Floor levelling & LVT again

[Spinny]

So I have most of my LVT down now only another 15 sqm to do.

 

However as I feared there is another undulation/raised area within the floor leveller applied on the remaining floor area. The bulk of the floor area is between 0mm and +3mm of target. However there is a ridge/raised area where part of the floor rises to +5mm or +5.5mm and then back down again. Rising from say an acceptable +2-3mm to the peak of +5.5mm and back down to +2mm again over about a 1.4m distance. 500mm rising from +2mm to +5mm, then flatish for 400mm, thenback down to +2mm over 500mm. You can rock a spirit level on the ridge and measure up to a 3-5mm gap under the end of a 1.8m spirit level.

 

There was 1 other smaller area on the floor now laid that had a 'hill' and I asked for it to be reduced as thet said it could be sanded down. However the sanding/grinding process did leave some fine ridges in the floor surface - basically like marks from a sanding/grinding disc. And now the LVT has been layed over that area, these marking suprisingly show through. When viewed into the light at the right angle you can see the markings in the LVT itself, which seems to have conformed itself to any lack of total smoothness in the floor surface.

 

So should I not have my other 'hill' sanded down, as 'messing with it' may reduce the hill/ridge, but end up with the floor perhaps looking worse because the working marks will show through in the LVT surface ? Should I live with a lack of levelness in a decently smooth surface - or risk having a flatter but unsmooth surface by having the flooring contractor work on it ?

 

See photos...

The hill is where the darker pour area is on the floor - now with levels marked on tape by me.

 

The closer photo of the other LVT laid floor area shows how you can see small arcs in the LVT in glancing light from the open door way. This is where the other high spot was sanded/ground down.

 

 

Edited Wednesday at 16:29 by Spinny

[Nickfromwales]

@Spinny

 

I'd suggest copying this to the existing thread on this 'journey', as it would have made much more sense there and have greater context.

 

If you want to do that, I can then hide this one .

[Gus Potter]

14 hours ago, Spinny said:

However as I feared there is another undulation/raised area within the floor leveller applied on the remaining floor area. The bulk of the floor area is between 0mm and +3mm of target. However there is a ridge/raised area where part of the floor rises to +5mm or +5.5mm and then back down again. Rising from say an acceptable +2-3mm to the peak of +5.5mm and back down to +2mm again over about a 1.4m distance. 500mm rising from +2mm to +5mm, then flatish for 400mm, thenback down to +2mm over 500mm. You can rock a spirit level on the ridge and measure up to a 3-5mm gap under the end of a 1.8m spirit level.

I appreciate your desire for level and diligence. 

 

Have you considered. If you have an existing house. How level and undulating all the other floors are? If a new house then it is going to take time to bed in, settle.

 

To provide a bit of context. Often as an SE I'll start by designing a house to settle no more differentially by 25mm! Then refine depending on the finishes and how tolerant the structural frame is going to be in terms of differential settlement.  A Swedish log cabin might shrink by 75 - 100mm!

 

I would give the floors you have laid so far a "walk over test" not by you, but by visitors. Ask them if they notice much level or issues with flatness. 

 

Glancing light is always going to show up even tiny changes. This is building, not eye surgery!

 

 

[Mr Punter]

I have an early Victorian rental and the plinth in the kitchen is out by 50mm over 1200mm.  Oddly it is not that noticeable to walk on.

[saveasteading]

8 hours ago, Mr Punter said:

Oddly it is not that noticeable to walk on.

We don't notice the small rises and falls and especially not consistent slopes.

Eg we have a dreadfully poorly screeded room with 17mm variance from one corner to the opposite. ( v Big room)

You cannot feel it in walking.

 

The tiler has dealt with it skillfully with double buttering which also loses the dips and ripples.

But: it is visible and a pain in fixing skirtings.

If the floor was thin LVT then it would follow the curves and show every ripple and I'd worry about it not even lying in straight lines.

If the floor was thin laminate I'd worry about ridges and hollows being bridged and bouncing.

 

What am I saying? 1. It depends what floor you are laying. Appearance may be more of an issue than performance or final shape.

2. The screeders' work is awful and next time I'd ask very rigorous questions about method and control. Because of seeing it done well once, I assumed a level of competence which was not there.

 

[saveasteading]

On 20/08/2026 at 08:38, saveasteading said:

cannot feel it in walking.

Here's a tip, no charge.

 

To assess if there is a slope, without equipment., walk a straight line with a comfortable gait. Then reverse and walk the same line back. That at a minimum tells you if there is a difference, and which way. I'd say this detects say 2% or more.

 

Whether that difference is significant is another matter.

[Spinny]

I have the contractor coming tomorrow to take a look and give me the benefit of their experience. Very likely the inevitable advice will be to do nothing and just floor over it of course. But any more thoughts on this appreciated.

 

When the builders poured the original underlying concrete slab they said it would be level within 6mm - they achieved about 30mm variation and 10mm higher than target. When the flooring people levelled it the standard for thin-layer flooring is SR1 or <3mm over 2m but haven't fully achieved it.

 

Maybe it is best left as is ? I can perhaps find a carpenter to cut one table leg shorter if it proves a problem 🙃

 

I get the comment about floors generally, but when new they ought to be very close to level and this should be achievable with the otherwise somewhat euphemistically named 'levelling compound'. 

 

What have others achieved on their build with hard floors ? Anyone else that sees subfloor flaws showing through LVT ?

The guy laying it uses a very thin layer of adhesive and rolls it down hard - I had imagined that rather like ceramic tile laying that the adhesive bed could be somewhat varied to counter subfloor flaws ?

 

Quote

The individual segments of the James Webb Telescope's primary mirror are polished smooth to an accuracy of roughly 20 nanometers—about 10,000 times thinner than a human hair.

 

[saveasteading]

30 minutes ago, Spinny said:

should be achievable

It is apparent that not only are the necessary skills in short supply, but so is knowledge.

I've been 7 years or so out of the industry. Things are much worse, or maybe it needs a lot more project management and toughness.

Our floor issues are because the 'specialist' screeder sent in one guy to lay the insulation and he did NOT like supervision or questions, at which point he couldn't speak English. Fast but rough.

Then next day the same guy was laying ufh pipes  very quickly and quite well.

Then a different gang poured the screed and just moved it around...no level control.

Again, no Interest in discussing control of levels: other than to say ' of course, this is what we do'.

I never saw the boss unless one of them really was but was feigning just bring a worker.

 

Next time, I would have a very serious discussion  beforehand. If it added 2 man days and some screed it would be worth the cost.

[Nickfromwales]

23 minutes ago, saveasteading said:

It is apparent that not only are the necessary skills in short supply, but so is knowledge.

I've been 7 years or so out of the industry. Things are much worse, or maybe it needs a lot more project management and toughness.

Our floor issues are because the 'specialist' screeder sent in one guy to lay the insulation and he did NOT like supervision or questions, at which point he couldn't speak English. Fast but rough.

Then next day the same guy was laying ufh pipes  very quickly and quite well.

Then a different gang poured the screed and just moved it around...no level control.

Again, no Interest in discussing control of levels: other than to say ' of course, this is what we do'.

I never saw the boss unless one of them really was but was feigning just bring a worker.

 

Next time, I would have a very serious discussion  beforehand. If it added 2 man days and some screed it would be worth the cost.

Next time, let me know and I'll send you contact details for my chap. He is shit hot.

 

He asks where the key points are, sets out pads off a laser, then joins the dots (pads) for a flawless result; he literally bends the floors to get what I want, where necessary, and it's totally unnoticeable. One job was 10mm to 90mm undulation, and he walked through it perfectly; only issue was at less than 25/30mm he insisted on a specialist primer so the thinner areas wouldn't delaminate. Which they didn't. I went back to the job some 7 years later, and the tiled floor was still A1.

[scottishjohn]

this will be why my guys insisted on self levelling then grinding it  and checking again the moisture content  before fitting the LVT

the lvt will only be about 3mm thick --so will follow contours if there are any 

and as with most things the the preparation is the important bit to get a perfect job