Sorry for long post but all info should be here
Just got back from nec homebuild show and Some say not to use dpm over existing but most say its ok and reading through all that I can find I am still unsure of the way forward.
I have a new build concrete floor butting up to and at the same level as original pine floor boards that are on joists over an 18inch void that is supplied with air from airbricks, the new build first covered up but then maintained the air bricks via the brown waste pipes set in the concrete and entering the void where the old air bricks were - this is at the back of the house and there is also air bricks at the front
I will be fitting 18mmx 150mm engineered oak floor - floating I know I must use a DPM at the concrete part. I then plan to use 3mm foam underlay - the green one with barrier printed on one side throughout the rest of the lounge hallway dine room 40sq m
BUT my question is can I use that underlay on my existing floorboards or not as it does include a dpm within it. I don't want to use the white stuff as that is only 2mm.
I have looked into duralay duratex the one without dpm but still don't know how moisture can pas through that - or the white foam for that matter.
Just got back from nec homebuild show and Some say not to use dpm over existing but most say its ok and reading through all that I can find I am still unsure of the way forward.
I have a new build concrete floor butting up to and at the same level as original pine floor boards that are on joists over an 18inch void that is supplied with air from airbricks, the new build first covered up but then maintained the air bricks via the brown waste pipes set in the concrete and entering the void where the old air bricks were - this is at the back of the house and there is also air bricks at the front
I will be fitting 18mmx 150mm engineered oak floor - floating I know I must use a DPM at the concrete part. I then plan to use 3mm foam underlay - the green one with barrier printed on one side throughout the rest of the lounge hallway dine room 40sq m
BUT my question is can I use that underlay on my existing floorboards or not as it does include a dpm within it. I don't want to use the white stuff as that is only 2mm.
I have looked into duralay duratex the one without dpm but still don't know how moisture can pas through that - or the white foam for that matter.

