Tornadoes are a very common phenomenon in the United States and almost every year thousands of people suffer its consequences. In such circumstances, building a tornado shelter does not seem like a strange thing to do and plan. More and more families are devoting time and resources to prepare a special shelter or a safe room to protect their family and themselves. It is a task that requires a lot of time, but it is worth it.
There are many things to consider before starting to build the shelter. In fact, you will have to spend the same time gathering material and information, and building the real shelter. The more time you devote to research and consultation with professionals, the better you will be prepared when the real building starts. We also recommend that you check the FEMA documentation on your website.
The y # 8216; Taking refuge from the storm ‘is a booklet you should know before you start building and gathering material. Not only that, but FEMA has established some strict regulations on the requirements to build a shelter. You can find these requirements again in the document mentioned above, the so-called FEMA 320.
Begin the preparation for the construction of the shelter.
The next most important thing, after reading the FEMA requirements, you must obtain a construction permit. The National Performance Criteria for tornado shelters have established some criteria that must be followed to ensure that the refuge offers total safety and protection.
This means that you will need this permit, including the advice of an architect or professional builder. They must inspect the area, the soil and the conditions to determine how the shelter can be constructed for optimal protection. In case you want to use the FEMA 320 guidelines, your plans must first be approved by the National Performance Criteria.
Continuing, you need to evaluate also the wind zone. This means that you have to determine the direction of the wind. There are usual currents and you have to determine from which direction the wind would come (and potentially a tornado). This will be a good guide on how resistant and reliable the shelter should be built. Therefore, you can check a wind zone map to determine these details. FEMA also provides useful information in this regard.
Then you have to determine and decide where to build the shelter. Should it be in the basement, inside the house, attached to the house or should it be a completely separate building in your yard? The decision you make may be based on your financial status or personal preference. Typically, tornado shelters built under the house may require a modification of the house and may be more expensive. If you want to build a shelter, without changing the construction of the house, this may be the most economical way.
Building a separate construction about 150 feet from the house (no more than 150 feet) can also be a more economical approach. The only problem is that you will be exposed to potentially strong winds, which can endanger your life, while trying to reach the outer shelter. An attachment to the home is also an excellent way to build a tornado shelter economically and economically.
To begin, you must first gather your material. You need metal frames, a lot of concrete to build the walls, the roof and the floor, and several tools for the real building.
Start with digging the hole first. You will have to dig a little more than initially planned, so that you have enough room to maneuver into the hole. Also, keep in mind that a tornado shelter does not have to be large (like a storm shelter), since tornadoes do not last long and you can spend about an hour inside, without access to the bathroom, kitchen, etc. Of course, building a tornado shelter means you have to prepare space for safety and emergency kits, including a first aid kit; They are mandatory in case someone is injured.
So, to measure the shelter, you can count 3 square feet per person. Judging from this, you can determine the size of the entire shelter. Count another square foot for the emergency kits and you will have the total size of the shelter. Use the FEMA documentation and design plans to determine how to use the given space in an optimal way.
Before you start building and laying the floor, you must first drill holes in the ground floor of your house. While preparing the floor and placing the floor of the concrete shelter, keep the bolts on the floor. Ideally, you must first make the anchors separately. Make them using a metal frame and pouring concrete into blocks to keep the anchors stable and solid. Then you can place the shelter floor. Otherwise, proceed to the placement of the floor.
You must use concrete for the floor and make it thick, at least 5 inches, so it stays firmly in place. If you are building the shelter immediately in contact with the ground, you must first level the ground before pouring the concrete. If you are building inside your house, you do not have to do that, since the floor is already flat. If the tornado shelter is designed as an external accessory to the home, you should also make sure to level the ground before continuing construction.
You are ready to pour the concrete. The amount must be calculated correctly according to the total size of the shelter and taking into account that the thickness should be approximately 5 inches. When you have done that, leave the ground and wait for it to dry. This may take up to a week.
During that time, it is advisable (but not crucial) to pour water on the drying concrete and keep it moist at all times. This will protect the concrete from cracking during the drying process and many professionals use this practice in their work. And since concrete is like a sponge, it absorbs a lot of water and moisture, so you’ll have to keep it moist almost all the time. Make sure that, if you are building inside your house, keep the room well ventilated so that mold does not accumulate. If that happens, wash it and repaint the walls or ceiling where it met.
Your next step is to prepare the walls (which are the bulk of your work). It should make them strong enough so that they can withstand winds of up to 250 mph (and even more). The walls must have a very resistant frame. Most tornado shelters have metal bars as a frame, because they can withstand incredible pressure. Fiberglass or wood board are also options, but the latter may be less durable, so you should plan well what material to use. It all depends on the area of wind you are in, so you should keep that in mind.
When the frame is ready and ready, it’s time to start organizing the concrete blocks and building the walls. You will need a percussion drill to make holes in each block of concrete, so that the frame you establish can pass through the blocks. This gives more stability to the whole construction. Start by placing the first layer of blocks. You will have to organize them in an intersection pattern, so that each of the two blocks stays one on top of the other. It is a pattern used regularly when structures, houses, etc. are built
When making the first layer of concrete blocks, pour the concrete into the holes in the blocks. By doing so, the new concrete will reinforce the bond between the frame and the blocks and make the base solid and virtually immovable. Again, keep in mind that if you do not want cracks in the new poured concrete, you’ll want to keep it moist and water it while it heals.
Continue to organize the next level of concrete bricks and repeat the process each time you finish a level. Determine the height of the entire shelter: you must be taller than the tallest member of your family. This means more than 7-8 feet. When you have reached this relative height, you will have to determine how to finish the edge. As you must cover the roof nicely and safely (which you will build later), you must build the edge separately. You will attach it later to the shelter.
Then, leave your material aside. You will again need concrete bricks, metal (or fiberglass) structure and concrete to pour. You need to thread the metal frame through all the bricks, so it will go perpendicular to the frame of your shelter. Drill holes through the bricks so you have the empty space of the bricks up (you may have to break some of the compartments of each brick to have a large empty space).
Do all this, so that it fits perfectly with the edge of your shelter. Place more metal bars in the holes so that they protrude from the bricks and are parallel to the frame of the walls. You’ll see why later.
When you’re finished with that, pour the concrete into the empty holes in the bricks and again soak the concrete with water while it heals.
Once this is done and the concrete ready, you should place this top edge over the shelter. Now it’s time to place the top edge that you just made on the edge of the shelter. Pass the metal bars of the walls through the top edge and you’re done. The metal bars that protrude from the edge must be bent so that later you can join and fuse more metal bars. Do it and perform this additional installation so that the metal bars cross each other like a chessboard.
When you finish this step, build a wooden frame around it and pass it around the roof. You will have to pour concrete on top to finish with the roof. Drill some holes in the wooden frame for ventilation. Since this is a refuge for tornadoes, you will not spend much time inside this shelter and ventilation is not a big concern. Of course, in case the door is blocked by debris and you can not leave the shelter after a tornado, you may have to stay inside until the rescue team finds it. Until then, you’ll have to stay inside.
Therefore, ventilation is important and do not forget to make sure that enough fresh air will enter. This is especially true if you have a large family: you can fill up inside very quickly, since you are building a very small and safe room.
Finally, you have to hold the door to the shelter. It has to be special and it can not be any kind of door. We recommend that you buy a special door exactly for your purposes. There are doors made specifically for tornado shelters and are tested and certified by FEMA. Before committing to a purchase, look for labels and stamps that certify these tests.
Usually, these special doors are sold directly with hinges, which are tested together with the same doors. FEMA advises you never to use other hinges for the doors you have approved, as they can not guarantee that these hinges provide sufficient safety and, in fact, can even cause injuries and endanger your safety.
This approach explained above can be applied similarly to a basement in your home. You can start laying foundations, anchors, walls and roof in the same way. You can also build the shelter inside the basement construction, but it may not be so economical. In any case, basements are much safer than the house itself, since it is built underground. That provides protection against the tornado, but not full coverage, since the wind can be so strong as to destroy the floor of the house and compromise its security in the basement.
So building a shelter room inside the basement may be the best idea, because it provides a second layer of protection. Typically, tornado shelters are manufactured (as explained above) using a large amount of heavy materials, and the total weight of the shelter can be almost enough to keep them firmly attached to the ground.
You can also get some advice from professional builders for these instructions and ask them to help you with your shelter. In this way, it will ensure that the construction will undoubtedly withstand strong wind pressure, falling and flying debris, etc.
Also, keep in mind that if you follow the instructions above and feel that you are not sure about some of the steps, or if you have to replace some materials with others, it is better to consult specialists and professionals. After all, the tornado shelter will be a safe protection only if all parts are installed and constructed correctly. If not, even an incorrect hinge can endanger the people inside.
Another advice is not to build windows, openings, etc., since they diminish the resistance of the construction. The only opening should be for the door. While the door is specifically tested for tornado conditions, it will be more or less safe inside the shelter.
Also, do not build a shelter below ground level if you are in a flooded area or near the coast, as the water can flood the basement and you will not be able to escape. If that is the case, build the shelter on the ground and keep the anchors built into the ground. You may have to make some modifications at home. If you are currently building your home and plan to add a tornado shelter, then do so while you are building the house; It is much less expensive and will give more strength to the construction and foundations of the house.
If your area is prone to storms and tornadoes, you may want to build a storm shelter, as it can be used for both storms (hurricanes) and tornadoes. If hurricanes are not a concern, you may want to build a very small shelter. You do not even have to be as tall as an adult person. Some people build shelters as small as bomb shelters, just so they can be safe during the tornado. After all this, they only last a short time and comfort is not exactly a priority.
If you decide to build such a small shelter, you can also save money and build an economic construction. Typically, the most economical shelter can cost you around $ 500. Larger shelters usually cost several thousand dollars. Building your own shelter can cost you for the materials (and the help and advice of some professional builders) for approximately $ 2000.
Of course, if you wish, you can buy a ready-made tornado shelter. These are sold at very affordable prices and can be attached to your existing home. They are fully equipped with a hinged door and some even come with emergency kits and first aid. Again, if you buy a prefabricated shelter, do not change any of its elements, they are used specifically to provide maximum security.