If you see that water no longer drains properly, you can use a quick do-it-yourself fix to unclog and clean the drainage pipes. Follow this step-by-step process to clean the clogged drainage of your terrace.
Run boiling water with detergent mixed in it through your drainage pipes every few weeks to prevent sludge from building up.
Straighten a wire hanger and bend one end to form a hook. Using the hook, take out all the gunk that is blocking the drain.
Boil 2 litres of water, add a spoonful of liquid detergent in it and stir. Pour the boiling water into the drain to dissolve the sludge and fat on the walls of the drain. Repeat the process for a couple of times to allow the drain pipe to run more freely.
Take a cup full of baking soda and pour it into the drain followed by another cup full of vinegar. Let the mixture sit for 15 minutes. Then pour a bucket of boiling water for the final blow.