New floor, spray or not?

[richardrich79]

Laying new 150x21 redwood t&g flooring in a room which had a (small) woodworm problem.
All the old infected wood/joists have gone and all new and original joists liberally sprayed twice with Cuprinol 5 Star complete wood treatment.
I've insulated between the joists with 50mm Recticle and a membrane is going under the new planks.
The new boards are going to be painted.
Question is: Should I spray the underside with the wood treatment? or is that totally unnecessary?
Thanks in advance

 

[ree]

Why is a membrane being used? Is the sub-floor void wet or damp, or lacking in adequate ventilation?

Its most likely to be unnecessary to spray anything else - on condition that all bugs are dead. Did you actually see any live bugs or light colored frass?

Has all the cellulose debris been removed from the sub-floor oversite?

Go under the floor in a year's time and check for bug holes.

 

[richardrich79]

I've only just seen your reply.
The membrane is being used as I was gifted a couple of rolls and under some of the other rooms we've used insulation roll supported by nylon type mesh.
I've been obsessivaly cleaning under the floor so theres no debris at all and a good airflow.
The 'crawlspace' is only 12-18" so once the floors are down there will be no easy way to inspect anything bar the upper surface.
Cheers