman]

A case in point might be the abandoned missile silos in the American Midwest, Deep under ground, many of them were bought and used as private dwellings. It would seem they were kept water free by sump pumps. After being abandoned for awhile they filled up with water and the new owners had to pump them back out to transform the silos into homes. So the key to building under ground might be sump pumps, possibly solar powered?

[Ganoderma]

bummer....i am wanting to avoid any water coming in in the first place....even if one does pump it out fast, its still going to be humid and feeling kinda fungi....

[Boerseun]

Well, you're planning to build something big that can hold water out...

 

 

...lemme think...

 

Yep - you're planning on building an underground boat!

 

So, whatever you'd do to keep a boat afloat, should work for your tunnel system.

 

For instance, you can do the structure with brick, and have your tunnels be arched brickwork, and then just paste the entire inside with fibreglass. Same as a cheap boat. And you have to apply only a thin layer of fibreglass, seeing as it won't be structural and won't take any stress. That's what the bricks on the outside is for.

 

I won't go the whole pump-system routine, because they might just break at some critical moment! Or you might be away for a weekend and come back to a flooded house!

 

But I'm interested - what's your interest in an underground room and tunnel system, in any case? I think it might be a good idea to buy a plot of land and build your house underground purely from an ecological point of view - have your yard return to nature, as nature wants it...

[Moontanman]

The underground bunkers seem to make quite good homes.

 

6 Shockingly Eccentric Converted Properties | Nubricks

 

Missile Silo Homes: Interesting Thing of the Day

 

Missile Base Silohome DVD and Information Package.

[Ganoderma]

the fiberglass thought crossed my mind when i was looking into tar type stuff....i am wondering though, is there any disadvantage to doing this on the inside? for some reason i am thinking it would be better on the outside (brick against dirt) rather then the inside....but i cant really say a good reason why i think that lol.

 

why? always wanted my own tunnel. when i was young i wanted to grow -plants-, then i grew up and paranoia made me think a bunker just in case....now i am married and baby on the way and i am thinking an entertainment room and "fun daddy space" away from everyone else :eek_big: no matter the reason the basic theme will be the same....needs to be secure/safe (and DRY :eek_big:) , have electricity and at least one open room say at lease 3x3 meters or equivalent.

 

I think it might be a good idea to buy a plot of land and build your house underground purely from an ecological point of view - have your yard return to nature, as nature wants it...

 

fantastic idea! that just may be in the cards. we are scoping out properties right now in canada. probably wont buy til this spring i would think. but i like to leave lots of time ahead to think.

[Ganoderma]

just saw a thing on the tube at a restaurant where they used fluorescent lights and rigged them with fiberptics to get 60% energy savings or some such thing. i am wondering perhaps setting up something like a magnifying glass, but big, on a really bright surface and then running fibreoptices down underground...glass tends to filter out a lot of UV and other radiation, so it makes me wonder what the light coming through is like (straight fibreoptics, without additional input) my thought is underground farming, and if its a possible thing in a sustainable way...

[Turtle]

... i am wondering perhaps setting up something like a magnifying glass, but big, on a really bright surface and then running fibreoptices down underground...glass tends to filter out a lot of UV and other radiation, so it makes me wonder what the light coming through is like (straight fibreoptics, without additional input) my thought is underground farming, and if its a possible thing in a sustainable way...

 

this is called a light-tube or light-pipe. :naughty: i think the amount of light-piping, i.e. size & number, needed for farming underground would be prohibitive. :confused: :evil:

 

Light tube - Wikipedia, the free encyclopedia

 

Light tubes or light pipes are used for transporting or distributing natural or artificial light. In their application to daylighting, they are also often called sun pipes, sun scopes, solar light pipes, or daylight pipes.

 

Generally speaking, a light pipe or light tube may refer to:

 

a tube or pipe for transport of light to another location, minimizing the loss of light;

a transparent tube or pipe for distribution of light over its length, either for equidistribution along the entire length (see also sulfur lamp) or for controlled light leakage.

Both have the purpose of lighting, for example in Architecture. ...

[lemit]

Now this really is boring, although I have to confess I've thought about it too. But there are enough parts of my house I never get to anyway. I don't need to create more. Still, the storage . . . .

 

Maybe boring can be interesting. I think radon might be a problem here. Does anybody know of an inexpensive, reliable way to test for radon?

 

Thanks. (Sorry for the pun.)

 

--lemit

[Turtle]

Now this really is boring, although I have to confess I've thought about it too. But there are enough parts of my house I never get to anyway. I don't need to create more. Still, the storage . . . .

 

Maybe boring can be interesting. I think radon might be a problem here. Does anybody know of an inexpensive, reliable way to test for radon?

 

Thanks. (Sorry for the pun.)

 

--lemit

 

with adequate ventilation, radon hazards can be mitigated. check local hardware stores for test kits, or here's a web source. The Radon Information Center

 

more than you care to know about radon: :hal_jackolantern: >> A Citizen's Guide to Radon | Radon | US EPA

[LaurieAG]

bummer....i am wanting to avoid any water coming in in the first place....even if one does pump it out fast, its still going to be humid and feeling kinda fungi....

 

A friend of mine once told me about 4 very large concrete water tanks that he helped build that were incorporated into the foundations of a house that was then built above the tanks. Ferro cement construction is cheap , lightweight, strong and watertight when finished correctly.

[JMJones0424]

Well, you're planning to build something big that can hold water out...

 

 

...lemme think...

 

Yep - you're planning on building an underground boat!

 

So, whatever you'd do to keep a boat afloat, should work for your tunnel system.

 

For instance, you can do the structure with brick, and have your tunnels be arched brickwork, and then just paste the entire inside with fibreglass. Same as a cheap boat. And you have to apply only a thin layer of fibreglass, seeing as it won't be structural and won't take any stress. That's what the bricks on the outside is for.

 

Underground structures have absolutely nothing in common with boats. The more appropriate analogy would be a submarine. If you were to follow Boerseun's advice, I can GUARANTEE absolute structural failure. You NEVER waterproof the inside of the structure, especially if you were planning to use brick, which is a very porous medium and mortar which would rapidly deteriorate underground anyway. Hydraulic pressures on the inner fiberglass shell would rapidly overload the fiberglass and cause failure, unless it was thick enough for it to be structural itself, and then there would be no need for the brick.

 

Ganoderma, it sounds like you have at least a passing knowledge of basement waterproofing, but the important part you left out, especially in slow draining soils, is adequate slope above ground so that rainfall will drain away from the structure rather than towards it. Extra insurance can be had if you were to use thick pond liner or some other extremely durable membrane and bury it 8 inches or so under the surface extending at least 20 feet beyond the dimensions of your cave, once again taking care to make sure slope ensures that rainfall drains away and does not pool over your cave. Imagine this being an umbrella for your cave. As long as you do not have a really high water table, this will absolutely negate the need for french drains and sump pumps.

 

A day or two of research on the internet can give you enough info to help you decide if you want to go through with this, but unless you have some experience in either engineering or construction, I would recommend having someone design this for you. Or perhaps convert some old fallout shelter plans to fit your needs if you can find anything like that. Waterproofing is easy compared to structural load from above and from the sides, and you certainly don't want to literally be digging your own grave.

 

Ferrocement is no different than regular cement when it comes to waterproofing (it isn't waterproof). Ferrocement is different from conventionally reinforced concrete in that it uses fine mesh wire like chicken wire rather than rebar. It is in no way whatsoever waterproof, and if you choose to go that route, then it should be waterproofed the same way as conventional concrete construction.

[Ganoderma]

never heard of Ferro cement...if its just mesh instead of rebar, is that really that structural? we used to build fake rock/waterfalls/landscapes in the zoo using very spread out rebar with mesh wired on with XXXXX brand cement and sand. we could walk on it and it was great for animals, but nothing i would trust with 20 feet of dirt and some water pushing in on it....for that i am a rebar guy...mesh seems more cosmetic, or am i missing the point here?

 

the thing i am having difficulty with is with say a foundation and concrete basement. usually the area directly around the walls is dug out and there is some walking room to apply tar and plastic (at least by BC, canadas current code)....with a tunnel, one only has access to the outside of the wall *before* the wall is built.....once the wall is built, there is no more access....unless there is a lot more digging involved...i am not thinking having a chunk of land and digging a big hole then filling it later when done, i am talking more about digging a tunnel through the ground underneath stuff. Vietnam style, but safer.

 

 

we buy our house this new year sometime, but tunnel construction wont start until everything else is all settled in (ie. insurance company is happy and not looking)

[JMJones0424]

Ferrocement, when compared to a same thickness of standard rebar reinforced concrete, is actually better. Remember, concrete is incredibly strong against compression, but incredibly weak against flexing. It is the steel that provides the rigidity against flexing. And in your application, we aren't just talking one layer of chicken wire, but rather many overlapping layers with concrete in between, somewhat resembling a cross section of plywood. It is most often used for free form flowing structures that can not be easily formed up, as it is far more labor intensive than standard rebar at say 6 or more inches thick.

 

I did not have in my minds eye a correct picture of what you want. What you need to look into is mining techniques and shot-crete, two subjects with which I am utterly unfamiliar with.

 

Waterproofing is still going to be the easiest part though, if done correctly. As long as the water table is below the maximum depth dug, and you prevent water infiltration from above by using correct grading and either waterproof membranes just under the surface or additives to truly waterproof the cement (I'm sure they exist, there are underwater tunnels lined in concrete).

 

However, I am of the un-educated opinion that it is far easier, cheaper, and SAFER, to dig a huge hole, build a structure, and then bury it, rather than to dig out a tunnel and line it. Whatever you do, talk to someone who actually knows what they are talking about first :)

[LaurieAG]

Hi Ganoderma,

 

never heard of Ferro cement...if its just mesh instead of rebar, is that really that structural?

 

More like 2-4 layers of chicken wire surrounding 2 inch mesh, a bit of reo and a soft steel tie on every intersection of the mesh in the entire boat/tank that ends up about 3/4-1 inch thick after plastering and finishing.

 

I've helped build 3 ferro cement boats, 18ft, 26ft and a 52ft trawler built under survey. We have a major seaway entrance near where I live. Wooden, steel and aluminium boats tend to break up very quickly in big surf, the ferro cement wrecks have to be dynamited because they don't break up in the same situations and become a real hazard.

 

Have you noticed how some concrete floor slabs are very shiny, slippery when wet and water pools on them while other ones seem to soak up any water that falls on them? When a cement surface is finished, i.e. smoothed multiple times with a steel trowel or mechanised trowling machine, as the main body of the cement starts to harden the trowelled edge becomes less porous as water and air voids are pushed out, creating a dense layer. If you finish concrete with a wooden float/trowel or broom, it will be very porus, soaks up heaps of water but will be a very non slip surface.

 

So correctly finished ferro cement is not only very strong, 1 thin external epoxy seal coat will make it extremely watertight and, as long as you don't use too many straight lines (round water tanks excepted), many different shapes and designs are possible.

[X-Man]

Ganoderma,

Hey what about using the large corrugated pipe thats used all the time by the roadway workers? If cost isnt to costly that is( probably is huh) You dig your hole put in the pipe and bury it,all done.Just a thought.

 

 

PS-Somewhere I seen 84" diameter pipe online.Room to stand.

[Yoron]

Concrete with steel fibers (thin ones, like 1.5 cm long 0.6 inches about) mixed in it will work, but you need to mix it well first so it stays mixed. As for the thickness? I think, depending on size maybe three centimeters up to five? Normally when you build a tunnel that is what you use, at least here in Sweden, but here you 'jet' it from the nozzle of a special type of concrete pump. And you use a concrete blend that dries almost immediately it hits the rock walls and the roof, as you want it to dry and stick as fast as possible, you will have to plan for that depending on how long time it will take you to put it up on the walls and roof. Then you can have dungeons and dragons to your hearts desire :) And you will depending on ?? need a good ventilation system. It helps with humidity too. I think there are 'warming coils' (special glass fibre tubes filled with warm water f.ex) you might bury in the cement too for your heating system, although I'm not sure on that, but I have a vague memory of it. But you can always build a false wall afterwards and put the coils behind that I guess, with some isolation to it, but make sure to leave place for air to circulate too.

 

And your wife finds it a good idea?

Or will it be yours inner sanctum perhaps :)

 

All of this is when constructing on rock. If you're going to build it under 'earth' like 'dirt' then you have to make it stable first, and that's a different construction type where you have to build forms first and then cast your concrete walls roofs etc. Quite complicated if you're not an accomplished carpenter and concrete man, and then you can use chicken wire instead to stabilize your construction, as suggested before.