Laidoffsick posted:As the layout moves over time with contraction and expansion (yes, even in a climate controlled environment) anything like wood filler or spackle is just going to crack becoming visible again, even through your ground cover. Best to use something flexible when dried like a caulk, liquid nails etc etc and then cover the joint with masking or duct tape, then paint over it all with a thick layer of latex paint. Even if that joint does crack or separate over time, the tape will keep it concealed below the ground cover.
I agree that a layout expands and contracts (it almost seems like a living, breathing organism) and flexibility is desirable when filling the gaps.
