Floor edges visible through karndean

[drpepe]

To update this, the builders have spent a couple of days lifting tiles across the floor and mechanically fixing the chipboard down into the slab
ie. screwing the edges of each board down a few mm.

This has helped - a lot of the joints are barely perceptible under foot/hand except when the sunlight comes in either direction (windows are East/West). However there are joints that are still very obvious to the eye/hand/straight edge. Also - robustness - how long til the screws go pop?

The reason I am treading carefully (trying to be fair), is that we are reusing the slab footprint from an old conservatory, so there is minimal room for manoeuvre depth-wise:
ie.
*concrete slab
*small depth of screed to level
*insulation (only 20mm - the original plan was 70mm based on a trial hole, but the slab was higher by 40+mm at the other side of the room. The insulation was OK'd by local BC:'fit what you can under there')
*edit: DPM under chipboard
*chipboard floor (18mm)
*latex
*karndean

Options:
1. Retrofitting 6mm ply on top of chipboard to meet mfctr specifications- but this would not allow us to fit the karndean under the sliding door (see pic, there is no clearance) Or is there some clever detailing that could be done next to the door?
2. Rip it all up down to the slab, replace using say 12mm insulation to gain room for ply
3. Accept the floor as is, ask for discount with threat of paying nothing for the flooring if they don't play ball?
4. ?

I am sure the builder won't entertain 1 & 2, but I could ask always a local fitter to quote to replace properly to mfctr guidelines and get them to do it (deduct from builders bill).

 

[dazlight]

You be best getting this post on the flooring forum

 

[Deleted member 174758]

What centres is the chipboard fixed down at? 150mm? 300mm? The floorers I've worked with (I'm a joiner, mostly commercial) always insist on the sub-floor being thoroughly fixed down with a guaranteed DPM beneath it, and even then they always put a thin screed over the top. I'm concerned that you think the chipboard might lift. This makes me wonder about whether or not there is an effective DPM under the screed, or if the screed isn't truly dry and is still releasing moisture (screed takes a long time to dry out), and/or that there may not be sufficient screws holding it down. (BTW 150mm centres = 153 screws per 8 x 4ft sheet)

What does the manufacturer have to say about using a single skin of, say, 18mm plywood as a sub-floor? So I wonder about the possibility of taking the chipboard out and substituting 18mm ply, plugged and screwed at 150mm centres (a lot of work) then a thin skim of levelling compound over the top before laying the finished flooring. The skim would take out the joints, screw heads, etc

If you overclad with 4mm or 6mm plywood this will need to be fixed on 150mm centres and again given a thin skim of levelling compound, too. The idea, I thought, was to get a floor surface as flat as a billiard table for LVTs. Certainly when laying sub-floors in shops, etc the floorers won't accept half neasures

What is the sliding door made from? If it is timber a decent joiner should be able to alter the door. Most of the sliding doors I've come across are suspended from a track at the top with mimimal guides at the bottom (perhaps only a couple of guide blocks, rollers or a peg which runs in a channel hidden in the bottom edge of the door), so they can be altered. The ones which can be a bit more of an issue are doors with connected opening mechanisms (i.e where when you open one door the other opens simultaneously) and those which disappear into pockets in the wall. Post a photo of the track at the bottom and someone may be able to answer that query for you.

 

[drpepe]

What centres is the chipboard fixed down at? 150mm? 300mm? The floorers I've worked with (I'm a joiner, mostly commercial) always insist on the sub-floor being thoroughly fixed down with a guaranteed DPM beneath it, and even then they always put a thin screed over the top. I'm concerned that you think the chipboard might lift. This makes me wonder about whether or not there is an effective DPM under the screed, or if the screed isn't truly dry and is still releasing moisture (screed takes a long time to dry out), and/or that there may not be sufficient screws holding it down. (BTW 150mm centres = 153 screws per 8 x 4ft sheet)

What does the manufacturer have to say about using a single skin of, say, 18mm plywood as a sub-floor? So I wonder about the possibility of taking the chipboard out and substituting 18mm ply, plugged and screwed at 150mm centres (a lot of work) then a thin skim of levelling compound over the top before laying the finished flooring. The skim would take out the joints, screw heads, etc

If you overclad with 4mm or 6mm plywood this will need to be fixed on 150mm centres and again given a thin skim of levelling compound, too. The idea, I thought, was to get a floor surface as flat as a billiard table for LVTs. Certainly when laying sub-floors in shops, etc the floorers won't accept half neasures

What is the sliding door made from? If it is timber a decent joiner should be able to alter the door. Most of the sliding doors I've come across are suspended from a track at the top with mimimal guides at the bottom (perhaps only a couple of guide blocks, rollers or a peg which runs in a channel hidden in the bottom edge of the door), so they can be altered. The ones which can be a bit more of an issue are doors with connected opening mechanisms (i.e where when you open one door the other opens simultaneously) and those which disappear into pockets in the wall. Post a photo of the track at the bottom and someone may be able to answer that query for you.

Thanks for the reply. Regarding the DPM, apols there is one under the chipboard apparently - I have edited my post above

The floor is certainly not billiard table flat! From the moment I mentioned it builders have been saying you can't expect 100% perfection ... The mfctr states that any wood subfloors should be overlaid with "a 1/4” (5.5 mm) flooring grade plywood** fixed at maximum 6” (150 mm) centres. Plywood joints should be smoothed over using skim coat/patch or alternatively a full coat of a fibre reinforced smoothing compound. "

I am concerned about the boards lifting because they've retrospectively lifted *some* tiles and screwed down *some boards* into the slab. I have no idea what centres the used for the screws, but I imagine it wasn't done as you described.

Sliding door is white aluminum - haven;'t got a photo right now but it is a Smart Systems Visoglide Plus.

 

[Deleted member 174758]

The floor is certainly not billiard table flat! From the moment I mentioned it builders have been saying you can't expect 100% perfection ...

In that case I must work for and with people who are genii... (believe me, they aren't) We consistently install joisted floors to 2mm +/-, or less (which is nothing special) and if you can't flatten a floor with levelling compound on top of plywood/chipboard, then nothing else you do will be right, either. A 6ft level and an obtuse light will show you where any crowns in the screed are and those can be taken down with a brickie's rubbing brick (an abrasive stone with a handle on top) or a concrete grinder. The ply or chipboard over the screed then takes out the greatest part of the dips, leaving only a small amount of levelling compound to deal with the rest. Again a 6ft level and a low angle light can be used to check where any remaining dips are. This is not rocket science, and in these days of laser levels, 6ft spirit levels and levelling compounds it isn't difficult

150mm centres for sub flooring is pretty much standard these days and your builder should know this.

Sliding door is white aluminum - haven;'t got a photo right now but it is a Smart Systems Visoglide PlPlus.

I'm not familiar with those, and in any case I am on my mobile at the moment, but when I get home I'll look it up and if nobody else answers I'll give you my two pennorth, for what it's worth. I have seen ally installers resize doors on site, so it may be doable

 

[Deleted member 174758]

I'm not familiar with those, and in any case I am on my mobile at the moment, but when I get home I'll look it up and if nobody else answers I'll give you my two pennorth, for what it's worth. I have seen ally installers resize doors on site, so it may be doable

OK, so I had a look at the cross sectional drawings and data on the manufacturer's website and I think it's no go in terms of resizing stuff. What I still don't understand is why your builder thought he could install the door and bodge the floor afterwards.

What you can't allow him to do is leave you with a floor which is higher than the sliding door threshold - that woud be a trip risk and is therefore unacceptable

FWIW I don't think you are being unreasonable expecting him to deliver an acceptably flat floor (note that I am not saying perfect, but it needs to look right), so it's up to him to sort it out