Terrific concept, design and service...But...they say the product will last 15 years. Mine lasted 5. To be fair, WoodblocX gave a positive response and replaced the affected timbers free of charge with hardly a quibble. The problem was 'brown rot' ('dry rot' as it used to be called – a misnomer because it's caused by dampness). I have now rebuilt the wall with new timbers from WoodblocX and ensured the retaining wall is lined with damp-proof membrane on the inside this time. (It was a pain to pull out plants and start all over again.) Will the new walling work? Who knows, but the firm says their chemical treatments don't work for 'brown rot ('dry rot'). So, as I built I ensure everything was sprayed with a treatment supposed to cope with dry rot (an attempt at 'belt-and-braces). So, excellent concept, great design, easy to build and and good service, but don't be surprised if it doesn't last. Maybe I was unlucky with the fungus in my soil. Using locations that provide for ventilation and sunlight all the time might help (my wall was south facing, but a lot in shade). Wood is wood. Stone next time.