Plywood underlay over timber for vinyl flooring

[klamity]

Hi, 

I'm looking to set up our side room as a nursery and the current timber subfloor has gaps between the planks. I was thinking about laying some plywood over the top to cover the gaps/stop the draft coming through and then adding a vinyl roll over the top. Likely adding a vapor barrier in between as well. 

The current planks are 20mm. Should/can I use 7mm or 9mm plywood with these: 

https://www.bunnings.com.au/paslode-25-x-2-0mm-500g-bright-steel-annular-underlay-nails-650-pack_p23... 

Or does Bunnings sell 20mm underlay nails like this if I wanted to use 7mm plywood? I wanted to avoid going any thicker with the ply as that would mean the flooring will be higher than the rest of the house which is not ideal. 

timber floors

Will I need to fill these holes with anything particular? 

Any suggestions and recommendations would be appreciated. 

Thanks!

[MitchellMc]

Welcome to the Bunnings Workshop community @klamity. It's sensational to have you join us, and many thanks for your question about laying vinyl flooring.

Have you considered using Hybrid Vinyl Planks instead of vinyl roll? The benefit would be that you wouldn't require a vapour barrier, no need to lay plywood sheeting or nail into the floor, and as they lock together, will prevent drafts from entering through the timber floorboards. The vinyl planks are a floating system, and you could just get a few packs and start laying them. They'll also look and feel much nicer than vinyl roll. Here's a helpful step-by-step guide: How to lay vinyl plank flooring.

By the time you purchase the vinyl roll and plywood, you'll be close to 3/4 of the price of the planks. Vinyl sheeting also needs to be glued down to stop bunching. Once you add the cost of glue and think about your time, it would be worth upgrading to the planks.

In answer to your question, those nails would be fine for securely either the 7mm or 9mm plywood sheet. I don't believe you'd need to fill the hole as the plywood sheet would cover it sufficiently.

Please let me know if you need further information or assistance.

Mitchell

[klamity]

Hi Mitchell,

Thanks for the reply. Hybrid planks were considered but the boss has gone with a vinyl roll (already purchased), so unfortunately that's what we have to play with. 

I've been told Masonite could be a good option instead of plywood. Given my timber boards are 20mm and the Masonite is 4.8/5mm - would it still be compatible to use the 25mm underlay nails I previously mentioned or should I go with something shorter to fix the sheeting down? Also, is there much difference between Masonite standard vs underlay other than the thickness?   

Thanks. 

[MitchellMc]

@klamity,

25mm nails will slightly penetrate the underside of your 20mm floorboards if you're using 4.8mm Masonite sheets. They'll be fine for the 5mm underlay, though.

I'd recommend Masonite over plywood as it will be much smoother. The Masonite underlay has a perfectly smooth and even finish ensuring no defects are seen through your vinyl flooring. There are not a whole heap of differences between the non-underlay version. However, for a couple of extra dollars between the 1220 x 915mm 5mm Masonite Underlay and 1220 x 915mm 4.8mm Masonite Standard, I'd recommend the underlay version.

Mitchell

[klamity]

Thanks mate - glad I got in touch!