What subfloor?

[Ben007]

Hello,

 

I just bought a house in Bedfordshire and took all the carpet out on the first floor. The floorboards are from around 1965 and were lifted a few times in places for wiring. Many are broken and the floor is in general very uneven due to the boards. I lifted some boards and the joists look good. They are appr. 38cm apart in the center.

I want yo lay bamboo parquet and need a smooth subfloor. I decided to replace the  floorboards in the 3 bedrooms and the hallway (appr. 33m2) which are appr 20mm thick. All boards are dry snd so are the joists

My questions:

1. Which material should I use?

- 18mm osb 3 t&g

-22mm plywood t&g

-22mm p5 t&g

 

Do I need a planning permission on can I just crack on?

 

2. When I lift the boards up, is it worth it to paint the floor joists? If so with what? I thought it might protect them.

 

3. If I use plywood boards, would you paint them with a varnish before installing the parquet?

 

Any help is much appreciated!

 

 

[SuperPav]

Welcome!

 

First floor (not ground floor) you don't need to paint anything. You also don't need planning permission.

 

Any of the T&G chipboard floors would do you fine, 22mm would be a bit more solid and what I'd choose, but wouldn't fix any deflection in the joists as such.

Depending on access, plywood might be annoying to get up there in full sheets (and probably overkill as you're not doing a bathroom).

The other option you might have (hard to tell from the photos) is to just overlay 6mm plywood over the existing floorboards if they're dry and structurally fine. You can then glue/nail the parquet as required. This would be cheaper and easier.

 

Only thing to be mindful of when fixing anything is make sure you know exactly where your pipes and cables are, it's surprisingly easy to hit one! 

 

 

If you're doing the ground floor then I'd recommend to rip up the floorboards, and insulate underneath them, and then replace with chipboard.

[Ben007]

Hey SuperPav,

 

Thank you for your great answer. I found 22mm tongue and groove plyboards that are 240cmx59cm. I will replace the upstairs bathroom subfloor in the next one or two years when I renovate it.

 

I am just wondering if it makes a big difference between the 22mm p5 and the 22mm plywood? 

 

The price being the obvious.

 

The weight might be another one?

 

 

Edited May 24, 2022 by Ben007