Felt carpet with underlay

[Bluedrifter]

Hi, we have bought a fet backed carpet and a ribbed rubber underlay. The carpet chap said we should not use grip strips and sold us a can of spray on glue. Should we stick the underlay to the floorboards first, then the carpet to the underlay?
many thanks for any tips.

 

[mattysupra]

you need gripper! For felt back it should be a velcro gripper. You can use a standard gripper also but not the best.