Tossing out an idea and looking for feedback

[woodrail]

Jamm, Just FYI, the drawing I posted can be easily modified to allow for vehicle traffic over it. In fact, as constructed, vehicles did travel across it. For long term, have a structural engineer look at it.

Plus, this system shown was designed to stop water intrusion from the roof.

 

[machine_punk]

I haven't stopped to read through all the other posts...but if I was going to do this, I'd make it dual purpose...

...like wine, make is wide enough to put wine bottle shelving on both sides.

...does your wife can food? make it it wide enough for 2x12 shelves on both side and use it as a root cellar.

...do you collect something? Build shelves or hang it on the walls in the tunnel.

Kev

 

[kbs2244]

I did some research on this a few years ago.
The precast oval culverts came out as the best way to go.

Dig a ditch and drop them in.
The dirt over the top was to be less than 18 inchs so the weight factor wasn't much.

I assumed a narrow foot floor to keep me out of any water seepage.

If you have precast experience it should be even easier.

 

[NUTTSGT]

If you stick with the tunnel idea, I have two questions about it.

If you seal it up like watertight, will you have to worry about it trying to "float" in a heavy rain period ?

If part of the tunnel is at or above the frostline, will it try to heave in the winter ?


Just asking.

 

[JamieK]

Heres the Bunker thread whick includes building a tunnel..

http://garagejournal.com/forum/showthread.php?t=12234

Have you decided on what you're going to name it? Tom, **** or Harry?

 

[Earlsfat]

...My retirement home doesn't mean that I'm old and fart a lot when I walk. ....

You should seriously consider the fresh air inlet deal. Hate to say it, but you will get older and probably fart when you walk. Cut a few loose going out to the garage means you'll have to walk back through them when you go back home, lol.

Seriously though... VERY cool idea and I'd do it if I were in your position.

 

[6768rogues]

I would use concrete or CMU walls with precast concrete planks as a top/ceiling. Our code would require a curb or equivalent construction around the garage end to keep heavier than air fumes from migrating to the tunnel.

 

[jamm]

If you stick with the tunnel idea, I have two questions about it.

If you seal it up like watertight, will you have to worry about it trying to "float" in a heavy rain period ?

If part of the tunnel is at or above the frostline, will it try to heave in the winter ?


Just asking.

1) The area where the house and garage will sit is on top of a fairly large flat topped hill. It has been perked and the result was quite good (don't remember the actual comments) so I'm not too worried about a watertight tunnel floating. It will likely have some type of channeled drainage system to move any water away. I've got a buddy who's a civil engineer looking into the various construction options along with pros and cons.

2) Heave will definitely be an issue with part of the tunnel being above the frost line. The narrower the tunnel the greater the chance of heave affecting it, which is one of the reasons I have eliminated using masonry block, even if they are fully grouted. You can combat frost heave in various ways, but my simple understanding is that the best method is to remove one of two things that create the issue. Water and cold. Since removing the cold temps at the frost line would be very cost prohibitive removing the ground water from the area (think drainage) to keep ice from forming is the most practical manner to fight heaving. IMHO anything other method just combats the result of frost heave.

 

[sberry]

A tunnel tall enough to stand it isn't going to heave.

 

[jamm]

A tunnel tall enough to stand it isn't going to heave.

In general terms, I agree with you.

The deeper the footing the better the chance of combating frost heave as the footing remains on unfrozen ground. That alone doesn't guarantee frost heave will not crack and damage walls as the soils expand due to freezing temps.

Water expands roughly 8% from liquid to a solid and not all the pressure created by the expansion goes towards the surface. Think about basement walls. Generally most cracking occurs in winter or after heavy rains due to lateral pressure being exerted on the walls.

I plan to funnel as much water away from the tunnel as I can before it gets a chance to freeze. Nothing is foolproof but I'm not going to discount the possibility of it happening.