Hi sanjali, sorry I didn't see this post earlier - were you able to solve this design dilemma yet? How'd everything turn out?

Check with your local brick supplier. Most of them sell a thin brick that goes on just like tile (just use a tile mastic adhesive). It doesn't make near the mess as using using full size brick so it works well in existing spaces. A word of caution: The brick tiles do cost significantly more than full size bricks. Here is a pic of a similar product and some pictures from a basement we just completed that used the tile brick as a fireplace surround and an accent wall in the kitchenette.

Yes, as Cornerstone says, please don't redo the water-proofing if it has already been done once. Tiles are a far better option than decking with composed fibre-wood. No matter how hardy the latter material is, it is going to be a muddy and wet area, so please go with a good anti skid ceramic tile. Check on the final use with the manufacturer- that it is going to be laid on the terrace and exposed to sun. Use at least 3 mm spacers to allow for some expansion over a period of time. Also leaves enough space to insert waterproofing epoxy and secure the tiles

Brick tiles vary a lot in costing. You may need to visit the store with wall sqft area to be covered. Select the material and then arrive at a cost including labour. You may also have to add the scaffolding costs. Try to keep 5-10 percent towards breakage and wastage.