Flood Damaged Home in Houston

P = ρgh

ρ = m/V = fluid density
g = acceleration of gravity

h = depth of fluid

Seems like a weird question, but I wouldn't buy a house in a flood plane if I could avoid it.

I have a better idea!

Just buy a used submarine and bury it in the ground so that the top sticks out. That way if it does flood you can raise the parascope and play captain Nemo.

http://www.projectboats.com/whiskeysub.html

I was going to say an empty oil tank. With the price of fuel they all can't have much in them.

The walls will be OK, because the windows and doors will fail first and the house will fill with water, equalizing the pressure.

I know you said not to count the windows, but that's the only way to make your question not be meaningless.

If you want to withstand the pressure of 6 feet of water, your best bet is to build a dike around your house, or move into a converted water tank.

I would not buy the house unless it had overwhelming positive qualities to outweigh the flood zone problem. Most banks will require flood insurance if the building is in the "100 year" zone. If you need to resell the house, being in a flood zone can make it much harder to sell.

Without doing the calculation, I'd say that no, the walls would not stand if the water is 6 feet above the slab level, depending upon internal supporting wall spacing. If the house were not sealed, they would, of course, have a much better chance of standing: I lived in NC for a while in a town where hundreds of houses were under 10 feet of water during a hurricane. Most remained standing.

If it is in the 1% now, where will it be in 5, 10 or 15 years time?

Do you still want to live there if your house suddenly is in a 50% area?

I wouldn't, beer cans are only protected from rust on the inside.

33 feet of water is only one additional atmosphere at 14.7 lbs. I wouldn't worry so much about the depth of the water but the force of flow against the structure and anything floating in the water. Besides, as stated above windows and doors are the weaker points for seepage or collapse.

GA

Exactly! But he's only questioning 6 Ft. of water. Besides the fact my answer was facetious. Doors and windows, unless specially made, would be his greatest concerns. Pressure elswhere would be the least of his problem. But what about air circulation when there is no water? What about the exchange rate. Close the doors, go to sleep, "wake-up"??? Standing water would probably lift the typical home off it's foundation being watertight. But moving water and the additional uplift from displaced water would wreck havoc. Just consider that 75 MPH winds cause quite a lot of pressure alone but the force is in one direction and distributed along the entire framework. Once that weakest link gives out (roof, eave, whatever) the rest is like match sticks. This would be acting along all fronts and looking for that weakest point. Being a diver I understand water pressure and atmospheres. With proper equalization you don't even notice it. It's the subtleties involved that need to be watched very carefully. Don't keep an eye on them and you can end up dead. The greatest pressure would be at the base not nearly as much on the surface of the water.

Hope he takes what everyone says into consideration.

I expected a bit harsher remarks with respect to my choice and intelligence. Yes, I read that FEMA disclaimer and that, for a 30 year loan you could have so many times flooding. I was asking about the walls them self, if they can withstand the STATIC pressure. I have that handbook with the formula for density and viscosity (sic!) but what I don't know is if a structure like a house, no windows, no gaps, only very well sealed facade, will collapse. The house that I am talking about is built on a cement slab. 2x4's are stretched along the perimeter and on them there are, spaced 16 inch, the vertical 8 ft studs, that are the frame. On top of them it is built the support for the roof and the roof itself. The whole structure is like a cube, with lateral faces covered with apparent bricks (about 2-1/2 thick). Will this structure collapse? (water rises at a rate of one inch every ten minutes, no debris or animals to kick the walls!).

Water exerts a pressure of approximately 0.4 PSI/Ft. of Elevation so at the average of 3 Ft. there would be 1.2 PSI acting against the wall.

If the wall was 30 Ft. long (360 In.) X 6 Ft. High (72") you would have 25,920 Sq.In. exposed to an average of 1.2 PSI so there would be a force of 31,104# pushing on the wall. If the wall can stand that much force you have it made unless the water gets deeper which increases the Area that the roughly 0.4 PSI water exerts for each foot of depth.

I think that you answered my fears (you don't like the place I've chosen but you still get 1GA). No way, for that house, to be protected by a thin film, cheap and easy to be set on the walls. Unless there were reinforcements behind the walls, at a certain distance from each, other.

Thank you guys and I will invite you, soon, to visit my new (floating) house. You will understand why taking risks.

Now, the reinforcement of the walls it requires some work but it can be done. Remember those above ground pools, that have for support only few 2x4's and the pool walls do not collapse. I thought that there will be a construction specialist who can give me some "concrete" data. But I am sure that with reinforcement on the corners and in the center of the wall, the structure, if sealed, will resist. As for the floating (it is somebody's else remark), shouldn't be a bit of water under the house to have the upwards "lift" as in Archimedes's law? Still the only force is exercised by the lateral pressure but we, already, have discussed the subject

Captain Indel

Ask people who have built underground cisterns what happens to them when a flood comes along, the jump out of the ground....as do coffins in graveyards!!!!

Many concrete boats have been made over the years, they float......your house will too.....or at least try too....

Ask people who have built underground cisterns what happens to them when a flood comes along, the jump out of the ground....as do coffins in graveyards!!!!

I tried but they were unavailable (from the same reason!). Nevertheless, in my last trip to New Orleans I have seen some nice establishments and I've got some ideas. Because is costly to try to rise the house to put it on the supporting pillars (you know, the slab weights a....tone) I will wait for the first serious flood. The house will float and I will be able to move some 100 ft to the place I would like it to be.

P.S. I still don't understand those people having, as a pet, a boa constrictor!

May depend on how big your neighbors car, tree or fuel tank is as it floats down stream and smacks up against it.

If and when you would expect a flood it would be best you left your doors open. Which would stabilize the pressure on both sides of the wall. If you think that the fancy paint is going to keep water out and protect the interior not going to happen. One place of ingress is your sanitary drains.

It would probably become buoyant and float off the foundation first...

It sounds like there must be something pretty special about that house and or property to make you want to risk life and property over. Could it be the price? That's reasonable on face if you're willing to do more than just put some fancy paint on it. One of the home makeover programs had a show about a place in New Orleans that had gotten completely washed away. They built a new modular home and put it 10 feet in the air on 12x12 timbers supported diagonally with 8x8s and set in 6 foot deep concrete which was slabbed over at ground level. I don't remember how much that cost but I'll bet if it wasn't for all the free labor and material it would have been cheaper to find higher ground.

Lots of good information and speculation in the posts, and I'm not going to be one to add to the debate about the sensibility of your choice.

Couple things you need to look at:

Sealing the outside (sealing the inside of the walls would be useless as the water soaking and wicking up the insulation would cause mold, rot and other problems with the basic structure and would require major reconstruction to repair).

• You could seal the brick to the pad with tar. The same way flat roofs are sealed. It would be relatively ugly and you would have to seal up to the maximum expected water height, or all the way to the roof. If it goes beyond the eaves, you have a submarine.
• You would have to move the ac to the roof and also seal the intake vents to the same level. Ventilation in the house is going to be an issue.
• Every other egress (water, sewer, natural gas piping) will have to be packed and reinforced.
• Sewage stack should have a valve installed that you can close off to prevent backflow that would turn your house from a flood resister to a giant toilet.
• Reinforcing the walls. I would take a look at the California building codes for the earthquake prevelent areas and check out some of the reinforcing they require. They may seem like overkill, but they are pretty simple, just more time consuming. They basically tie the entire structure together to prevent shifting and collapse. Mostly just a series of 1/4" metal brackets or plates that are lagbolted into the the main load bearing structures. You might want to take a look at building codes for hurricane areas too, but I have no experience with those.
• Check all your wiring as well, at least anything that penetrates the external wall (cable is a good example, as most technicians just drill straight through from the outside). If it's coming into the house low, then have it moved and plug the hole, if it is a prewire (done when the house was built, you'll find a conduit in your wireing closet or near where your power comes into the house.
• Also, as mentioned before, you will have to secure the structure to the slab. 4' of water will probably pick it up off the slab. It won't do the boat thing, shearing forces will tear the structure apart as different parts release at different times.

This will probably do quite a bit to protect against hurricanes too, even if you don't get hit directly, high winds can do a lot of damage.

All of that will come to naught if you're doors or windows fail. Then you will have all the normal flood damage and probably have to pump out a lot as you've made it into a bowl for holding water.

My only real point of wisdom here is REINFORCE EVERYTHING, structural and not. That means every beam and every stud. Brick is a facia, not a structural element, find out what's behind it and how it's supported.

I hope the expenses are worth the attempt. It might just be better to keep the irreplaceable stuff upstairs, and create a savings account for damages.

Just my two cents, but should get you thinking.

Hello indel

Unless your Family name is Noah, give up any ideas of living on a flood-plain.

You would discover major problems getting dwelling and contents insurance.

Unless your dwelling is raised on columns/piers/poles/posts above the final flood level, one day, maybe tomorrow, (who can know), the water will come, because it always finds its own level.

Even if you have your house on columns above the flood level, water-borne debris may break a column or two, leaving your house at a drunken angle, tilted towards the swelling lake/river water, and you may survive, after watching the house contents cascade into the flood.

AAaaaarrrrgggghhhh......splash.

Kind Regards....

Lets say that "Smart Guy" is CORIUM CHEMICALS Austrailia, because the Paint does exist. Corium99. The pigment is derived from the underwater plant Lignum vitae. I have sealed concrete water dams with this. The weight of this paint is approx 3 x heavier than a normal paint. Its properties are such that you can wash the brush out with water within 5mins of using but sould you fail to do this your brush will morph into a solid minutes later. Demo for this paint: Take tin can, knock holes into its base via nail then paint the can. Give it 10mins then fill the can with water and boil over an open flame, e.g. blowtorch,throw out water, quench in cold water, batter the can with a hammer, No fracturing, fill with water again and boil, No leaks. Amazing. Now go paint your home Indel.

Is this paint available in the USA?

I'd love to paint my house foundation with this stuff then I'd never have to worry about a leaky basement.

Now go paint your home Indel.

I hope you are not serious. Making a house truly waterproof to 6' up will make it a boat. If the house has a 1500 sq ft footprint, Then the buoyancy would be 576,000 lb. This force will act nearly in line with the toe nails at the base of the studs, easily lifting the house clear of the foundation. Immediately after, the house would no longer be an intact boat, and will sink, some distance away from the original foundation. Houses are simply not built to float.

I'd assumed that Indel was doing this as a thought experiment, rather than as a practical exercise. Waterproofing a house against a flood is a very poor idea, and would require that the house be built to the much higher structural requirements of a boat, and would require an entirely different anchoring system.

If Indel is interested in a houseboat, I'd recommend something more like this:

http://www.bayacht.com/aaa/Marina/InvestorMarina.htm

Build your house on a barge then when the flood does come the house floats. Make sure you have good solid anchor points. And your utilities connected like a house boat would.

I often wanted to buy a piece of land near a river. Then buy an old house boat and have it set in place and anchored for the inevitable flood.

The hydraulic pressure from 6 feet of water is 62.4 lb foot measured downward from the top. The critical equivalent force point (center of force) is 2/3 the distance downward from the top. The average force is 1/2 the depth of water x 62.4 . All the numbers are in pounds per square foot. My guess, is not only no, but hell no, the wall will not stand up to 6 feet of water and keep things dry. It will move the house and perhaps the foundation unless it's properly anchored. Dave R

Hello Indel,

My company exhibited at a mining/industrial tradeshow this past week. Here is an interesting product that was exhibited across the aisle from us that might be what you are looking for. I have no affiliation to this company.

http://www.liquidrubber.ca/

Suggest you plan for the flood. First pour a ferro-cement barge hull the size of the present foundation. Secure it to mooring posts with large anchor chain. Have a house mover put the house on its new foundation. Then, play Noah during the flood when it occurs, and invite your neighbors to come to your flood party.

ALL HANDS ABANDON HOUSE! BUILD AN ARK!

I don't live in the US and do not know the regular build of a house, so I cannot answer the question as set.

BUT a wall should be built to take vertical pressure of the weight of upper stories and roof - a normal wall is able, because walling materials usually have the same compressive strength along each axis, to accept horizontal force until the bricks are pulled apart; since bricklaying arranges for bricks to overlap on a vertical axis, they are much more difficult to pull apart when subjected to a vertical force. However a battering ram powered by a handful of men will take a normal wall apart because it will tear along the horizontal rows of bricks.

So, unless your thermic panels are load-bearing in three dimensions and their edges are at an angle to those of the brickwork you would need reinforcing bars set at an angle to the rows of bricks.

It must be possible to build a house to stand sideways pressure from 6 ft of flood water, but I assume that it would not require thermic panels because the thickness of the walls (at least three layers of bricks to avoid lines of weakness) would make them redundant

You might want to learn from the Outer Banks area in North Carolina. The area is beautiful. But is vulnerable to the hurricanes that blow in from the east. Build the house. When the area is devastated my an act of nature, FEMA comes in and grants money to rebuild to people that did not have insurance to cover them. Rebuild again better. Repeat whenever nature strikes. Prepare for the future. Buy prepaid airplane tickets. Take with you what can not be replaced. This may sound like BS, but it has been repeated whenever there is a disaster.

Indel , I send you this info "that comes from experience", "not from a classroom of" "GUESS-TOO-MATERS" who's only knowledge is derived from University Classrooms, and a few thousand $$$ of books, often outdated. I am a retired Building Contractor who has worked all over this nation, Including the Houston area.

Residential housing is designed to be constructed for certain strengths. Floods are not one of them, unless they are raised on pilings that stand above the estimated flood height.

You do not have to travel very far to see what happens to folks who's homes have been damaged by the flooding and moving water. Take a look at Galviston Island. There wasn't much left there when I visited there some years back when I was working in Texas. On the west end of the island you will find homes constructed on pilings. All of the new coastal development here in sunny Florida, that is here in western Fla. must be constructed so that the living area floor is above estimated flood conditions. 11 ft above existing sea level.

That doesn't solve your problem! Every one must live some where. You must determine the risks involved with your financial caps. Don't bother with sealing your home. It is built on a slab. Therefore it has designed in limitations, some already mentioned by classroom persons. Even your land value will diminish immediately after flooding. But will eventually recover. AS for your home, if the floods don't rise to high, the most serious damage will not be in view. You will have a sick building, requiring major repairs. when the wall coverings are removed, have knowledgeable several contractors provide advice regarding attaching the bottom plate to the slab and the studding to the plate. Likely, depending on the age of your home, it could have the plate held in place with only concrete nails. If all of the wall covering must be replaced, insist on strapping the rafters or trusses to the studs, not the top two plates.

Take the money you are considering on spending on water proofing your home and save it for costs not covered by Insurance. Choose your insurance co. carefully, as they are not all equal. But buy the best you can afford.

TMF

You get a GA from me for a really good post.

I hope that he hears you loud and clear!!!

If he ignores you and the rest, there is no hope for him anyway......sadly!

Thanks, It's nice to hear something kindly stated once in a while!

I've only been in the Const. Business for 42 years. Unfortunately when I graduated from HS my Dad couldn't afford college for me, and even though I worked an 8 hr shift after school in a ESSO service station for a year, as a junior, family crisis used that up. It was nice to have been accepted at seven different U's , including, Fla. St., Duke, Texas A&M, and others but I was not to get that opportunity. I got my education the hard way, I learned every thing I could from all that would teach me. One of the most important things I learned was "IT'S NOT WHAT YOU DO!!! IT'S WHAT YOU GET DONE THAT WILL KEEP YOU EMPLOYED, AND RESPECTED."

TMF

Absolutely true, but the Degree makes the door opening in the first place a little easier.....

You are very correct about the degree, Having a Daddy or relative in a good union has helped a lot of folks too. Unfortunately I had to find a way through the system on my own. Starting at the bottom makes you feel like you are carrying everyone else load too. It can be done. But many like me find themselves broken down physically from proving to the world that there is nothing that is going to stop them forever, and then you find there is a day of accounting coming when your abused body says, "NO MORE, DAMIT I CANT TAKE NO MORE. Life goes on however!

TMF

not enough information is provided - or known? what is the width and height of the largest flat surface (assuming a rectangular salt box footprint)? to determine if the walls would hold up, this info is needed along with info regarding the strength of the materials used (i can't tell you how well the brick will take pressure). picture this: a zero volume house would hold infinite pressure. the larger the walls, the larger the volume, and thus the less pressure (depth of water) it can withstand. if you are willing to invent miracle paint, and seal the house off to air and water, are you willing to modify the structure itself (perhaps with dome shaped walls)? your best bet would be a spherical home, with the image of a normal modern house painted on it.

Get real" the house already exists. About the most important thing that I as a Licensed Contractor needs to know is when the darn thing was constructed. I can then go to the building dept. and check the building code requirements for that time period. The brick on the building is nothing more than an exterior finish, attached to a wooden wall by straps. There may not even be plywood behind it. Many buildings built that way only had a single sheet of plywood each way on the outside corners. the rest of the wall was covered by an asphalt impregnated fiber board with no possible way of strengthening the the structure. If so the brick will go away in strong flood moving water.

No more information was needed to advise the requester as to where to put his money

I made a lot of money figuring out ways to correct the mistakes of engineers. If I can correct their mistakes, I must be an engineer by default.

TMF

• I made a lot of money figuring out ways to correct the mistakes of engineers. If I can correct their mistakes, I must be an engineer by default.

Don't degrade ourself so much. The difference between engineer and builder is the same as between fancy and practicality.

But sometimes known ways of doing things don't meet the requirements. And if we always kept doing things the "way we knew", we'd still be scavenging food and mates by clubbing whatever walked by. While the divorce rate was probably lower, the concussion rate was probably much higher.

I never intentionally insulted anyone this time. But the simple fact is that some great ideas proposed by engineers are just that, and are not economically viable. For instance look at the tables established regarding horizontal lumber loads. ex 2"x8"x10"can span 12' and carry a 20lb live load, spaced 16" on center if graded #1 or better. I can certify to you by experience that over a period of time the lumber will sag, and if it is supporting a flat or nearly flat roof, one day, when it is most troubling, brown spots will show in the ceiling. The 2"x8" joist/rafter should have been upgraded to a 2"x10" structual select grade.

TMF

I have seen this house, in a subdivision of Beaumont, TX some 12 miles from it. Set on a 2 acres, 4 bad, 4 bath, annexes and a very loud silence. I counted 22 big oaks, on the property. Only birds chirping. If curious, on whitepages.com, with search on address, type Thousand Oaks, Bevil Oaks TX 77713. Second house from the bayou.

I have checked with FEMA flood maps and the house is in the gray area. Then I grabbed a straw (while drowning in the flood) at the idea of having an ordinary plastic foil glued on the exterior of the house. The sealing would be helped by the pressure of the water on the walls. The only question remaining was if the walls would stand that kind of pressure. I even, in "desperation" played the devil's advocate (I almost wrote...bevil's) in order to get the right answer.

Well, all the comments were either on the subject or funny, and I gave my contribution of GA to the ones that I considered clarifying my thoughts.

I have made an offer for a house some 5 miles from this one, out of the FEMA flood zone, and the closing is scheduled for June 20th.

Thank you, guys, you were great.

WELL DONE Indel on your wise choice!

Several years before working in Houston, I was working for a construction company owned H.G. Nichols, I was there trying to decide whether or not I would accept their offer to become their General Superintendent. They were builders in Beaumont Texas. They build fine homes. Quality construction and all. If you get one of their homes I believe you will be happy. IF YOU REALLY WANT TO SEE SOMETHING EXTREME REGARDING HOUSES ON PILINGS GO EAST OF BEAUMONT TO BILLY BYOU AND TURN RIGHT. If they are still there you will see what some folks are willing to put up with just to live on a creek. AMAZING!

TMF