One main support for mattress slats was installed on the wrong side of back panel and I had to remove it then Mark up drill and refit on the correct side. A few predrilled holes for he dowels and screws were drilled too big so dowels were loose and screws did not bite properly. On the whole though the rest is very sturdy. I had to use some larger screws and glued all dowels. The rest of the beds seem pretty solid and once modified and glued it made a pretty solid bed.