ASK THE INSPECTOR: Finding kitchen moisture source critical

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This article was published 24/11/2012 (4811 days ago), so information in it may no longer be current.

QUESTION: Recently we have noticed a sizable hump in our kitchen floor which has been getting progressively worse. We have a very high-end laminate floor and it seems to be lifting along one of the seams directly beside the refrigerator. In the past we have checked for any water damage from around the sink and dishwasher and also see no damage to the basement ceiling. Our basement is unfinished so visibility is good. Today we pulled out the refrigerator and noticed that the toe plate on that side of the counter is swollen and very dark. It looks like water damage but we can see no sign of any wet areas or stains. Could the refrigerator be causing this problem? It is well-vented according to the manual, however it has a bottom-mounted freezer.

Could it be causing condensation of some sort? If you feel that it is indeed a moisture problem, as we suspect, what options would we have? Do you have any suggestions of where to start to correct this problem? Your opinion would be very much appreciated. Best regards. Cathy and Stan Falk

ANSWER: The damage you are seeing to your kitchen floor is undoubtedly due to moisture and finding the source is critical in solving this problem. There are several possibilities and they should be eliminated one by one until the true source is found, and then actions taken to stop further deterioration.

It’s understandable that it may have been difficult to locate the source of your buckling flooring initially. Because laminate flooring has a very durable surface, but a substrate that is very susceptible to moisture damage, deterioration may go unnoticed for some time. When water seeps through the joints between the individual planks, or gets under the flooring itself, the fibreboard core may begin to swell without any visible signs on the surface. Often, it is too late to do anything to stop further deterioration once this has occurred. For this reason, I always caution my clients to quickly wipe up any water that drips or spills onto the surface of laminate flooring, especially in kitchens. I also recommend against using this product in any bathrooms for the same reason.

While it is possible that the initial bump in your floor could be due to typical floor movement and shifting, the swelling and staining at the bottom of the kitchen cabinets is a dead give-away for water damage. Somehow, moisture is being absorbed by the particleboard in this area, causing similar deterioration to that seen in your flooring. The question to address is where this moisture is coming from.

When trying to identify the source of something like this, I always start looking at the most common culprits. If the kitchen sink or dishwasher are directly adjacent to this area, start there. It is quite common for kitchen faucets to drip undetected, especially from retractable hoses for spray wands, inside cabinets. If the bottom of the cabinet is solid, without any pipe protrusions or holes, water damage is normally seen in the cabinet itself. If the cabinet has any openings, particularly in the bottom around water supply or drain pipes, look there first. While it may not be readily visible with the naked eye, try pushing a rolled up paper towel into these openings until it touches the actual subfloor and see if it comes out wet. If it is damp, you have likely found the source of the water.

A dripping or sweating water supply pipe or faucet can produce a lot of moisture, which may be running along the subfloor beneath the cabinet. This may run downhill until it reaches an obstruction, in your case the cabinet gable or kick plate. This water will be wicked up into the man-made, wood-based cabinet, causing the swelling and staining you have observed. If there is enough moisture, it could also run underneath the cabinet and eventually be absorbed into the base of the laminate flooring. This would certainly cause the flooring to buckle as it swelled, creating the floor hump and lifting floor seams you have observed.

If the area under the sink and cabinet are dry, and no visible leakage or moisture is seen on the water pipes in this area, the next probabilities are the dishwasher and fridge. Built-in dishwashers can be problematic when there are leaks, because the water supply connections, and a good portion of the flexible drain hose, are hidden underneath. To accommodate this, most manufacturers have easily removable kick plates to inspect this area. Once you have removed this metal covering, shine a good flashlight in this area and look for pooling water. If none is visible, try the paper towel trick again, this time laying out a sheet or two flat, to see if any water is absorbed. The best time to evaluate a leaking dishwasher is right after a complete cycle, as the leakage could also be through the door from a damaged gasket or hardware. If nothing is visible from this and the sink, move on to the refrigerator.

While I am not very familiar with the components of the newer bottom-mounted freezer units, most modern fridges have integral defrost mechanisms. These defrosters can become blocked with dirt or other obstructions and can leak water. If there is an evaporation pan underneath the fridge, it will usually catch any of this excess water, where it can be harmlessly dried, but these can also become damaged or overflow. Pull out the owner’s manual and see if there are instructions for cleaning or inspecting the defrost system. If this is the item responsible for the water, doing the required maintenance may solve the issue. If you can’t find this information, and it appears that the fridge is leaking or condensation is forming on the outside anywhere, call an appliance repair company immediately.

Unfortunately, once laminate flooring is swelled, replacement of the damaged sections is the only repair. Hopefully you have a few extra replacement planks saved, but this can only be done once the cause of the damage is found. While it appears obvious that water is causing this damage, finding the source and stopping it may be a little less simple.

Ari Marantz is the owner of Trained Eye Home Inspection Ltd. and the president of the Canadian Association of Home & Property Inspectors – Manitoba (www.cahpi.mb.ca). Questions can be e-mailed to the address below. Ari can be reached at (204) 291-5358 or check out his website at www.trainedeye.ca.

trainedeye@iname.com