Laminate flooring and water do not mix. A number of floor coverings are considered impervious to water, such as ceramic or porcelain tile, luxury vinyl plank flooring, and especially sheet vinyl flooring. At the other end of the spectrum are floors like solid hardwood, bamboo, and engineered wood that you may want to think long and hard about prior to laying in a full bathroom with a shower or bathtub.
Laminate flooring falls in the latter camp. If inexpertly installed, laminate flooring will be a disaster in high-moisture environments. If installed according to manufacturer instructions, laminate flooring has, at least, a decent chance of standing up against the water.
What happens when water comes into contact with laminate flooring? Though laminate flooring industry specifications dictate tests for laminate flooring and water where the flooring is submerged under water for a full day, irreversible damage happens long before that.
Generally, laminate flooring with open edges will maintain its original dimensions after about two hours of submerged water exposure. After about four hours, the flooring begins to soak up water, and this is considered the point of no return. Higher temperatures will increase the rate of absorption. Boards that begin at 5/16-inch thick will swell to 7/16-inch thick or even more.
Slowly the image layer and wear layer begin to de-laminate from the top of the board. Because laminate is a dense fiberboard, it takes over two full days to dry. Installed laminate flooring may take weeks to dry, if ever. After complete drying, the laminate flooring will never return to its original dimensions. Given this, it is absolutely critical that water is kept away from laminate flooring as much as possible.
Water on Top of Laminate Flooring
Laminate flooring can get wet, but only the top. Laminate flooring’s sides, open seams, damaged areas, and bottoms can never get wet.
Mop up standing water quickly, as water can migrate into laminate’s seams. The edge areas of the laminate are more of a problem since edges are cut and exposed. If the water has reached edge areas or open seams, thoroughly extract the water with a wet-dry vacuum.
If you install the laminate flooring in a full bathroom, you must take extreme precautions given by laminate manufacturers. Installation in guest or half bathrooms without precautions is acceptable because water is not prevalent as in rooms with bathing facilities. In these rooms, the main areas of concern would be around the toilet and below the sink.
Water Under Laminate Flooring
When the water reaches under laminate flooring, the water must be removed immediately. If a small amount of water has leaked toward the edges of the flooring, pull up any quarter-round (shoe molding) or baseboards around the perimeter. If the water is not pervasive, you may be able to extract it with a wet-dry vacuum.
Your best bet is to remove the affected floorboards. Floorboards that run parallel to the spill may be simple to remove (after the quarter-round and baseboards have been taken up) since the last course of parallel laminate boards should tilt upward. You can then progressively take up boards as far as you need.
Floorboards that run perpendicular to the spill, as well as the first course of boards, cannot be removed so easily. In this case, you need to remove all of the laminate floorboards.
Fixing Water-Damage Areas
Many types of floors, not just laminate flooring, are subject to damage when hit with enough water. Solid wood flooring will warp and swell when water-logged. Since wood fibers in real wood run lengthwise, the weak direction is sideways. When natural wood bends in this direction, it crowns or cups. Even water-resistant floors like vinyl can be affected if the water works its way under the flooring and begins to degrade the paper backing.
The difference between real wood and laminate is that real wood can potentially be saved. Even cupped or crowned wood can be sanded down flat. Laminate flooring cannot be sanded. Does that mean it cannot be fixed?
While damaged boards cannot be repaired, they can be replaced on a one-for-one basis. Most installations use packs of laminate boards. Because there is a set number of boards in each pack, it is inevitable that boards will be left over. You or a previous owner may have stored extra laminate boards in a closet or attic. If the board is at the end, remove the baseboard and pull out the affected board. If the damaged board is at the center, cut it out, using a fine-finish blade on a circular saw.
Installation in Water-Prone Areas
Follow these rules for laminate installation in places where excessive moisture may be present, such as in full bathrooms and near kitchen sinks, dishwashers and ice makers.
Fold the underlayment up against the wall two inches. After installing the flooring, cut excess underlayment down with a utility knife.
Be sure to fill the laminate’s expansion areas. Laminate flooring always needs to have a perimeter zone around its edges. This is to allow for flooring and wall expansion and contraction. For flooring that you expect to get wet, this perimeter must be filled with silicone caulk.
Remove the toilet for bathroom installations. Do not install laminate around the toilet. Instead, remove the toilet first, install the laminate, and then re-install the toilet. Leave a 1/4-inch expansion area between the laminate and the toilet flange.
Add wall molding if appropriate. Molding has to be applied to the base of the shower pan or bathtub, and this area, too, must be filled with silicone caulk. As an alternative to using molding, you can leave a 1/4-inch opening and fill that perimeter area with silicone caulk.
In problem areas, apply glue to the tongue portion of the plank, even for lock-and-fold type laminate planks. Do not flex the joints when applying glue. Glue must ooze to the surface as the laminate pieces are locked together. After locking and folding the joint, wipe off excess glue. Allow the floor to dry for 24 hours before using.