I am replacing old drop ceiling tiles and I am bit worried about the current grid layout (which came with the house). The tiles are 2*4 and the current ones are fairly light.
After reading installation documents from several major tile vendors, they all instruct to have the main tees 4' apart, with the short side of the tiles laying on them. Cross-tees between the main tees would be 4' long, holding the long side of the tiles, as depicted below.
BUT, in my case, the main tees are rightfully 4' apart from each other, but then there is a series of parallel 4' cross-tees, resting on perpendicular 4' cross-tees. As a result, one of the long side of the tiles lay on the main-tees, the other side lays on a cross tee which itself rest on another cross tee, as depicted below.
In both cases, there is a wire hanger every 4' holding the main tees. In my current setting though, half of the tiles lays on a cross tee which is not hang to the joist.
The old tiles are fairly light (the yellow mineral wool kind) but the new ones are much heavier. I have a gut feeling that the structure would sag or collapse between the main tees.
Is this grid layout suitable for holding heavier tiles? If not, is it OK to drill holes in the cross tees (the ones parallel to the main tees) and to hang them? ... or is there a better alternative?