hi all, we are thinking of installing aluminium casement window grilles at the kitchen. choosing casement instead of sliding grilles because we feel that it is easier to hang clothes out of the kitchen windows with casement grilles. however, our contractor advises against this. according to him, the grilles will start to droop after sometime because the casement aluminium grilles are fixed using rivets and the rivets are not strong enough to support the grilles over time. any comments on this? thanks in advance!