How to Apply a Roof Sealant

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Sealing a roof will help prevent leaks and keep water out of your home. Metal roofs need to be sealed every two years to stay in good condition. They also need to be sealed after storms and damaging winds. Sealing a roof is much simpler than other jobs on the roof, such as installing shingles or metal roofing. Sealing a roof is not very time-consuming and can go a long way toward keeping a home leak-free.


Step 1

Inspect the roof, looking for cracks and gaps that may be causing leaks. Remove any flaking from the current roof coating with a wire brush. Look closely around seams and sweep away the debris with a broom.

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Step 2

Look over the roof and remove any loose debris and reattach any screws that are sticking up from the roof. Check for mildew spots and treat them by rinsing with chlorine bleach.


Step 3

Wash the roof thoroughly with a garden hose. Verify that there are no puddles forming. These puddles can form if the house is not level, there is an indentation in the roof surface or if the gutters are clogged. Dry off the roof with clean rags.

Step 4

Cover all seams and edges of flashing with patching cement using a stiff-bristle paintbrush. Overlap all of the seams by 1 inch and also cover any screw heads. Be sure to cover all roof seams, flashing and J-rail because these are the three areas where most of the leaking occurs. Let the patching cement dry for at least one hour.


Step 5

Mix the roof coating and begin applying with a roof brush. Brush over the entire area of the roof and carefully follow the instructions on the label for proper coverage. Start on one end of the roof and work toward the other side. Do not apply too thick of a coat as it will dry and crack over time. Climb down the ladder and allow time to dry.



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