Revisions log for question
How do I fix the darkening of the travertine on my patio?

For several years we have been laying travertine on the patio. Slowly and slowly the ugly darkening has set in. The stone is cleaned 2 times a year with neutral soap and water – but I think the dirt has settled in small pores or depressions. I know you can't use harsh products on travertine, which is limestone. But what can I do?

Or should I completely sand the stone – does any impregnation or sealer for exterior use even make sense?

• natural stone
• travertine