Flood proofing house
Posted by analytic_potato@reddit | preppers | View on Reddit | 48 comments
I consider myself to be an amateur prepper and it came in handy. We recently went through Hurricane Helene and Milton — I made us evacuate and my hurricane prep bag did indeed think of everything we possibly would have needed had we actually lost power/water/sewer at the places we evacuated. Been a proud moment. However— this post is more about the house.
This is a house which had never ever flooded before since being built in the 50s… but the house took 24” of nasty storm surge in every single room, which… gross. We had to rip out 4 ft worth of walls, all the flooring that wasn’t tile, getting someone to check plumbing and electrical bc it’s all shot… and somehow we didn’t take that much damage from Milton so starting to think and dream about rebuilding. And I want to be insanely prepared for the next time. So what would you do to prep your home for a flood?
Please don’t suggest moving. We know that. We also know nobody is going to buy this house right now without us taking a significant losses
Things I have planned so far — EnduraFlood PVC boards instead of drywall for the bottom 36” of the house everywhere except maybe bathrooms and kitchen (Hardie board or mold resistant drywall?), restore the original terrazzo floors + epoxy floors in the spots where there’s just concrete now, using outdoor kitchen cabinets (HDPE material) in the kitchen and wherever else we can find hdpe stuff that doesn’t exactly look like it belongs outside, shelving will be wall mounted above the 36” as much as possible…
Any more ideas? Ideally yes we would like to raise the house but I’m waiting on quotes to see how possible that is. I know we’re going to hit the FEMA 50% rule and need to do it anyways, but our current contractor thinks they can be creative and get around it. I think I still want to raise the house either which way but it’s going to depend if it costs 30k or 300k….
Hairy_Afternoon_8033@reddit
If you get water in your house again it will not matter that you have PVC enduraflood boards you’re going to probably have to take them out to dry out the studs and insulation. Does that really save you anything?
analytic_potato@reddit (OP)
Yes — we don’t have to demo the walls or pay someone to demo them. We also don’t have to pay for it to be replaced ever again. Just pop out, remove insulation, dry off and hose down the boards, then put new insulation and pop them back in. Saves thousands.
Hairy_Afternoon_8033@reddit
Oh I did not realize they were that reusable
analytic_potato@reddit (OP)
Yep! You’re totally right otherwise, wouldn’t make sense. This doesn’t flood proof it. But it does save us a lot of time, energy and money should we flood again.
hollisterrox@reddit
Elevating the house is going to be a lot more effective that spot changes to materials in the home. If the flooding is 37" instead of 36", your house is trashed again anyway.
I'm assuming a wood-frame house here, as that is extremely common in Florida.
Your inspiration here should probably be Hunter's Point , a neighborhood built to be hurricane proof that appears to actually be hurricane-proof. The first floor of every house is concrete and largely resistant to short-term water exposure.
analytic_potato@reddit (OP)
We have a concrete block home and the foundation is slab on grade, which I’m told makes the house very hard / expensive to lift but I still want to try. I’m thinking makes more sense to raise the walls and then pour a higher floor or something but I’m not sure. Trying to get quotes.
Thank you, I will look at what Hunter’s Point did.
hollisterrox@reddit
Okay, that's interesting , it won't be cheap but I suspect it would be worthwhile to talk to a general contractor or building engineer about dropping a steel frame into your existing home and building 2nd/3rd floors on top of that frame to be the majority of your living space, and use the original ground floor for storage and non-critical items. Don't put any finishing materials down there at all and they can't get ruined. Move electrical service and plumbing vents up a floor as well.
Jacking a whole slab up and supporting it is going to be, I think, insanely expensive/less feasible than just building up from the existing slab. Like, seriously, it's possible to be cheaper to deconstruct your home, store everything, live in a trailer for a year, and build a whole new home ground-up than it is to safely jack up and support your existing home. The jacking up isn't the hard part, it's the building a new , safe support structure under an original slab-on-grade that's going to be nutty. But I'm just some idiot with a keyboard, you can get accurate information from a local soil engineer, general contractor, and/or building engineer.
You'll also need engineering to figure out what you can safely load on the existing slab, because standards have changed over time, and so have technologies. In some shitty 1950's Fl neighborhoods, your slab may just be 6-8" of concrete poured on the ground with a rebar chucked in. It may not tolerate any attempts at movement or too much additional weight.
Best of luck!
analytic_potato@reddit (OP)
I got a quote today that to lift it onto stilts would be 245k and to build anything new would be somewhere around 300k…. I’ll see what the other places say but sigh. Seems out of reach.
hollisterrox@reddit
Yeah, that seems like a pretty good price actually.
Maybe pursue the steel frame idea. California buildings do seismic retrofits where they bolt steel members onto their buildings to shore them up, surely it can be done on a smaller scale for your house to give you a platform at the top of your existing walls to build upon. Then you’re just building a house , but 9 feet off the ground.
Eh, still going to be 300k.
I think you’re back to inflatable dams to prep for the next flood and hope it’s not too high.
account_not_valid@reddit
I wouldn't even build onto the existing slab. I like your idea of making the existing ground floor storage/garage etc. I'd then put pilings on the boundaries, outside the existing slab. Build the new living quarters above the ground floor, completely independent. Essentially, float a new house over the old one.
But. Probably still cheaper to demolish the old house and build new.
hollisterrox@reddit
You could also saw holes through the slab and drive/pour pilings within the footprint of the slab I suppose.
Kementarii@reddit
Rather than lift the existing, you could do something like has been done in my area of Australia. This is retrofitted.
The ground floor/1st floor is built brick/concrete block on slab, but is used as more of a basement - it has garage, laundry, rumpus/entertaining room, maybe a guest bedroom/bathroom.
This flood-prone area will have tiles/concrete flooring, plain painted block walls. Very simply decorated, and can be hosed out if/when needed with little damage. Maybe even keep the electrics up high-ish.
Upstairs is the main house all on one level (bedrooms, kitchen, bathrooms, living rooms), and is timber frame, drywall, and cladding. It may seem odd, but you do get better views, and better breezes up higher.
anony-mousey2020@reddit
Can you build up then, and just have your first floor as garage/utility? Essentially, wouldn’t that end up being the same?
anonking1181@reddit
I’m in the same position house and location wise. I’m in the process of putting a 1/2 HP sump pump outside next to all four corners of the house.
Sad-Consequence8952@reddit
Surround most of the house, well out into your yard with a retaining wall with large rip rap on the exterior and backfilled with dirt. On the portion you leave open for a driveway have a system in place to close it off with sandbags, portable dams, or a combo of both. The retaining wall system will need to be robust and expensive and you may need to buy several pumps to pump water back over your wall while you mend minor breaches.
analytic_potato@reddit (OP)
Does this work in a neighborhood?
Sad-Consequence8952@reddit
Depends on your neighborhood. If you have a HOA then probably not. Also depends on size of your yard.
NoEquipment1834@reddit
Did you have flood insurance? If so depending on damage amount you may qualify for extra payment ($30k) to lift house. Definitely best plan.
Did with my home after a storm. No worries for me any more. Would need 15 ft above high tide to get into living space of house now. Not impossible but not very likely where I am.
analytic_potato@reddit (OP)
We do have flood insurance. I’m trying to get a quote on how much it would cost to lift the house — if it’s $30k, possible. Even up to 50k or so, possible. But if it’s 100k or 200 or 400…. I don’t see how we can make that work.
NoEquipment1834@reddit
Cost is going to vary by area and your house and local codes as to how the new foundation is done.
analytic_potato@reddit (OP)
We got a quote today for 245k. Yikes.
Live-Put8179@reddit
Davie Shoring lifts houses in SW Florida, follow their facebook page. I’ve seen their posts that say it costs approx $100 per square foot. We thought about doing it after we flooded in Ian but our ICC coverage wouldn’t cover it as that was only $30k. We managed to stay at around 47% of value on our permit.
analytic_potato@reddit (OP)
They are one of the places I’m waiting to hear back from!
pittbiomed@reddit
Hold off til you see what they hit you up with flood insurance premium since you have flooded now
analytic_potato@reddit (OP)
We still have to fix the house if we ever want to sell it :/ still owe the mortgage.
pittbiomed@reddit
Good luck and hope it goes well for you guys . God bless ya
rtiffany@reddit
I think everyone should be looking at the 1000 year flood maps and plan accordingly for their property. Even better if you look at it before you buy. The same is true for all other forms of natural disaster. What's the highest wind speed your area has seen? Any wildfire risk above a 1? Largest hail? Highest/lowest temps? It's important to plan out material, elevation and design choices to withstand these things. Especially if you're in an area that may in the next 3-5 decades be reconsidered 'uninsurable' (which will probably apply to anywhere that evacuates more than once eventually).
Remember the modern framework of having insurance and FEMA bail us out after property is damaged is not something that existed a few generations back. People had to make smart choices on where and how they built their homes and live with the outcomes.
Even if it means you have to cut back in other ways, reduce square footage or choose less luxurious finishes, I'd recommend making it a priority to plan as though another even worse event is coming next.
Aggravating-Cook-529@reddit
Hey man. I know you said not to suggest this, but seriously. The weather issues are only going to get worse. Sure we might have a few years where the storms might not be as bad but it will get worse. Figure out temporary ways to make to work till the housing market bounces in your area. Then sell it and get out of dodge.
Good luck.
analytic_potato@reddit (OP)
I mean, the problem is who would buy it now? I don’t think anyone would. We just got this place in Feb and one of the selling points was that it had never ever flooded in 50+ years.
Aggravating-Cook-529@reddit
There are people out there that don’t believe in climate change. I’m sure someone will buy it. Heck people are still paying many million dollars for coastal properties in California, the ones that are falling into the ocean.
analytic_potato@reddit (OP)
Well, it had never flooded in the existence of the home despite being flood zone AE was my point — it didn’t flood in Idalia with a 4ft surge. But yes, it’s not that long.
We are considering leaving when we can. But just… frustrating because I love my home, my community, my work, all of it. But I don’t know if I can handle this happening again.
Aggravating-Cook-529@reddit
I hear ya man. Hang in there.
NohPhD@reddit
Where I used to live in Louisiana people rebuilt their houses on 10 foot pilings. One advantage (in addition to making flooding much less likely) is basically a large garage or carport under the house.
SurprisedWildebeest@reddit
Look at what they do in Venice with flooring, and also the “wet” rooms (bathroom, kitchen, washer) being on the first floor, and main living spaces being on upper floors.
analytic_potato@reddit (OP)
Good idea, will look into this! Thank you.
junk986@reddit
Build on 24ft concrete pilons, concrete structure on top like an oil derric, steel roof, windows have storm shutters. Solar panels and backup batteries. Separate potable and not potable water…I don’t know…a well would too as well as water tanks. If you need cars, they would need to be hoisted up into safety with a lift.
analytic_potato@reddit (OP)
We have a concrete block home and steel roof, impact resistant windows, storm door, and we put up the hurricane shutters, tarped and sandbagged everything. Other stuff I had solutions for — my hurricane kit included life straw type water bottles, 50gal of clean water, lots of non perishable food, solar powered battery etc. Thankfully took both cars with us because it would have totaled.
Not sure if a water tank / well would be possible here but I like the idea.
Halo22B@reddit
I've always loved the "on piling" raised architecture as typified by beach/sound side outer Banks homes. But that would be a complete rebuild for you. Good Luck
Sad_Analyst_5209@reddit
Pilings are great for flooding, not so much for storm surge. A person I follow on Youtube went to Steinhatchee to help a friend. The friend's home was next to the Gulf on eight foot pilings, now all that remains is the pilings.
analytic_potato@reddit (OP)
The water is so incredibly powerful. My neighbor’s garage bent in the shape of a U from the surge trying to get in.
Backsight-Foreskin@reddit
Have you seen those bladders that surround the house to create a levee?
https://www.aquadam.net/
https://damitdams.com/inflatable-dams-inflatable-flood-barriers/
https://youtu.be/Wl-XHN_v7uE?si=i3NjiMockgKhwbn2
analytic_potato@reddit (OP)
Does this work in a neighborhood? Will look. We had a 6ft storm surge outside. Thank you.
OlderNerd@reddit
beat me to it
fost1692@reddit
Lift all of the electrical points, switches etc.
analytic_potato@reddit (OP)
Yes, that’s one of the things I want to do. The only outlets that survived were the ones in the kitchen.
Traditional-Leader54@reddit
French Drain around the outside of the house. It’s cheaper and easier than an indoor French Drain and you don’t need a sump pump.
RonJohnJr@reddit
That's great for water flowing down grade. Not so much for flooding, where the water comes up the grade.
RonJohnJr@reddit
Look to what Louisianans did after Katrina: raised the houses in vulnerable areas.