The Perfect Prepper House? (Part-3)
Guest article, by ‘NRP’…
After you have found your ideal lot/acreage/hector, you have your plans and permit. You’re going to be lying awake at night ready to start; not to worry about that sleep, after the first 3 days you will be sleeping like a rock, guaranteed :)
Laying out your house, take a little extra time and recheck all of your measurements and then recheck again. Once you dig and pour concrete finding a mistake can be costly or frustrating while you figure out how to change your home to fit.
Place stakes and pull strings, check for square and plumb. Make sure it’s “right on the nut”.
Take a LOT of time on the lot before laying it out, get the “feel” of the area, the winds the sun, how about the noise? Can you locate your home in a way it will reflect unwanted noise and line of sight (if you have neighbors)?
Digging and Over-ex
I ALWAYS over excavate and re-compact under foundations and slabs even if not recommended. I would suggest getting a “soils test” done to make sure you don’t have any nasty soils. Expansive Clays or over excessive Sands can cause HUGE problems.
The soils report will give you suggestions on what to do with any problems or hazards. Again I take the recommendations and “overdue it”, this is MY house; I want it to last a lifetime or 5.
When you do dig, make sure the excavator saves the top soil in a separate location, good for the Garden or Landscaping.
Let’s pour some Mud, AKA Concrete
Very first thing I will say; 4 FACTS about concrete, It’s HEAVY, It’s Gray (unless colored), It will turn hard, and It WILL crack (some).
Concrete is a mixture of 4 “basic” things, Rock (usually ¾” dia. ±.), Sand (clean or “washed”), Cement (a mixture of limestone and clay), and water. There are a LOT of “admixtures” you can add, like coloring, fiber, retarders (slows the cure time), accelerators (quickens the cure time).
Basic concrete “hardness” is rated in PSI or how many pounds per square inch of pressure the concrete can withstand before it breaks. The normal house building strength is about 3000 PSI (again I build MY homes with 4000#, Mr. Over-Due-It here).
There are some common variations to the “normal” concrete; Grout for example is basically concrete with very small rock, so it can be pumped into Block, the PSI rating is normally higher, around 4-5000 PSI.
Concrete does not “dry” it cures, it is a chemical reaction that hardens the cement when mixed with water. And yes the stories of concrete continuing to harden/cure for centuries are true. But 80% of the strength will be established in the first week (depending on many influences (like temp), 95% total hardness within a month.
Lastly, concrete is fantastic for compressive strength, very poor on tensile (pulling) strength, hence the need for Rebar (deformed reinforcing bar). There is a LOT of info on the web about concrete construction, if y-all want you could probably spend weeks/months reading, but Why? You already know the 4 basic items :) And did I mention it’s HEAVY!!???
My father told me 1000 times if he told me once. “If you start with a good foundation you will have a good building”. This is truer than 99% of the builders realize. How can you plumb and level a building if you have a sloping or out of level base?
Take your time setting forms and doing the “layout” it WILL pay off during the rest of the construction. Second I ALWAYS over build a foundation for my homes, if the codes say 16” wide and 8” thick, I pour 24” X 12”. Why? If the foundation cracks and separates, you have a HUGE problem.. Sorry, just a fact. I have seen homes literally break apart because of poorly or improperly installed foundations. Do it RIGHT. And don’t forget the Rebar :)
For you to “place” concrete (walls) you will need forms. These come in many different forms of forms, pun intended, but the two most common for “wall forms” are Symons style panels and “Ice Block”. The Symons Forms are set/placed using “ties” between the two outsides and are filled with Mud, afterwards removed and reused. “Ice Block” (many different names) is made from Styrofoam or a derivative, and is left in place after being filled with concrete. They also have the advantage of adding a good deal of insulation value, usually R-22 or more. Although they are quite, IMO, expensive, many feel they are well worth the added cost. Personally I feel a combination of the two are the way to go, I would not use Ice Block for an unheated area, root cellar, or Garage. But for a “safe-room area”, these puppies are ideal.
When building a basement/main-floor style home 99% of builders will use a wood structure floor between. If I was not going to worry about security (safe-room, SR) I would do the same, BUT in this house I will be placing a concrete floor, at the SR, between the “hidden basement” and the SR. Why? Because I want that “next level” of security when/if I evacuate the SR into the Basement. I will be placing an “escape hatch” in the floor to allow access to the Basement. Note, this will be a ½” thick Stainless Steel Hatch, very fire/torch and bullet resistant. Also I will be placing a concrete ceiling over the SR. If “they” are trying to burn you out, or a wildfire engulfs your home, this room will not burn. Secondly this will give you time to regress into the hidden basement or/and escape through a tunnel to a location a hundred feet away. This part of the House is all about that safety thing everyone worries about. FYI, I will be building the SR as the Master Bedroom/Master Bath/Laundry/Storage. Probably around 1000 SqFt. There will be a fire-proof door and window shutters also (later Info on these).
I also believe in a very very strong “structure” for the core of the building. Red-Iron as it is called is basically steel post and beams to support the loads imposed on a building, snow-loads, wind-loads, are the biggest culprit I build for, that and fire. The main house will be designed for very open areas, another reason for steel beams that can span longer areas without support in the span.
Most homes are built with “pre-engineered wooden trusses” these are wooden members that can also span distances, but again will burn and collapse. Note, please note that a “steel” building will collapse from excessive heat/fire, but the little extra time may be needed for several reasons. I know of several companies that build steel trusses and can assist in the fabrication of the steel supports. The “infill” between the columns will be steel studs, with “spray foam” insulation. FYI Spray Foam usually has an “R” rating 4-8 times normal fiberglass insulation, so a wall and ceiling can have R-values in the 50-70R value (think NO heat loss). Make dang sure you get the Electrical and Plumbing installed and inspected BEFORE you Spray Foam HAHAHA.
Next segment, Interior and Exterior finishes/coverings, Windows/Doors and “stuff”.
Again; thank you for your time.
Perfect Prepper House Part-1
Perfect Prepper House Part-2
Perfect Prepper House Part-3
Perfect Prepper House Part-4
Perfect Prepper House Part-5
These are fun to read and dream about. Thanks NRP.
One paragraph I missed to add to this
Ok, now we have a two story concrete box, a concrete swimming pool for a basement, and a steel erector set sitting on top. What’s next? Heck I don’t know, probably we need to look at “rough in” of the HVAC, Electrical, Plumbing, and a few misc. items. Interior and Exterior finishes/coverings, Windows/Doors and “stuff”. Ohhhh and don’t forget the roof. Going to be a lot to finish up in 2 more segments, but if it don’t snow inside our house, we should be good-to-go.
I think this is great. Something many don’t consider (or even know about) though is monolithic domes. A concrete dome, the concrete form/mold is basically a plastic bubble you inflate. Do the foundation. Secure the bubble, inflate, spay foam insulation, rebar pegs and rebar, then concrete. Leave bubble in place, acts as extra waterproofing layer. Bubble breaks down in sun though so paint a minimum, some (like I would) use heftier resource like concrete, stuco, or rock/stone. This offers protection to the insulation and your water/air right bubble. Domes hold its weight in outside walls so no inner load bearing walls or pillers, can really open up a floor plan. It holds other weights/pressures better as well, like snow, wind (which also mostly curves around), and even force of explosions and bullets if that’s a concern. It’s also super efficient. 1/2-1/4 energy to heat and cool. And because of the build style costs about same to build as wood frame home of same sq footage and furnishings. The difference saved in labor mostly as they are built in weeks, not months. Can build as big or as small as want and with one more stories. Studio apartments 16.5ft across, mega churches 280ft across and 70 ft tall. Water right and strong enough can bury entire home if wanted for ultimate privacy or nuclear radiation protection. I’d like to someday take thier two week class and build my own. The design process though makes so well insulated CO2 detectors might not be bad idea. Most houses drafty enough or use hvac enough get decent enough air exchange. These houses do not and people have got sick from CO2 building up without purposely ventilating. So the company reccomends all electric, but still have other options as long as do ventilate. (Gas having issue of increasing the CO2 build up) can be as simple as opening few Windows at night during summer or day during spring and fall. Capture that warm/cool air may help reduce energy use even more.
I think you mean carbon monoxide, CO, not CO2. CO comes from fuel burning appliances. Check the older articles on this site for Carbon Monoxide detectors. You have some good ideas. Back in the 60s they did ‘re-enforced concrete over mounds of dirt, then excavated dirt out after concrete cured.
Wow, I did not know that about the spray foam. Good to know for the future.
You want to be careful of the water content in the concrete. Concrete is at its maximum volume when it is poured. As it cures, it will shrink. That can lead to cracks and weaker concrete. You can tell the ready mix driver that you want a 4 to 5 inch slump. It will perch on your shovel. It won’t slop around but you save time and labor costs finishing the concrete.
Use vegetable fiber expansion joints between your basement floor and walls.
Concrete will dust for a while. So if you want to paint it, hold off for 6 months and avoid the paint flaking off.
You are exactly correct with the “slump” the actually test is a 12″ high cone shaped cylinder filled and slightly “bumped” to settle it, than the cone I removed, distance the concrete drops or slumps is the “slump”. In commercial I have seen the Specs going more and more for a 3″ slump, and less and less air entrainment. Harder to work, but a lot better PSI and finish. I see Residential still at a 4-5 inch slump.
Expansion joints, I like the “zip strip” plastic ones where you pull the top 1/2″ off and can use a good Butyl Rubber caulk to fill.
As far as painting concrete, make dang sure the contractor does not use any curing compounds. and to cover to retain moisture for at least 2-3 weeks.
Your touting of Red Iron for residential framing is probably not a realistic alternative. It seems attractive but lends a false sense of security. It must be properly insulated to resist fire collapse, and this is not practical in residential construction. Talk to experienced folks in your Fire Dept., see what they have to say. From a ‘building construction’ perspective, all kinds of problems arise when integrating with wood frame construction. Different rates of expansion, problematic attachment, etc.
Wood framing is much more cost effective. If you want fire resistance, investigate ‘heavy timber’ construction. Long flame impingement durability.
I respect your thinking, and would agree with the common wood-butcher contractor building a house. Personally I have integrated Concrete, Steel, Wood, and many other materials such as OSB, Stucco, Wood-sidings, and Metals with very few problems, it’s knowing exactly how to control expansions through expansion and “slip sheet” construction.
As far as steel being “collapse” resistant due to fire, I totally agree, steel construction and even concrete will collapse if exposed to fire over a long period of time. But as far as sustaining a fire, A steel framed roof with a fire encapsulated above the ceiling, will not burn, as a wood framed truss attic will. As will a craw-space under the floor. Fact is a wood framed house (floors, walls, roof) as compared to a steel framed house is more susceptible to a quicker and more extensive fire. Steel/Concrete do not add to the fire as wood does.
NRP I agree with the statement of having a concrete ceiling in your safe room and fire doors. Having read you re articles, have you located and begun to construct your future home.
Several relatives home in Canada spray foam on there concrete walls in there basement to retain a constant temperature. I haven’t seen this use in the US. Is foaming costly.
@ Uncle B
Actually I’m retiring in 2.5 years, so I am still looking for that hunk of land, But I am working on the plans and ideas for the house, 40+ years of experience is finally paying off. LOLOL I know what and how to build, So this next one will be a little more expensive to build, but well worth the cost in the long run.
Yes, Spray Foam is slightly expensive, but considering the cost savings in heating and cooling, I figure the payoff is about 6-8 years.
BE SURE to pull your layout strings tight enough! I did not and the center of my house is about an inch lower than the outside corners, and this small error shows up when installing siding, windows, etc. A little extra time is well spent in the layout phase…
OUCH!!!!…. good point when laying out, if you need to go buy an inexpensive Laser, or rent one for a week.
Question: Recently I watched a documentary on a special home build in West Virginia as well as speculation on who/why it was being built. Anyhow, the walls were concrete that had small pins added to the mix, can’t remember if the pins were steel or what. They said that the house could withstand anything ! Found that interesting. Question, have you heard of this mixture, and why would adding those pins make a difference in the strength of the concrete? Just curious. Thank you for the article : )
Maybe a concrete Faraday box? Interesting to contemplate.
There’s a huge home being built in the Missouri Ozarks that may be using the same technology you’re talking about. I’d include a link to an article, but with Ken gone, it may be a while before it gets the “green light” to be published. Just search for “Giant Home Being Built in the Hills South of Ozark” from the Springfield News-Leader, or you can probably just search for “Pensmore Castle.” It sounds to me like it might be being built by a person who prepares for the uncertain future.
@ Happy Prepper
I would like to see the Link, I’m sure Ken will add it later.
As far as “the house could withstand anything” ahhhh NO, don’t think so. It may withstand “almost” any weather related event, but “anything”, I will guarantee you if someone wants in, they can and will get in. There are not a lot of structures that can withstand a direct hit from a AH-64A/D Apache Attack Helicopter under full attack mood or a nice 5# charge of C-4.
As far as pins in concrete? The problem with that, concrete really does not “stick” to smooth steel very well, So adding mall pins to concrete? Maybe to help stop electronic signals? Don’t know. Seems like an engineer’s dream to me. Been doing this stuff for a very long time, and there is always something new to learn, so I will do a search. Maybe something interesting for sure.
I used a product called traffic patch that was cement with staples in it. there was a few kinds with various fibers also. It is meant to be used for high strength repairs to concrete, eg a warehouse floor that has heavy equipment carrying heavy loads. additives can be very very effective acting like a re-bar that strengthens the full volume. Also run a sprinkler on concrete once it sets up on hot days to slow the cure. Concrete that cures fast on a hot day will crack and have inconsistent weak points. If pouring in freezing weather you need to envelope the slab with tarps and use space heaters to get a proper cure (I built high rises in Canada) The curing is key to concrete strength. Also when pouring on a joint or patching use Xypex or a slurry bond coat with xypex and wet the dry concrete you are pouring on an hour before pouring this makes for a perfect bond with no cracks. The xypex will crystallize and prevent water intrusion on a joint good for below ground pouring. If you want to make a simple slurry bond coat to prep a patch use a few ounces of white elmers carpenters glue and cement and mix to a milkshake consistency and brush on your clean wet prepped patch area and you will always get a perfect joint/patch. An old man once told me “If you don’t finish high school what do you finish: concrete!” hahaha that being said there is science and skill to it.
Good info on some of the additives for Mud. I have used a lot of “Fiber Mesh” around area, and the Sticky Stuff mainly for repairs.
I will agree 100% that the old idea of just “pouring mud” is all that’s to it is a long gone fantasy.
My engineering side would say pins would distribute pressure better to prevent cracks and stabilize it much as straw does to adobe bricks.
Will be looking into this.
Just have not heard of this before. Are the pins steel? Would they not “rust” if on the surface and exposed to moisture? Is an interesting concept. Wondering if it would actually create a Faraday Cage? Hummmmm.
Just researched, and the episode was on The series “America Declassified,” I highly recommend the series-it’s on Amazon or Netflix. Episode is called Pensmore mansion. (Interesting note — According to that series, that entire area in West Va has alot of .gov activity. Look up Green Bank West Va – a strange test site by .gov with a small town with communication black out and the world’s biggest satellite. True or not, it is interesting and the house that is being built is bigger than the White House ! Thank you for all your input ! : )
Try this “link”
Travel channel dot com shows america declassified pensmore mansion
put this after the .com /shows/america-declassified/video/pensmore-mansion
NRP is so very correct in controlling the temperature and moisture of concrete as it cures.
A couple of easy ways….
Hot weather – when you can walk on the concrete, wet the entire surface and cover it with white plastic. Keep it wet for a week.
Cold weather – cover it with plastic and cover again with a layer of straw.
To keep the water in the concrete at a low amount, your supplier can add a PLASTICIZER to it. It’s very helpful in hot weather, but make sure you have enough help on hand to work the concrete and finish it quickly. Google it.
A word on slump. A concrete with a very low slump will not have enough water to properly hydrate the cement component. To high of slump, as in a wet sloppy mix will result in a weaker concrete and may be porous to water.
Certivex and System 90 are two products that are used on bridge decks in high salt areas. They are the best that I have found to date for sealing concrete. Cheaper alternatives exist.
Another hint: When doing a floor slab, say for your garage, use a 6″ thick slab with 6″ X 6″ welded wire embedded in over a 4″ bed of 3/4″ clean broken stone, compacting both the dirt grade and the stone with a vibratory plate compactor (you can rent one). As you pour, pick up the wire so that it is in the concrete. It does no good on the bottom of the slab. After a 28 day cure, feel free to park your truck on it
I agree on the raising of the mesh, we used to tie wire it to the tops of duplex form nails on a grid pattern to hold it up
Thank you for the article. Might be a good time to mention designing your plan to accommodate individuals who are wheel chair bound (or may become so in the future). Leaving at least 18″ between the door jamb and adjacent wall when door opens toward the user for example. If you have individuals who fit this, it is smart to check out handicap accessibility before you finish your design. Be a shame to build a home and not get around in it.
Good point about accessability. If you want a stairway between floors consider making it straight as stairs that turn are much more expensive to put lifts on.
@ j.r. guerra in s. tx.
Good point, I have build my last two homes and the next one as ADA compliant (mostly), additional items include No steps, 3 foot doors, “walk-in” shower, lowered ovens, gab bars in the bathrooms, lower windows, list is long, But take into consideration of getting older and ya just never know when you may be in a wheel chair or in need of these things. Make you home easy to live in. You ma even consider a one person “lift” for the basement.
We have used a well tested building system that covers both security, fire and energy issues ck Performance Building Systems out of Texas…an earth home system.
S Performance Building systems how to and lots of great pics.
@ The Rock
Thank you for the Link, I know there are a LOT of very nice systems out there and the technology is unbelievable anymore. I would suggest anyone do a LOT of research, and don’t get tied to one system alone.
Remembering this is “your” home, and you need to decide what and how you are to proceed. These articles are only to share what I have in mind, and how I will probably build my next “retirement” home.
I really do appreciate all of the input.
If you want to earthquake-proof a suspended slab used as say a roof in your dwelling use post-tension cables we used to lay them in a grid in the slabs in earthquake zones on highrises. It is a large diameter steel cable inside a hard sleeve packed with grease so they last forever. The idea is once the slabs are cured you torque the threaded cable ends to a few thousand foot pounds. Now your slab is “sprung” and has forces holding it together when it waves during a quake. Another good tip for building concrete in a soft area like farmland or sandy river delta you can drive piles down to the bedrock on a grid and pour your slab/foundation on that and it will never shift or sink (use the modern hollow steel piles)
Another great article NRP.
Concrete placement is crucial if you want a lasting job.Weather plays a role.Freeze /thaw cycle.Hot weather too. That’s why they pour concrete at midnight in las vegas so they have enough time to finish it.
Soil testing is the best advice people should follow from your article.Make or break a project.Dave mentioned driving piles to bedrock in soft soil areas.
We did that on Projects in North East Texas up by The Red River.There are a lot of houses up there with slab cracks due to the soil.
I suggest people save your articles.Great reference material.
Thanks for all the helpful and thought provoking hints . As we are in the planning stages of construction we appreciate the good points for discussion between us that comes from your article . We plan to build in the spring of 17 , Lord willing and the world isn’t too crazy yet . Thanks again and have a good day on thanksgiving .
Welcome, I have been trying to keep it fairly simple and not get to overly technical. Just tossing out ideas so to speak. I know there are a lot of good people on the Blog that will help and answer anything you have questions on. Or if you need help. Just ask.
Also, make your building experience “fun”, seriously. The best homes come from Families that realize this is actually a labor of love when building their own home.
Something that’s very very important in building your own home, when you get the framing done and before you start any finishes, I always find a Sage Brush and cut a limb, than fasten it to the highest place on the structure. It’s a old old tradition passed down through generations in my family. Supposable to ward off evil and all that kinda of stuff and to bring good luck to the family that lives there. I figure what the heck, it cant hurt hehehehe.
I have been a Structural Steel Detailer for 30 years if you ever need any technical “steel” advice. Doc
@ Doc Jackson
Thank you for the offer, appreciate that.