Before we talk about some home owner remediation techniques lets address very briefly some preventative maintenance. Realize that water is the greatest enemy your home will ever face, and too often moisture issues go unnoticed or simply unbothered. Either the home owner doesn't see it or they seam to have some disillusioned idea that it will go away naturally. To start, if the water damage has occurred and you're willing to tackle the task dry everything quickly.
Carpet absorbs moisture and mold spores, providing a breeding ground for bacteria and fungi (which is why carpet should never be used in a bathroom). If it’s a lot of water, as in it needs to be measured in gallons, use a shop vac to pull the moisture out. I once had a pipe burst (my dumb fault not the weather) during a remodel project; in the time it took me to get the rusted water main turned off (it’s about 200 Meters from my front door) my house had 25 gallons of water rushing underneath all the hardwood floors. At this point in time it was too late for preventative maintenance I simply had to get the water cleaned up. The first step was the shop vac and sitting there for several hours syphoning the water up. Once it’s underneath the hardwood it was a matter of creating enough suction so I could pull the water from the living room through the opening in the bathroom.
Ok so now we have the majority of water cleaned up. Mind you if this had happened on carpet the pad and rug would have retained a larger percentage of the water, so you would not have been able to vacuum as much water out.
Next step was to get as much of the remaining moisture out as possible within the first 48 hours. Much like the crime show on television after 48 hours you're looking at a significant mold problem because in the time it took you to vacuum everything up… You've already got mold!
Forget the electric bill with the AC or heat you're going to have to sacrifice there. Depending on the size of your spill open up the windows surrounding the area and turn on any exhaust fans immediately available. My particular incident involved the half bath and the living room with the connecting hallway, so all windows in the living room and the exhaust fan in the bathroom were opened (for good measure I opened a few more, better to error on the side of caution).
The bottom line here is we have now increased the relative humidity (RH) in the air and it will continue to stay high and transport water unless we can get it out of the house. Keep in mind that water will travel in the air through walls and then you have a condensation and MOLD issue behind your walls, so don't be stingy open the windows. If you're really lucky you've got a wood stove going and its winter so not only do you have exceptionally dry air but a heat source to crank up and aid in drying. Mine was unfortunately in the middle of the summer in Alabama.
Next stop you need to hit the local hardware store and get some fans and ideally a dehumidifier (If it’s a bad spill you will need to hire a professional with a large industrial sized dehumidifier). Once you are set up to get the air circulating and the moisture removed from the structure you've done about all you can. If it’s hardwood go ahead and remove the trim work so you have plenty of room for expansion and cupping of your boards. They will typically settle back eventually but it may take several months! and until then you need to leave room so boards wont push up and damage the moulding.
Any water damage on drywall can typically dry in place provided there is no swelling and the seams aren't pealing. However, if either of the above are true go ahead and remove the drywall and get a fan on the opening to let it dry. You can come back and fix it the next weekend after it has thoroughly dried. Keep in mind that it may be worth your peace of mind to pay an inspector to come out with his moisture meter and measure the moisture content (MC) in the wood before you put drywall back on; for that matter it’s definitely worth getting a mold test done before you start any repairs.
If you're house has shiplap siding or lauan board from the 70’s go ahead and put your pry bar behind it and peal it back a touch to let the air reach behind. If it’s lauan or another type of wood paneling that is not shiplap I recommend complete removal for aesthetic sakes!
Insulation is usually best if it is just tossed and replaced; it retains a lot of water, it’s hard to dry, and rarely performs as well after having been wet. If it’s just little damp you can try to get away with a fan on it but I would make sure it’s completely dry before putting up new drywall.
Keep in mind that the remediation techniques I’m talking about are for potable water only. If you have a grey or black water spill you need to call a remediation company to handle it for health, safety, and legal reasons.
Now for the question you asked to begin with… what about mold? before you can treat the mold you have to identify the kind and amount. Basically we are relatively certain you have mold, you may have even seen a bit but you should know the extent and the mold test will tell you the types of spores in the air and the amount present. Basically this can tell you if it’s something you can handle as the do-it-yourself warrior or if you need to hire a professional industrial hygienist.
Mold jobs are broken down into three different sizes: small - less then 10 sqf, medium - less then 100 sqf, or large - more then 100 sqf. Anything in the large category needs a mold remediation professional pretty much regardless of what the test results show. This is where it is somewhat redundant to get a mold test if you see it and it’s this large, but again it can make a difference to the hygienist for the treatment options. The only exception is to know the type so it can be treated appropriately.
If you elect to work on it yourself it’s important to take into consideration your personal protective equipment. Now you’re not attempting to be a professional remediation service and I’m not attempting to guide you in to that realm, but here are a few tips to keep in mind with your PPE. I’ll make mention that it is always best and safest to hire a professional company this is only for those cheap skates out there that wont listen to that advice.
Tyvek suits cost about $8 and provide some degree of protection from spores and contaminants. Not typically the same as what the pros use bit it will do for your home remediation project. Gloves are every bit as important and you can purchase mold and bacterial specific gloves however a set of rubber dish gloves can go a long ways for the DIYer.
In truth, you could probably get away with the N95 mask from the hardware section but I would recommend you just purchase the respirator. Ensure you get one that has a good seal around your face and has the appropriate filter. 10 years ago I could have listed out the types of filters but now there’s so many, just read the back of the box at the store and it will tell you. Go ahead and purchase one that has a 99% particulate rating. You can reuse the respirator next time you paint or sand something so don't feel like it’s a waste of money. Over-booties can help but if you have trouble finding them just duct tape the ankle of your pants around the boot.
Now we move on to containment. You have to be able to keep the mold spores from spreading throughout your house. containment can vary depending on the size and shape of the room but the general concept is to create a negative pressure room that keeps spores out of the house. Grab yourself a roll of painters plastic, duct tape, and a fan. You might need some PVC pipe and fittings too but we will come back to that in just a minute.
If the room is a stand alone room like a bedroom turn off the HVAC (you don't want it to circulate the spores throughout the house). Get all your tools inside the room so you don't have to leave and a few contractor bags and a handful of zip ties. Close the door and cut a piece of plastic to fit all the way around then duct tape the seams. You can leave the floor portion un-taped to circulate new air in to the room. Next Seal of any vents or openings entirely and brace the fan (blowing out) in the window. Then seal it the same way leaving only the back of the fan exposed.
If everything is done correctly when you turn on the fan the door seal should pull inwards like it’s trying to collapse, and you should have a decent draft of air coming underneath the door. Do not let that get lose though you shouldn't have much gap at the bottom; you need to ensure that no spores can make their way back in to the house.
Now if the room is a large open great room then you may need to build a box to work in, out of PVC pipe and cover the entire thing in plastic. If you're in a bathroom without a window you can use the exhaust fan but it may not be powerful enough to provide good suction, and if the pipe is long it will get mold spores in it, so be sure and vacuum it when you are finished.
Now start cutting out all the bad components wood, drywall, etc. don't try to pour bleach on porous material and hope its treated, it wont work. If a piece of wood has sentimental value it’s better to have a professional take care of it. Once you've gotten everything removed now bag it in the contractor bags and zip tie the end, then double bag it and zip tie the next one.
If possible remove the bags through the open window to avoid dragging spores through the house. Make sure they are disposed of in a manner legal and appropriate with your jurisdiction. A pro will likely leave an air scrubber working in the room for several days or at least during the remediation but without that option make sure everything is vacuumed viciously.
Once everything is dry and all the dust has been vacuumed you can begin rebuilding. Do not rush this step or you'll be starting over! leave any openings exposed for a week or two to let everything air out, keep the containment up and the fan running during this time to transport the remaining spores to the exterior. When you're ready move the plastic and fan through the window, if that’s not an option bag them in contractor bags and dispose of them as you did the construction debris.
One final note before beginning the rebuilding process, it is worth it’s weight in gold to hire an inspector to perform another mold test to ensure you have removed all the contaminants. This may be expensive depending on what needs to be done. Ideally, you will take an exterior sample as a control and an indoor air sample in the room affected. However, if you want to take true diligence and ensure it is gone the inspector can take a sample behind the wall and a surface sample on any areas affected. I have a biased opinion but don't skimp here or you will be starting over in a few months of allergies.
I am a United States Army Veteran with over 10 years construction experience prior to my service. After my time in the military I enrolled in InterNACHI's rigorous course work to become a certified member and prepare for the National Home Inspectors Exam. I continue to push inspection courses and education, attaining and exceeding the required continuing education courses