Caulking Recurring Cracks in Counters and Trim

When cracks along kitchen counters, trim molding and other surfaces keep coming back, no matter how many times they are repaired, the problem is the wall, counter, door frame or whatever, is moving. In some cases the cause of the problem can be remedied with a few well placed nails or screws to reinforce construction. This may be true for walls and ceilings with loose gypsum board. If you can't stabilize your gypsum board walls with screws try using the wall caulking technique on the next page to repair the problem. To repair other recurring cracks try the process below.

For counters, tiled walls or any other surface that can't be stabilized with screws, Use spray foam insulation to hold it in place. The foam will become rigid as it cures and will stop the movement causing the crack. This materials expands when it meets the air and will fill most gaps behind walls, cabinets and countertops.

Use a brand of foam insulation that requires acetone for clean–up. This information will be on the back of the can. Don't use water–based foams, they are too soft when they cure to do any good.

Begin by clearing all loose wall material and caulk from the crack. With wall cracks, use a putty knife to remove crumbling drywall, plaster and other loose material by dragging it thru the crack a couple of time.

Remove cracking caulk cutting it cleanly along both sides of the crack and pulling the caulk free. Try to leave at least a quarter inch gap in the crack to allow the tube on the foam can to enter. If necessary, drill quarter inch holes at six inch intervals along the crack to allow for the tube.

Wear latex gloves and safety glasses when spraying the foam. It will stick to everything and may damage some surfaces so mask any surrounding areas that may be damaged and have a rag and a can of acetone handy for cleaning up spills. Nail polish remover will work for clean–up also. Be careful when using these solvents they will remove the finish on many surfaces including furniture, flooring and painted surfaces, and possibly the dye in some fabrics.

Shake the foam can for one or two minutes and then attach the spray tube and trigger. To avoid unwanted spray, attach the tube to the trigger before threading the trigger onto the can. Don't pull the trigger until the end of the tube is safely inserted into the crack. This foam expands quickly when it meets the air and unwanted spray will be difficult to remove.

Hold the can upside down and push the end of the tube into the void behind the crack. Squeeze the trigger for a couple of seconds or until the foam begins to expand out the tube. When foam has begun flowing, release pressure on the trigger. The foam will continue to flow from the tube, so don't remove it from the crack.

Wait a few seconds for the foam to expand from the crack. If this doesn't happen, then more foam is required to fill the void. Pull the trigger again for a second or two and wait. If the void is not filling with foam within several seconds, pull the tube back slightly and try again. If this doesn't cause the foam to fill the crack try pushing the tube deeper into the crack. The foam must make contact with a solid surface inside the space to expand and fill the crack.

Some spaces will require more foam than others. In areas where the space is minimal, the foam may expand immediately from the crack. If this happens, quickly release pressure on the trigger, pull the tube free and hold a rag over the end. Immediately insert the tube into a new spot.

When a uniform bead of foam forms along the crack pull the can along letting the tube ride just inside to void. If you must pull the tube free to move down the crack, cover the end with a rag to stop the overflow and immediately insert it into a new spot.

When the entire crack has been filled, let the foam cure for at least 4 hours or follow guidelines on the label for curing time. The foam will be rigid and smooth, like Styrofoam, when it has cured. Use a razor blade or other sharp knife to cut the excess foam away. Cut back all protruding foam to insure a smooth repair when re–caulking or patching wall cracks.

Caulk counter cracks with latex or silicone caulk. See Caulking Techniques for tips on choosing and applying caulk. To repair wall and ceiling cracks see the Drywall Crack Repair page.

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