We have an above ground storm shelter. 10x10, made of concrete block, filled with rebar and concrete, 7inch roof and 10inch floor. It is terribly hot in there in the summer. What can I do to it to make it cooler?
We have an above ground storm shelter. 10x10, made of concrete block, filled with rebar and concrete, 7inch roof and 10inch floor. It is terribly hot in there in the summer. What can I do to it to make it cooler?
nobs, I built an above ground storm shelter for my mom using 12 inch knock out blocks, 5/8 rebar on 8 inch centers in floor, and walls and two mats of the same in the 14-16 inch thick ceiling. I used prebent 2x2 corners to tie the floor to the walls, go around the corners, and tie the walls to the ceiling rebar. 100% grouted the walls. I built the storm shelter as an addition on the side of her garage which is accessible from the enclosed sun porch and the hoise without going outside in the weather.
Wen I poured the ceiling (pumped actually) I had formed three 5x5 inch vertical voids in the ceiling. Since the ceiling is 14 to 16 inches thick, wind tossed debris would have to be going vertical downward to gain entry. I will be puting deflectors above the vent holes to cure that as well. When I installed the FEMA approved safe room door, I set it about 2 inches above the slab floor. Expanded metal welded as a door extension allows air to enter but not missles. Cool air comes in off the garage floor and the warmer moist (when occupied by humans) stale air rises up and out the vents on top. I planned to add fans if needed but they are not needed. The garage roof was extended over the shelter and the outside walls were done in the same vinyl siding as the house. It gets warm during the hotest weather but is never stifling or too uncomfortable.
I have a deep cycle 100 A-H battery on a little maint charger to provide 12 volts for 12VDC fluorescent lighting, small VCR/TV combo etc. It would run a fan too with no problems if we had needed one. I don't know how long you stay in your shelter at a time but we rarely need to stay inside more than a standard length movie. Given the brief time frame maybe you could grab a bag of ice from the freezer and take it with you. A couple cubes in a damp rag to hold in your hand and pass across your forehead would make a tremendous difference as would an iced drink. I will be uting up a bent bar to hold a privacy curtain in one corner where a porta potty will be added. Sometimes 2 hrs is a...L..o..n..g..time.
If you are in or adjacent to the house maybe you could run an A/C duct out there. If your storm box is exposed to the sun then you need to build an outer wall and or roof spaced out from the inner (concrete) wall/ceiling with room for air circulaltion to cary the heat away roduced by the sunlight being absorbed by the outer covering. If you allow enough room you could put a half inch or so of rigid foam with foil backing in the gap between the cement and the outer wall. The foam goes against the concret with the shiny side out toward the air space to reject heat (IR) radiation. The convective currents will "wash" a lot of heat out of the cavity. Reducing the temp difference between the outer wall and the foam with convective currents is better than adding more insulation because it is cheaper and is the same as an increased R-value in cooling the interior.
Hosing down the structure can cool it a bit too.
Other considerations: do not put a wired phone in your shelter as it is a lightning hazard. If you use a wireless phone leave the base unit outside of the shelter as it too is a lightning hazard. Do not put conventional house wiring into the shelter...lightning hazard. If you go DC like I did, leave the battery outside and the float charger too. unplug the float charger on the way into the shelter so there is no lightning path into the shelter.
Lightning kills many more people every year in the US than tornados.
P.S. IF you tell us what part of the world you live in we might be able to focus on the problem better. It is unlikely that too many CBN denizens will hire private detectives to try to feret out your location so they can take shelter in your "sweat box."
[img]/forums/images/icons/smile.gif[/img] [img]/forums/images/icons/smile.gif[/img] Pat [img]/forums/images/icons/smile.gif[/img]
"I'm not from your planet, monkey boy!"
I live in SE Indiana. How much space between shelter roof and new roof?
'fess up, Nobs. This place is where you'll go if the Commies drop the big one, right? Remember: drop and cover!
Not to change the subject, but....
Do you guys mind sharing your experience with pouring the ceilings? I'm planning on building a small tractor barn with an even smaller cistern underneath. I'd like to have the top of the cistern be part of the poured slab, so some details from your construction techniques would be appreciated (forming, reinforcing, hatches, etc. -- whatever you're willing to share).
I've been a TBN member for quite a while and REALLY am thankful for communities like these!!!!
Regarding a cistern under a building. This is not unlike my basement under my living room. The most cost effective ceiling/floor is NOT a flat slab of uniform thickness. You didn't mention the dimensions or if you want a free span or intend any central columns for support.
Cast in place concrete beams with large rebar near their bottoms as part of a monolithic slab pour is more cost evveftive utilization of materials. My floor has monolithic beams extending 10 inches below the 4 inch slab. Each has two each number 8 50KSI or better rebars near the bottom. The 4 inch slab portion has a N-S anf E-W grid of smaller rebar. My largest span is about 24 ft.
[img]/forums/images/icons/smile.gif[/img] Pat [img]/forums/images/icons/smile.gif[/img]
"I'm not from your planet, monkey boy!"
Thanks for the response. I'm planning on a very small area--only a span of 6' x 13'. A 24' span seems like quite an undertaking (no pun intended). The monolithic beam sounds like a good idea. I've seen a corrugated metal of some type used for forming in office building construction, though I'm not sure how good of an idea that would be being so near water all the time. Perhaps a tight grid of rebar would suffice...
best to you
gun, A 6x13 span is a whole lot easier. I have poured my suspended back porch (10'6" in short dimension) as a 4 inch slab over 2x8 and 3x8 rectangular steel tubing. Depending on the static and live loads you anticipate a simple slab with a grid of rebar near the bottom could be all you need.
Everything is compromise and trade-off... You might not need more than 3 1/2 inches (formed with 2x4) for the required strength but the water gives rise to other considerations. The rebar needs to be closer to the bottom of the pour to give more strength (bolster concrete's poor tensile strength) and increase the stiffness of the slab B U T... to protect the rebar from premature deteriation due to dampness, it needs to be at least 2 inches from any surface of the slab especially the bottom in your case.) Alternatively you could use epoxy coated or otherwise waterproofed rebar.
[img]/forums/images/icons/smile.gif[/img] Pat [img]/forums/images/icons/smile.gif[/img]
"I'm not from your planet, monkey boy!"
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