For a wooden subfloor you will need to use a 2-pronged moisture meter. This should be stuck into your wooden subfloor. A dry reading will be 16% MC (Moisture Content) or below. With a concrete subfloor you should use a digital hygrometer, which needs to be left in place for at least 24 hours.
The best way to test if the subfloor is really dry is to use a wooden floor moisture meter to measure the moisture content. If you're working with a concrete subfloor, the moisture content, or MC, should not exceed 6%. If the subfloor is made of wood, plywood, or joists, the MC should be under 16%.
One of the most common signs of moisture damage in hardwood floors is cupping. Cupping is when the boards expand across the face and create sufficient pressure at the edge where the boards meet that the planks curl, or rise at the seams between the boards This can happen for multiple reasons.
Opening up the windows and letting fresh air flow can help hasten the drying process and eliminate any remaining moisture. Open as many windows as possible and let fresh air circulate throughout the room. This will help bring down the humidity level and eliminate any remaining moisture in the wood floor.
Aside from discoloration in the flooring installation, damage from water can cause planks to become loose. Over time, warping and buckling is an issue as well, due to excess moisture.
If the water damage was not extensive, you might want to consider replacing the flooring with new laminate or hardwood. However, if the water leak has resulted in mold growth and persistent moisture under your floorboards, it is preferable to cut your losses and replace the old floor.
The Problem: Cupping
This happens because more moisture is absorbed by the unfinished underside of the boards causing the bottom of each board to expand more than the top. The result is a wavy appearance and each course of wood is raised at the seams. In most cases the wood is not ruined.
If the floor feels springy and spongy when you walk, the subfloor might not be completely attached. Another reason for a soft floor could be from overextended joists; meaning the joists holding the house up are too long and not supported enough.
There are many signs that your damaged subfloor should be replaced with a new subfloor. These include squeaks and other noises, cupping or warping, cracked or popped tiles, sagging or unevenness, the smell of mold or mildew, or bubbling tile.
Subfloor Damage
If your foundation has settled since the house was built, your subfloor may have also settled, creating a dip between the boards on top and the subfloor boards beneath. This can cause low spots to form, which can also be perceived as soft spots. You'll need a professional to repair the plywood floors.
If a house's foundation settles unevenly, it can damage the subfloor and, subsequently, the floor itself. A gap between layers can form, and the floor above it may develop soft spots. Rain or snow that fails to drain, improper landscape grading, or a shifting foundation can cause similar problems.
Water always travels to the lowest spot it can. This means, even if you have removed excess or standing water from the top of your flooring, there may still be water that has seeped underneath your floorboards into your subfloor. Water underneath your flooring does not dry out as quickly compared to surface moisture.
Gorgeous hardwood flooring can add a special touch to any home; yet, beneath them lies a potential hazard: mold. Mold is an insidious fungus that grows in dark and moist spots, so the area below your flooring could easily become its breeding ground if moisture exists there.
You'll know there's water under your engineered wood floor when your floorboards start to buckle and warp. Similarly, flooring made from genuine hardwood is also a permeable and will absorb any water that comes in contact with it. Excessive moisture will cause the flooring to warp and discolor, ruining it permanently.
Within the first 24 hours of a leak or flood, mold development, damage to floors, walls, and electrics, and even structural issues can occur. This is why it's always best to quickly hire a water cleanup pro near you for a consultation and repair.
Amazingly, even if the structure or the subfloor is not exposed, dehumidifiers will be able to draw out the moisture from inside the walls and underneath the flooring to dry out the materials.
Fungi release microscopic spores that drift through the air, or in the case of subfloor mold, up from the floor you walk on each day and into your lungs. Truly the only way to check for a spread in your subfloor is to tear up the flooring, with the help of a licensed professional of course, and visually inspect.
A general rule of thumb, according to the EPA and the CDC, is that mold can start to develop on surfaces within 24 to 48 hours of water exposure. However, at this stage the mold spores are not easily visible to the naked eye. It usually takes around 18 to 21 days for the mold spores to colonize and become apparent.
Mold growths, or colonies, can start to grow on a damp surface within 24 to 48 hours. They reproduce by spores - tiny, lightweight “seeds”- that travel through the air. Molds digest organic material, eventually destroying the material they grow on, and then spread to destroy adjacent organic material.
The most obvious is a spongy feel or “give” to the affected area. Other signs of water damage include warping in the floorboards of your hardwood floors, loose sections in your tile floor, bubbling or peeling in linoleum, lifting in your laminate flooring, or a musty smell that could indicate mold growth.
In some cases, a slight slope may be normal and not cause for concern. However, if the slope is severe or getting worse over time, it could be a sign of a serious problem that requires immediate attention. One potential risk of sloping floors is damage to the structural integrity of the home.
While sagging floors are unsightly, they can be dangerous as well. A sagging floor means that it has lost support, and it may eventually collapse into lower levels of the home. The overall structure of your home could be at risk, therefore making repairs a priority is imperative.
Many homeowners and owners of commercial property have dealt with a sagging floor. Floors can sag for many reasons. For instance, they may sag due to the natural settling of your property or building materials over time. However, a sagging floor may also signify damage from water leaks or pests, like termites.