How to rejuvenate second hand terracotta roof tiles?

[Giz]

Hi, I purchased 12 second hand (reclaimed) terracotta roof  tiles, with an  intention to place these in the void created by removing an evaporative cooler..These tiles match the current ones I have on my roof in terms of brand and colour.  However these second hand tiles have lichen and moss on them.

I have pressure washed the lichen and moss away.  Unfortunately the second hand tiles do look deglazed.

How do I rejuvenate these tiles before they go up on my roof?

Thank you!

[Jason]

Welcome to the Bunnings Workshop community @Giz. We're pleased to have you join us. 

You might like to share a couple of photos of the tiles so members can see what you are working with. 

Let me also tag a few helpful members to kick off the discussion: @Nailbag, @Noyade and @Jewelleryrescue.

Jason

[Nailbag]

Hi @Giz 

You won't get that glazed look back. But since you have already done the cleaning, you could use a product like this to add a gloss finish. Just follow the directions for preparation.

Nailbag

[Giz]

Thank you.  

I suppose this will also help prevent rain coming through the tile into the house right?

[Giz]

 

 

And the existing tiles on roof

 

[JacobZ]

Hi @Giz,

Welcome to the Bunnings Workshop community, it is wonderful to have you with us.

Unfortunately, as the glaze is baked into the tiles when they are kiln-fired, you are never going to get them to look exactly alike, and because of the residual glaze, you would likely struggle getting a sealer to stick.

You could certainly try the product Nailbag mentioned, but I'm not confident it would stick with the existing glaze. 

If you are looking for a perfect match, you may have to purchase new replacement tiles or speak with a professional roof restorer for their advice or assistance.

If you have any further questions, please don't hesitate to ask.

Jacob

[Giz]

Thank you.  I'm not so concerned about the appearance more about the waterproof side.  I have read that pressure washing (which I have done) can cause the tile to lose waterproof ability. Is it safe to say that as long as the glaze in visible then it is waterproof?

[JacobZ]

Hi @Giz,

If the glaze is visible, then there's a good chance it is still waterproof, but you can always just pour some water over the surface and see how it reacts.

Start by making sure it is completely dry, then place it glaze side up on a dry surface. Pour water onto the top so it pools, and leave it for 10 to 15 minutes. After this time, check the underside of the tile. If the underside stays completely dry, you can pretty comfortably say the tile is still waterproof.

Let me know if you have any further questions.

Jacob

[Giz]

Thank you very much!