clay vs concrete roof tiles

[shardy]

are clay roof tiles better than concrete? we are not sure whether to tile our new dormer and what little remains of the rear roof in clay or concrete tiles.
1930's mid terraced house.

The original are concrete but I've read clay absorb less water, and therefore less mold will grow on it. We get a lot of moss dropping off the roof.
But I've also read clay are more prone to crack, especially in freezing weather or if you walk on them. We are South East England so not as cold as some parts of UK.

Also the neighbouring properties are concrete so maybe matching the original as close as possible will blend in better visually
thanks in advance

 

[chappers]

The original are concrete but I've read clay absorb less water, and therefore less mold will grow on it.

The surfaces of clay tiles are generally smoother and therefore attract less moss and algae, but there are some good treatments for concrete tiles that will prevent moss and algae growing.
I used to be sceptical about these treatments but my F-I-L has a house that is in close proximity to a load of trees and the roof was covered in moss and algae, he had the whole roof jetwashed off and a treatment applied and 10 years later not a single bit of moss or algae has come back.
Sorry I can't tell you what they used, but it certainly worked.

 

[shardy]

we opted for the concrete tiles in the end. need to save a few hundred quid