One of my daughters is rebuilding a conservatory, entirely herself, with great success. 

She has laid osb onto pir. Osb was a mistake as t and g chipboard would have been better, bit it is not changing.

So the concern is that foam vinyl will reflect the texture of the osb. Also that bits of osb may flake off once the vinyl is glued down.

Then of course the challenge of laying. She hasn't done carpets or vinyl before. I'm wondering if a thickish adhesive will help eg old fashioned evostik. Or a coat of unibond?

Any suggestions of the best way to stick it down? Skirting later will cover edge blips.

Can she add some hardboard over the OSB, and that will get rid of any worries and give a much better surface to adhere to.

I would go with 6mm plywood, which is the normal spec for prepping floor for Vinyl, this even goes if laying on chipboard - usually recommended to be screwed down at 150mm x 150mm squares and 100mm centres along the edges. As for adhesive, she could just order some spray vinyl adhesive like this random link: https://www.best4flooring.co.uk/vinyl-spray-adhesive.  Bostik also sell tubs of vinyl floor adhesive that might be a bit cheaper.

 

Last time I paid for an installer to do a vinyl floor for me he even filled and sanded over the screws and joins between plywood sheets and achieved a very good finish.

Edited February 6, 20242 yr by SimonD

With all these things I find it better to dry lay first. 

 

How was the OSB jointed or did the sheet cover they whole area? 

i think it will be fine over the actual osb but not the joins if the are not flush. shame she didnt use that expanding pva glue.

all of my vinyl flooring is suck down around the edges only with double sided tape, on the concrete flooring they sprayed some spray glue down first.

 

just push it into the edges with a blunt bolster chisel or some thin wood and it creases it, then cut with sharp knife.

16 minutes ago, Iceverge said:

did the sheet cover they whole area

No there are joins and it moves a fraction there. After filling it may be ok, and there will be a washing machine etc which will preload. 

She thinks she clicked the wrong item on the order and is cross with herself, hence hoping for a magic answer.

But I'm thinking best add another sheet glued and stapled everywhere. Then the taped edges may suffice too.

With these joins to  cover and strengthen the ply is favourite,  as hardboard may not be stiff enough,

 

Yes, it will be dry laid first.

Edited February 6, 20242 yr by saveasteading

There isn't 6mm to play with due to existing constraints. 3mm ply or 3.6mm ply seems expensive as not in stock as standard.

 

Not bad work for an Architect doing some practical.

Existing founds and slab retained, stick build above. Nobody else involved so far, but plumber and electrician will do their stuff.

Lift the OSB and replace with 2x thinner sheets of OSB or Ply. Staggered, glued and screwed. 

 

It's almost impossible to convince the a human to undo work they've completed but it's a vital thing to learn to do on course to becoming a true master builder like your daughter will be. 

 

 

 

Edited February 6, 20242 yr by Iceverge

https://www.wickes.co.uk/Wickes-General-Purpose-Hardboard-Sheet---3mm-x-1220mm-x-2440mm/p/110107

 

 

1 hour ago, Iceverge said:

It's almost impossible to convince the a human to undo work they've completed but it's a vital thing to learn to do on course to becoming a true master builder like your daughter will be. 

 

Sometimes it's not the one who's done the work. I've got so much criticism and scalding for redoing work that seems fine to others' eyes, not that I'm claiming to be a master builder by any stretch of the imagination, just want what I do to be right.

 

But back on topic:

 

Would a single T & G plywood subfloor replacement not suffice for replacement? That's what I would settle for if I didn't have the space for additional 6mm.

Edited February 6, 20242 yr by SimonD

Decision made. 6mm plywood does fit to the threshold level,  and is already obtained, being a standard product, So unibonding and screwing it on.

Then it will need a bit of latex at the threshold and be ready.

 

Thanks team.

Or you could have a floating LVT system on 2mm foam underlay. Easier and cheaperjob all round.

16 minutes ago, saveasteading said:

So unibonding and screwing it on

Drill clearance holes and countersink the heads, it will pull down better onto the adhesive.

8 hours ago, Conor said:

Or you could have a floating LVT system on 2mm foam underlay. Easier and cheaperjob all round.

If there's any vertical movement in the osb where it butts up (sounds like there is) then the lvt joints will break up over time.

1 hour ago, oliwoodings said:

any vertical movement in the osb where it butts up

No longer as it now has plywood overlapping the joints.