Any suggestions for installing underlayment?

[belfert]

As part of my extreme bus makeover I am installing underlayment so I can install vinyl composition tiles.

Any suggestions on how to attach the underlayment?  I used Liquid Nails adhesive in a can the last time, but that product appears to not be made anymore and nobody else makes anything like it that I can find at Home Depot or Menards.  I'm not sure I want to use adhesive from a tube as I am afraid it might leave lumps.

[H3Jim]

What is the underlayment being attached to?  a solid surface, or rails?  What material for underlayment are you using?

[belfert]

The surface I am putting underlayment on is plywood. 

The underlayment is 1/4" luan that is moisture resistant.  I bought the underlayment from Home Depot.  It is 4x8 instead of the odd sizes that underlayment sometimes is.

[H3Jim]

Maybe some others have some better ideas, but I would use either contact cement or just some floor mastic and use a trowel with fine teeth and spread it out thin.  Weight down the underlayment so its even.

[Blacksheep]

Coming from a pro, you don"t need the underlayment for vct IF your plywood is somewhat smooth. If you have cracks or gouges, simply use a crack filler mixed with a latex for hardness and flexibility. Take the luan back!
BS

[luvrbus]

Belfert, if you are going to use a underlayment I would look at something different I used the luan from HD and 2 years later I am having problems with mine may be the mastic I used but the stuff is lifting not where it meets the floor but the top

[H3Jim]

I'd go with whatever Ace (Blacksheep) recommends.  He knows his stuff.  Maybe send him a picture of it.

[Marcus]

If another 1/4 inch won't matter I would go with 1/2 inch. You will get a better product that won't show every little bump. HD has a good adhesive that is very good. it's a polyurethyne made by dl. I used it to glue my fiberglass skin on the outside of the bus . works great. Marc