What board should be used when replacing Under floor boards replacement

[Taanya]

Hi,

I am trying to get Carpets replaced. Underneath the carpets floor boards that were initially used are 12mm thickness.

Now builders have said that they don’t do this thickness anymore since these were used in olden day houses.

My question is can the 12mm floor boards be replaced where necessary with Plywood’s ?

Can someone advise on that?

Don’t see why not. I replaced ours with all sorts. Generally thinner boards but lifted up underneath with thin wood. But then I screwed a thin layer of plywood (4mm) over the whole lot to get a perfect finish.