"Ladyluck, I appreciate your kind words. Posting is always a challenge - say too little and you confuse, say too much and you bore."
You're very welcome. Actually, I think I bore my friends talking about this stuff :lol:, so I appreciate this forum where people are trying to think through it and are willing to share info, experience, etc.
"Flooding is a matter of degree - for every place that is completely submerged, there are hundreds of places where the waters were only chest high, waist high, knee high, or less. We're building houses, not submarines. That place I mentioned with the receptacles at 5-ft.? The area could be counted on to flood anywhere from knee-deep to waist-deep every Spring. Sure, there MIGHT be a worse year ... the point was to design to reasonable expectations."
Agreed. My own house was not in a flood zone but, by the time it got here, the surge was 8 1/2' ASL and that was enough to push 46" into the house, i.e. enough to affect sheetrock, appliance motors, the HVAC (which was on the ground), and Romex and receptacles. Furnishings that were old (= solid wood but not oak), the old heart pine floors and clothing and rag paper books actually fared well but that's a topic for a different thread. And all the houses (100s at this point) that I've worked on in disaster relief got that much or more water. Some were in known flood zones but others weren't (5 miles from the beach on the Gulf Coast, it went over the roof of a house 8' up on pilings!).
You bring up an excellent point with "reasonable expectations"; that would be partly determined by the code (the new one to be adopted, no doubt, after a disaster) and partly by the building owner's assessment of risk and desire to mitigate that, as well as his financial ability to do so.
"ADA "rules" place receptacles at 18", and - as I'll discuss later - this can make a huge difference in flood damage. Contrast this to the desires of some to place the receptacles as low as possible."
I've been thinking about receptacle height, even more so since you mentioned it, and the only reason I can think of for keeping them low is aesthetic. Having poured more sweat equity than I can count into houses I don't own and plenty into my own house, aesthetic is no longer the only factor in my decision-making.
"I wasn't clear enough what I meant when I referred to 'salt.' I didn't just mean salt air and coastal exposures. I did not mean sea water. No, I was referring to the salts (not table salt) that are used to make things like insulation fire and mold resistant. Even gypsum - the stuff drywall is made of - is a kind of salt. That stuff is just fine, as long as it's dry ... but water-soaked insulation will create a very corrosive 'micro environment' all around it as it dries, and that means the wiring devices are going to corrode."
Wow, I had never thought of that. You're right. I do know that drywall is my least favorite building material. The paper covered version grows mold very well; we encountered big tarantua looking stuff in Ft Pierce FL and just-as-nasty other stuff elsewhere.
An aside that might interest some people: when we were working in FL and NC in 2003 and 2004, the standard mold treatment (mostly due to fiberglass holding the moisture in the walls because of its starch binder) was spraying with clorox after gutting to the studs. After Katrina, they began requiring mold mitigation specialists. I've been reading about blasting with dry ice as a treatment and that makes a lot of sense; less mess to clean up, probably.
"Most of my "writings" are at various forums, like the one at Fine Homebuilding. Most often, they're in the context of a flooded basement, or 'finishing' a basement. No matter; the same issues arise.
Here's the thing to remember: materials 'wick' water. 1" of water on the floor will wick 6" up drywall and 12" up any fiberous insulation."
I learned that the hard way. Thought my clothes were safe in the days after Hugo, since they were hung above the water line. However, the closed rod was held by molly bolts and the water wicked up, softened the sheetrock and down she came! I cannot tell you how discouraging it was to hear that sound and see all those clothes down in the mud.
"Framing lumber is pretty slow to absorb water"
Granted, we came on the scene weeks or even months after the storms but the framing was definitely damp and took a while to dry out. That's why we focused on clearing and gutting, to get houses to the drying stage as quickly as possible.
"the steel channels of metal framing trap water in the wall."
Another think I didn't know. I wondered if the rusting that would surely occur would compromise the structure. The one structure I mentioned on the MS coast that withstood the storm surge was powder-coated. It sounds weird for a little old lady to say this, I know, but it was beautiful
.
"I think you can now see why I say even 'little' floods can cause an expensive repair bill."
Absolutely in agreement with you.
"You'll never keep water out; the key is providing good drainage."
You made me remember that, when my son was little (and very messy), I wanted to build a concrete and tile room for him, with a drain in the center of the floor and nozzles all around so I could instantly clean his room.
"First thing to address are the floors. It's amazing how many floors have high spots at the doors and around the sump pump. Think about throw rugs in place of wall-to-wall carpet."
And use materials that don't buckle. Oak flooring, even old stuff, will buckle right out of its moorings. Anything layered will probably delaminate unless it's glued with waterproof glue (not as common as you would think for flooring). And you're absolutely correct about carpet. The only thing it's good for after a flood is for cutting into 4' wide x 8' long strips and using as skids to cart out the debris. We got to where we preferred that over wheelbarrows because it cut down on the volume of stuff we had to pack for a mission.
"Next are the walls. Keep the drywall, etc., from ever touching the floor. The only thing touching the floor should be your non-absorbant PVC trim or rubber Cove base. If you're using metal framing, every stud bay needs a 'weep hole' in it. Use a scribe, awl, or nail to make one. Consider using non-absorbant materials - Tileboard, Foam insulation, etc. - for the lower part of the wall. "
Excellent points. A chair rail with solid wood below is aesthetically pleasing, too. The houses with solid wood paneling fared well in every storm-hit place we've been (my own house included).
"Electrically? Well, if your panel is in the basement, I'd make sure I could kill power to it from above grade somewhere. Give serious thought to where you want the pump power to come from. Plan your circuits so each room can have multiple blowers running."
All good points. Thank you. And thank you for sharing these more widely, too. Fine Homebuilding has wide distribution and I'm glad you've spoken through it. I do believe you're right that it is wise for us to plan for such disasters. And, hopefully, not need it.
Blessings on you...
