Replies

1. 
   frenchy | Apr 10, 2009 03:44pm | #1

   Concrete block is very weak.. grab a sledge hammer and you can quickly demolish it.. flying 2x4's etc. will do the same..

     I'd use poured walls  and do not skip on Rebar..

1. 
   JeffScott | Apr 10, 2009 06:26pm | #4

   I would do poured walls if I could afford a pumper. How would you pour it without using a pumper truck? I'd rather do poured, but when I get up 7 feet in the air I don't want to be hauling buckets.

1. 
   frenchy | Apr 10, 2009 06:56pm | #5

   Well you set your mixer above the place you want to pour.. Then it's all down hill work..

2. 
   Marson | Apr 10, 2009 03:54pm | #2

   Block would be plenty strong with rebar and core fill.

   However, as a carpenter and not a mason, I would consider a solid wood wall. Just solid studs, one nailed to the next. Given the price of a 2x4 lately (less than $2) it could be done for under 500 bucks. Just a thought. I've seen old boiler rooms constructed this way.

3. 
   GregGibson | Apr 10, 2009 06:21pm | #3

   Hmm, Jeff, 4 x 8 floor space is pretty tight for a shelter - hope you're not claustrophibic.  I mean, it would be great to have a secure room like this, extra special gun safe, and I guess in a tornado event, anythings better than the bathtub - but, grab your wife and turn off all the lights and go sit in the smallest closet in your house.  See how it feels, and imagine an hour or two like that.

   Greg

1. 
   JeffScott | Apr 10, 2009 08:41pm | #8

   Very true that it is a small space, but its all I can afford to spare. I should mention that the primary goal is to secure firearms and valuables. Secondary to that is it functioning as a tornado shelter. I guess I didn't really make that point clear, sorry if I didn't.So would anyone tie this off to existing framing or make it stand alone?

1. 
   Manzier | Apr 10, 2009 09:38pm | #9

   I'll preface that I am not a professional mason/contractor/builder/framer/etc

   In my mind, 4 in block isn't enough for a tornado shelter, and it shouldn't be tied to the existing frame walls.  The problem with tying to the walls would be any uplift caused by the roof coming off, and if those walls are tied to your roof framing, I think your block walls will be compromised.  If tornado protection is a goal, go with 8 inch with the processes described above, tying it into your floor, and not attaching to your walls.

   However, if you just want a safe, 4 inch should be fine and you can tie it to your framing.  That will make it tougher to breach from the outside by smashing through the walls.  It should also add support to the door side.

   Tracy

1. 
   JeffScott | Apr 10, 2009 09:51pm | #10

   Your advice is sound and along the way of my thinking. I will re-evaluate my priorities but I think that I want it more as a safe than as a shelter. Thanks!

1. 
   brownbagg | Apr 10, 2009 09:58pm | #11

   I have never seen a 4 inch block, except maybe landscape pavers or concrete chairs. a 4 inch is really a brick not a block. I though about safe room, I myself would use 12's filled with concrete with a concrete room about six inches thick

4. 
   gfretwell | Apr 10, 2009 07:14pm | #6

   4" block is not really structural and there is not much core to pour concrete in. "Stick and Dowel" about 4' or rebar into the slab (about every 4 of running wall, in each corner and both sides of the door frame) lay 8" block over these and use "U" block for the top course. Run another 2 rebar around the top and drop "hooks" down in the cores where you have the rebar coming up from the bottom so you have a 30" minimum lap. Knock small holes in the block so you can tie them.
   Then when you pour the top one or 2 courses (bond beam) and the dowelled cells solid you have a matrix that will hold that wall together.
   If you really want a solid shelter use header block on the top course (4" notch on one side), lay steel decking on it and pour the whole ceiling solid along with the cells.
   They have screen you put across the tops of cells you don't want to pour when you pour the bond beam.

5. 
   FatRoman | Apr 10, 2009 08:34pm | #7

   Have a look at the info from Texas Tech and their storm shelter research.

   http://www.wind.ttu.edu/Shelters/InResShelter.php

   The debris impact report might be of use as well to figure out the best material to use.

   http://www.wind.ttu.edu/Research/DebrisImpact/Reports/DIF_reports.pdf

   'Man who say it cannot be done should not interrupt man doing it' ~ Chinese proverb

   View Image

6. 
   rjw | Apr 10, 2009 10:18pm | #12

   More info on the web:

   http://www.fema.gov/plan/prevent/saferoom/faq.shtm
   http://www.fema.gov/plan/prevent/saferoom/fema320.shtm
   Plans can be dl'd from: http://www.fema.gov/library/viewRecord.do?id=1536

   ---

   "Ask not what the world needs. Ask what makes you come alive... then go do it. Because what the world needs is people who have come alive."

   Howard Thurman

1. 
   dude | Apr 10, 2009 10:44pm | #13

   you just described a holding cell with your sizing but without bars

   what you gonna do for light  , air , food  , 20 minutes max before insanity sets in .

   what valuables , jewllery , cash  get a floor safe & set it in the basement  or if no basement pour a block of concrete  heavy enough it cant be moved by two men

2. 
   JeffScott | Apr 11, 2009 02:51pm | #14

   Thanks rjw, I downloaded the fema doc and it does have some helpful information!

1. 
   dedubya | Apr 11, 2009 05:02pm | #15

   I am a mason, but I wouldn't use 4" block for T.S. or a V.S. , even core filling them you can pucnh a pretty good hole in them with a claw hammer with a few good swings, I would use cast in place concrete/ reienforced walls . Then tip them up on short dowels, Then dowel three sides. then drill and anchor then encloseing side. ---I least that is what I did for a feller who wanted a "imagination station" for him and his wife--complete with manacles...:).  

1. 
   sisyphus | Apr 11, 2009 10:42pm | #20

   " "imagination station" for him and his wife--complete with manacles..."

   Thats's funny! Potentially a whole new thread (ie. oddest customer request).

7. 
   Junkman001 | Apr 11, 2009 05:03pm | #16

   I would not tie to framing.  Including the door, you'll not do this for $500.  Tie to slab/floor/footing with rebar.  Get a book on masonry const, and be very meticulous about installing the door frame.  It's not that hard to learn to lay block if you have the inclination to take your time and do things right.

   Minimum 8" block.

    

   Mike

   Insert initially amusing but ultimately annoying catch phrase here.
1. 
   gfretwell | Apr 11, 2009 08:47pm | #18

   "It's not that hard to learn to lay block if you have the inclination to take your time and do things right."As long as you are not in a hurry ;-)
   The first trick you have to learn is getting the mortar the right consistency and that is no small trick. Then plan on wasting about a third to a half of it. Real masons throw that stuff around and make it stick on the edge of the block like magic. Your average duffer gets more down in the hole and on the floor than they get on the block. It is a skill I respect about as much as anything in the building business.
   You know a real mason by how fast he goes and how clean he stays.

1. 
   JeffScott | Apr 11, 2009 10:29pm | #19

   I consider a mason's job a form of art. I've watch a few in amazement. I have good background in tile setting, so I'm somewhat familiar with getting the consistency right with mortar albeit thinset mostly that I've worked with. If I go the block route it will all be minimum 8" core and rebar filled. I have a friend thats handy with a welder so we are going to make an over-engineered door of our own I think. I know my budget seems unrealistic but I'm trying to stay close to it.As far as casting walls, say on the floor then tipping them into place, what is the easiest way to tip them up? Just brute force or is there a trick I'm not aware of?Thanks for all your help and suggestions guys, you've given me a lot to ponder.Jeff

8. 
   Chucky | Apr 11, 2009 05:22pm | #17

   make sure that your door swings inside the shelter.  If you're in there and a tornado dumps debris in front of a door that swings out, you might be in for a long wait.