I am using Flexbed under Atlas track. I was disappointed at how soft the product is. I was expecting it to be similar to the old VinylBed which is very solid. If you drive track screws too tightly, you can create a dip in the track or even separate the tie from the rail. I don't think the weight of an engine over the track will be a problem and if you glue down ballast, it definitely won't be a problem.
Bob
Ok thanks. I am using super O, obviously and have used and LOVED the original vinylbed... but its not available any more...
Now i use a 'floating anchor' design for my track which is really quiet... i can do it on super o because the mounts of the track are between ties like this...
So what i do is cut a .5" x 1.25" plate out of 1/16 aircraft plywood and glue that to TOP of the roadbed. This is hidden by the super o. This is what i screw to ONLY. I ballast around these plates. The screws never touch the benchwork.
Since screws dont engage the benchwork, i wont have the squish issue like you guys.
The roadbed is glued (using elmers) to a sheet of 1in thick foam which is glued to the benchwork. Its really QUIET.
What had me worried is before i ballast, i was thinking my floating anchers may sink into the flexxbed because its softer under weight of heavy engines like bigboys... but this wont be a problem after i ballast because the gap under ties will be filled and the ties will keep the track from sagging into flexxbed at the anchors.
Whats nice about this design is the roadbed can easily be stripped up off the foam and reconfigured if desired. Gluing to wood benchwork would destroy the roadbed if it is to be changed. The foam just lets the roadbed come off easy. The foam also helps you make more dramatic elevations falling below the roadbed level if desired by carving it away. Eventually it is covered by woodland scenics plaster cloth for hard shell.
Thanks for your comments and feedback...