SPC flooring

[MariaD]

Hi all,

I’m planning to install SPC flooring tiles in my new build home and the SPC tiles I’d like to use are with built-in underlay. I’m wondering if I still need to lay down a separate roll of underlay underneath or similar, especially for moisture control and/or sound insulation both for concrete floor, which is downstairs and OBS panels, which are upstairs. 

I also would like to know if, to properly install SPC tiles on OBS panels, should this be smooth out?

 

I will attach pictures of both floors. 

 

Thanks in advance for any tips

[Nickfromwales]

Maybe good if you can post a link to the exact product in mind.   

[MariaD]

35 minutes ago, Nickfromwales said:

Maybe good if you can post a link to the exact product in mind.   

something like this: Beige Slate - Wood Innovations

[Nickfromwales]

The floors with OSB, TBH, are pretty bad. I'd lay a 6mm plywood over all of these, and then you should be fine to just lay the product straight on top. You may want better acoustic control for the first floor, so consider using this (LINK) for that. It'll also take out any minor defects / bumps and lumps.

 

For the concrete floors, I doubt you need sound insulation, just an EPS type of underlay (LINK) that you tape the joints with, and that will act as a moisture barrier.

 

You may want to use XPS insulation (LINK) to give better thermal insulation, which will also do the job of moisture barrier, if that floor is particularly cold. This can be bought in different thicknesses, so if you can get 10mm or more down, then the more you put the warmer the floor will be / feel. The thicker stuff will also help with lumps / bumps on the concrete floor too.

 

 

[MariaD]

24 minutes ago, Nickfromwales said:

The floors with OSB, TBH, are pretty bad. I'd lay a 6mm plywood over all of these, and then you should be fine to just lay the product straight on top. You may want better acoustic control for the first floor, so consider using this (LINK) for that. It'll also take out any minor defects / bumps and lumps.

 

For the concrete floors, I doubt you need sound insulation, just an EPS type of underlay (LINK) that you tape the joints with, and that will act as a moisture barrier.

 

You may want to use XPS insulation (LINK) to give better thermal insulation, which will also do the job of moisture barrier, if that floor is particularly cold. This can be bought in different thicknesses, so if you can get 10mm or more down, then the more you put the warmer the floor will be / feel. The thicker stuff will also help with lumps / bumps on the concrete floor too.

 

 

Thank you Nickfromwales :-).

[Nickfromwales]

9 minutes ago, MariaD said:

Thank you Nickfromwales :-).

Just stick an @ sign in the reply, and then the first letter of a members name you'd like to mention, and you can choose from the drop down list  

 

Other will comment when they pass through  

[MariaD]

@Nickfromwales Thanks again for your advice. Just to confirm, is the correct installation order for the upper floor: plywood boards over the OSB, followed by 3mm Acoustalay, then SPC tiles on top? Also, would you recommend going for 9mm plywood instead of 6mm for peace of mind, or would that be unnecessary?

[Nickfromwales]

2 hours ago, MariaD said:

@Nickfromwales Thanks again for your advice. Just to confirm, is the correct installation order for the upper floor: plywood boards over the OSB, followed by 3mm Acoustalay, then SPC tiles on top? Also, would you recommend going for 9mm plywood instead of 6mm for peace of mind, or would that be unnecessary?

Yes. That’s the order of events.
 

If you can fit the thicker plywood then the level of the floor will improve a little more, but in honesty even at 12mm the plywood will still just follow any undulations.

 

Prep work is always the main thing, and (as I am not there) my first thing to do would be to get the floor checked, as is, for high spots and remove those first; a metal paint scraper may suffice, but don’t go mad. Use a 2’ or 4’ spirit level and drag it over the floor in both directions and see if it catches or bumps over something, and remove.
 

The floor looks quite frayed from the pics so prob just needs a bit of a once over to check for lumps / splintered bits of the surface sticking up etc.

 

Next thing is to walk along each joist (you’ll see where the screws / nails are that hold the original boards down) and see if there’s any squeaks or creaks. Anywhere there’s an original fixing you can add a second if you can see movement. Don’t add any anywhere else as there may be pipes or cables   That would need another new thread here lol. 

 

When you screw the ply down you need screws set in every 150mm and all max 150mm apart like a grid (4.0 x 25mm wood screws for 6mm ply, or 30mm for 9mm ply) and the heads of the screws must be just slightly sunk into the face of the plywood. Like this.

 

The screw holes were filled and sanded back as that floor was a very thin B&Q type self adhesive ‘plank’, but for yours you can omit the filling as the composite won’t show them like thin LVT does.

 

In terms of the acoustic underlay, the better the underlay the quieter the foot traffic noise will be downstairs. Get advice from a local flooring outlet and buy the best one you can. Visit a few as some may just try to sell you dead stock, and gauge the advice / product. If unsure, ask here again.

 

You’ve got the skirting boards off so happy days, but using a multitool to perform undercuts at the door linings etc makes a good job great. YouTube vids will explain in pictures and words, so please do spend a morning watching how installers start, set out, and cut and then lay, and you’ll see what not to do to get it looking A1.

 

Enjoy ! 😊