Attaching track to foam board

It's hard to get anything to adhere directly to foramboard for long periods (months/years)

My normal system is to use plywood (thin floor underlayment plywood that had a hard wood outer layer like Lauan) as the base for the track. It's hard to get anything to adhere directly to foramboard for long periods (months/years)

I use IBL Cork for the road bed, and Atlas for the track.

Glue the roadbed to the wood with Liquid Nails Construction adhesive. It is easy to work, is tacky right from the beginning, and never completely hardens. This is really useful because everything expands and contracts just a little with temperature and humidity changes from summer to winter.

Glue the track to the roadbed with DAP Weldwood Contact Cement. This stuff bonds quickly, and again, has just a little give to it, so it will stand the test of time.

I also DO NOT solder my tracks together. The solder joints are the same as welded rail. If your track gets warm or cool, it will want to expand or contract. When welded, there is nowhere for that expansion to go, and your once perfect track work could have kinks in it on a warm day. Use multiple electrical connections if you are worried about current loss, but in Z scale, current loss is usually not a big deal because our locomotives do not draw that much power.

If by foam board you are referring to the same stuff that is used in house insulation during construction, I use straight pins to hold the track in place. Then I ballast my track by applying glue to the outside edges of the Micro Trains track and then carefully add the ballast. I have often thought of removing the pins once the ballast has dried, but then decided against it because of glue that holds the ballast letting go over time.

Well.....i'm new to Z scale but I've modeled in N and HO scales in the past. When I started I used the nail down technique which to me became a real pain. My last two layouts, one in N and one in HO, I used latex based caulk to attach the track to the extruded polystyrene base. I think it works great and is a very effective way to lay track. The downside is that you do have to wait for the caulk to dry. I just put a dab of the caulk on that boss on the bottom side of the track that you would normally punch a nail thru. Works great and secures the track solidly! I've found that my track laying has been much improved....I get far less oops!

Dang, sorry-forgot to look, and it wasn't made by "Jet"!!

If you are gluing actual track like Rokuhan or Micro Trains roadbed track-use Zap part #PT-25 "Zap-O Foam Safe CA" to attach it to the usual pink or blue foam we use for our layouts! It doesn't attack the foam like most CA's do, and believe me, it works!! Had to adjust some trackage and it pulled the pink foam with it!!