How to Seal a Tin Roof

a tin rooftop
  • 8-12 hours
  • Intermediate
  • 55-150
What You'll Need
Roof patch sealant
Paint brush

A tin roof can look great on a building. However, it needs to be sealed to protect it from the elements. Depending on the sealer used, it can also lower the temperature inside the building, which can be very useful in summer. It’s not a difficult procedure, but do allow ample time and don’t try to rush things. A job well done takes time.

Step 1 - Preparation

Check the weather forecast and pick at a time when no rain is forecast for a couple of days. This will give you ample time to work and for the sealant to dry properly.

Use a broom on the roof to take off all the debris and dirt. Complete that part of the job by washing it with cleaner and a brush then hosing dry. Inspect the roof for any holes, especially where it’s been screwed to the studs. Also, remember to check the flashing for leakage.

Step 2 - Patch Sealant

With a clean, dry roof you can begin by using patch sealant on the tin roof. Make sure to apply this around screw holes, where seams overlap and by the flashing. It creates weatherproofing so that water can’t enter through vulnerable areas. Cover all these spots, painting the patching cement on the tin roof heavily using a thick brush. Once you’ve finished, give it ample time to dry.

Step 3 - Sealant

Stir the sealant properly. To apply it you should use a roller, preferably one designed for this rather than for applying paint. Ideally, you should begin with a thin coat, being certain to cover the entire surface of the tine roof, including the areas you covered with the patch sealant. If necessary, use an extension on the roller to avoid standing on the roof and ending up with sealant on your shoes. Depending on the style of the tin roof you will probably also have to use a paintbrush to reach into the less accessible areas of the tin roof. Go slowly and be thorough in your work. Allow the coat of sealant to dry.

Step 4 - Second Coat

Apply a second coat of sealant to the tin roof in exactly the same way, being sure that you cleaned the roller and brush between coats. In moderate climates, two coats should be ample to protect a tin roof, but where there are greater extremes, three or even four coats can be more advisable.

Where the summers can become extremely hot, using an aluminum coating on the tin roof can prove to be beneficial. These reflect most of the sun’s rays and this results in lower temperatures within the building itself, in some instances making the indoor temperature 15 degrees Fahrenheit lower. After applying the final coat of tin roof sealant you should leave for 24 hours in order for it to dry fully. Clean the equipment you’ve used and put it away. Your tin roof will now be fully protected.