English to Swedish Tech/Engineering Mechanics / Mech Engineering underdrain laterals

Från en installationsanvisning för filter för reningsverk, se

http://www.severntrentservices.com/eNews/vol21/filter_floor....

"Failure to place the fill grout within 24 hours after underdrain laterals are set in base grout may result in a reduced strength underdrain structure or failure of the underdrain system."

Tack på förhand!