Hurricane Harvey that hit the Texas coast in August 2017 did some massive damage and dumped over 50″ of rain in some parts of the state. Houston, TX got the worst of the flooding and I’ve been asked every day since about my advice regarding cleanup. This blog post is meant to give you a quick overview of the post-flood clean up process.
1. Protect Yourself First.
Before we get into the specifics of the process let’s take a minute talk about PPE (personal protective equipment).
Most of this PPE is pretty straightforward with rubber boots/gloves/clothes, but the most important gear I want to mention here is protection for your lungs. The demo work you are about to engage in may have lead based paint that can/will get airborne during your demo work so respirators are vital (assuming the building is older than 1978). But even if you are working on a newer building at the very least you will stir up dust and mold that can be a major nuisance (or worse). At a minimum use a N95 mask $3ea respirator (I like the N95 with a venting port), or for the best protection use a half-face P100 respirator $15ea.
Next, be sure to check for hazards inside the house before beginning work. Cut off power if electrical outlets have been wet, shut off the gas into the house, and turn off the water line at the meter (mainly so you don’t accidentally cut a gas or water line).
2. Demo & Dry
Remember that dampness supports mold, bacteria, and pests so trash out anything that’s wet and can’t be dried. Carpets/Pads are probably trash if this is a flood from outside the house as the sewage is tough to clean out of carpets. Cut your sheetrock from 1′ above the flood line and remove all the wet stuff below. Cut your insulation where it’s dry and don’t yank it down or you’ll be left with gaps above. Hardwood floors might be able to be saved but it’s touchy. Typically I’d say demo to studs and to your concrete slab. Trim might be able to be saved if it’s solid wood, but any MDF or Particle Board (think Ikea cabinets) are trash after a flood.
3. Clean & Disinfect.
Ok so now that the house has been demo’d down to the studs it’s time to clean and disinfect. Use a broom and shop vac to clean up silt and debris, get it really clean inside. You might also hose down the house with clean water. Don’t get anything but hard surfaces wet. Studs, slab, etc. These can all benefit from a hose down to get it really clean. This will help wash away bacteria too. Don’t powerwash or get the dry sheetrock wet however.
Next, use a disinfectant to kill the bacterial growth that happens from sewage in floodwaters. Microban is a good option but it’s not something you want to breath in yourself. Use your mask, gloves, goggles, etc. Use the recommended dilution and use a pump sprayer to soak everything that got wet with a mist of this to kill all the bacteria. Another option is to use a bleach solution (roughly 1/4-1/2 cup bleach to a gallon of water) but be sure not to wet metals as they will corrode with bleach contact. Keep kids and pets away during this disinfecting stage.
4. Ventilate and Dry.
Now that the house is demo’d and clean it’s time to get everything dry again. Open all your windows/doors if it’s nice outside and get air flow going. Use fans of any/all variety to blow on the wet studs and surfaces. If you are a contractor be sure to buy the Carpet Dryer fans. These fans blow tons of CFM’s and work for years. Otherwise, even a $15 box fan will move some air and speed drying. Remember that mold only grows where things are damp so you want to get everything in the house as dry as possible as soon as possible. Consider a Dehumidifier if you are closing down the house at night or if the weather is wet/humid.
5. Verify and Treat for future mold growth.
Last step before considering any rebuilding efforts is to ensure the house is dry. I use a Moisture Meter to probe the wood near the ground for moisture content. Ensure the whole house is below 20% or ideally below 15% moisture content before moving on.
Once it’s verified dry then I’d recommend a final treatment to ensure mold won’t grow. I prefer BoraCare Mold but Concrobium might be easier to source (they sell it at Home Depot). Both of these apply with a pump sprayer and you’ll wet down the surfaces of all the building materials. These are less toxic ways to keep mold growth down in the future, but the most important thing to remember is to keep the house dry!
I hope this quick guide was helpful, but if you want more info on this topic I’d recommend these two links.
HUD Guide to Disaster Cleanup https://portal.hud.gov/hudportal/documents/huddoc?id=Rebuild_Healthy_Home.pdf
FAQ Flood Cleanup LSU http://www.lsuagcenter.com/profiles/sfiser/articles/page1474660090140
For more info on lead hazards and your cleanup visit: http://www.epa.gov/lead
Risinger & Co