Squeaky bouncy loft floor - tips needed please

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We've had ongoing issues with the builder that did our loft conversion. One of these is the strange tongue and groove floor he has put down. It feels sticky to the touch, squeaks a lot, has large gaps in some areas, damages VERY easily and is almost crumbly in some edges. He put something down on a few areas to fix some crumbling bits and put a couple of screws in to reduce a squeak but said movement and noise is normal and would go once carpet down.

We've just had our fitted furniture done and the carpenter said there seemed to be a lot of bounce in the floor and also noted it felt sticky. We are due to have carpet fitted but I called builder with my concern and he said it is our fault. The loft was finished in January, painted in February and furniture has taken until now. Builder said it shouldn't have been without carpet for so long so there is nothing he can do now.

The fitted furniture has created some new loud creaks so we intend to put some of these extra screws down (https://www.screwfix.com/p/floor-ti...yf_Y_suc#product_additional_details_container).

We are also looking at using either talc or graphite lock lubricant to stop some of the boards rubbing. Is one f these better than the other?

Anything else we can do without taking floor up (this would wreck furniture and paint).
 
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Bounciness tends to make me think that the joists might be undersize, either that or the span exceeds about 16ft and your builder didn't install strutting between the joists to stiffen the floor. Neither of these issues can be resolved without lifting the floor

Squeaks and creaks can be a lot of things. For example sheet material floors which are nailed as opposed to screwed can squeak if the nails haven't quite hit the joists below, i.e. they've just grazed them. They can also be caused by careless nailing of stud frames where again the nails haven't pierced the timbers beneath properly. In general they also occur a lot more with flooring which has been gunned down (nailed down with a nail gun) rather than hand nailed (using oval nails or cut nails - for floor boards - or alternatively screwed and glued down - for sheet materials). A bit difficult to diagnose without a site visit, and not always then. Modern flooring should be something like T&G chipboard (which is correctly installed by glueing it to the joists then screwing it at 300mm centres - all tongue joints are glued - and this prevents squeaking and creaking), but decent quality flooring material isn't crumbly if adequately supported and properly installed.

The loft was finished in January, painted in February and furniture has taken until now. Builder said it shouldn't have been without carpet for so long so there is nothing he can do now.
You builder is BS-ing you. On large builds its' not unknown for the sub-floor (i.e. the plywood/chipboard) to go in and everything else to be finished, but the plot not to be occupied for several months for whatever reason (e.g. no access roads, no gas mains, etc). It does happen. I don't see Wimpey or Gleeson having these problems

TBH without seeing some photos it is difficult to say for sure, but I have the distinct impression that your builder maybe wears a tall hat and spurs
 
T&G chipboard is specifically designed to be glued to the joists and to have the tongues/grooves glued together. It is screwed to the joists at 300mm (or less) centres and all end joints either need to be over a joist or support by noggins. If your guys haven't done this then they screwed up the job.

They made mistakes with pipes etc and took it up and put back a few times. Looks screwed but possibly not enough.
Which probably means that they patched the floor, so are those patched areas where the creaks and squeaks are? If so they messed up with the make-good after sorting out the pipework. Really he should have checked and double checked his sub floor services before closing up the floor

Now we know that your sub-flooring is from a reputable supplier, these comments:

It... ...has large gaps in some areas, damages VERY easily and is almost crumbly in some edges. He put something down on a few areas to fix some crumbling bits and put a couple of screws in to reduce a squeak but said movement and noise is normal and would go once carpet down.
Indicate that he has done a poor job of installing the chipboard (and patching it - which if he were competent should have been minimal or zero). Egger chipboard doesn't crumble unless it has been badly treated and is unsupported - I've installed enough of the stuff to know that. As for "noise is normal and would go down once carpet down", that is complete and utter tosh - and I reckon he knows it. If the floor, and the joists beneath it have been properly installed there will be no noise, other than the sound of your footsteps as you walk across the floor.

It feels sticky to the touch...
And I think I know what the stickness might be: that sort of flooring gets delivered with a self-adhesive protective plastic film applied that is left in place whilst the various trades are working on the building to keep the floor clean (and protect it from the elements) and you pull it up at the end of the job after everything is cleared. It should leave a nice clean, ner perfect floor for the client. If it is left in situ for months after completion, particularly in warm weather, the adhesive can migrate to the chipboard making it sticky. Did he or you pull-up a clear, white or pale blue thin plastic protective film stuck to the surface of the floor at any time? Fortunately, the adhesive can often be lifted with a solvent such as white spirits or acetone, although it can take a bit of experimentation to find exactly which solvent works. Your builder should have been aware of this and removed the film before leaving the job.

Now I'm even more convinced that your builder doesn't understand carpentry and joinery, other than maybe installing a hitching rail near your back door during the job. Was he a brickie by any chance? (apologies to any brickies reading this, but my step brother is a bricky and left to his own devices this is exactly the sort of stuff he does - because he hasn't got enough of a grip on how the other trades do stuff)

The only solution I can offer is to add loads of screws (4.0 x 40mm or thereabouts) making sure that you hit the joists and not the services beneath. It may work, but it may not.
 
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Yes it had a film on but he removed that before all issues were resolved rather than right at last minute. My brother (quantity surveyor) came over before the Egger was laid and thought the joists looked good and no issues at that point. The builder himself did very little and it was his guys working but some were much better than others.

The big creaks are in a couple of areas lifted and replaced but one is just between 2 fitted chests of drawers and I think is because it's not glued.

It feels like the Egger is floated on top other than some screws and I assume this gives the bounce. The builders treated all the materials poorly and without care. We have chips in all new woodwork all over the place, nails left all over floor and some not hammered in where gun failed. This builder came highly recommended by various neighbours but I struggle to see why!

Would you say the screws in the link above are too long then? Also is the graphite powder pointless?
 
We have chips in all new woodwork all over the place, nails left all over floor and some not hammered in where gun failed.
You've just hit the nail on the head, so to speak. For a non-squeaky floor you absolutely must glue the boards to the joists, glue the tongues and screw the floor down as well NOT NAIL IT. This may seem a bit belt and braces, but is actually what Egger recommends in their technical spec sheets (AFAIK available online) - they actually go further than that and specify their own flooring glue, which is a PU (polyurethane) glue with what appears to be a solids filler which is designed to fill any gaps in joints and further reduce squeaking. The top protective film also greatly reduces the possibility of glue squeeze-out sticking to the floor surface.

Please bear in mind that I am trying to diagnose this over the 'net, without actually seeing the job first hand. However, in terms of squeak, your biggest problem is probably that the floor has been nailed rather than screwed (from what you say). Nails, particularly if they are plainshanksk as opposed to ring shanks, can partially pull out (especially on bouncy floors) leading to both the nails and joints squeaking. TBH I think I'd look to screwing the floor to the joists first, before trying the graphite. For 18mm floors we use something like 4.0 × 40mm to 4.5 x 50mm chipboard or flooring screws and the heads need to be sunk flush, so you may need to pre-pilot and countersink the holes. At 300mm screw centres (distance apart) on standard 400mm spaced joists you will need 35 screws per sheet. I think under the circumstances I might consider going to 150mm centres on the worst boards. This doesn't guarantee a complete cure - the only way to do that is to lift the floor and relay it properly

Despite your recommends it does seem your builder has done a poor job on the floor
 
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You've just hit the nail on the head, so to speak. For a non-squeaky floor you absolutely must glue the boards to the joists, glue the tongues and screw the floor down as well NOT NAIL IT. This may seem a bit belt and braces, but is actually what Egger recommend in their technical spec sheets (AFAIK available on line) - they actually go further than that and specify their own flooring glue, which is a PU (polyurethane) glue with a solids filler which is designed to fill any gaps in joints and further reduce squeaking. They top protective film also greatly reduces the possibility of glue squeeze out sticking to the floor surface.

Please bear in mind that I am trying to diagnose this over the 'net, without actually seeing the job first hand. However, in terms of squeak your biggest problem is probably that the floor has been nailed rather than screwed (from what you say). Nails, particularly if they are plain shank as opposed to ring shank, can partially pull out (esoecially on bouncy floors) leading to both the nails and joints squeaking. TBH I think I'd look to screwing the floor to the joists first, before trying the graphite. For 18mm floors we use something like 4.0 × 40mm to 4.5 x 50mm chipboard or flooring screws and the heads need to be sunk flush, so you may need to pre pilot and countersink the holes. At 300mm screw centres (distance apart) on standard 400mm spaced joists you will need 35 screws per sheet. I think under the circumstances i might consider going to 150mm centres on the.worst boards. This doesn'y guarantee a complete cure - yhe only way to do that is to lift the floor and relay it properly

Despite your recommends it does seem your builder has done a poor job of the floor
Reading your post I got to the part with 35 screws per sheet and gasped. We have 6 screws/nails on average per sheet! Probably not the right type of screw where it's a screw either. I'm guessing this fact explains a lot of the bounce feeling!
 
Reading your post I got to the part with 35 screws per sheet and gasped. We have 6 screws/nails on average per sheet! Probably not the right type of screw where it's a screw either. I'm guessing this fact explains a lot of the bounce feeling!
If you don't have enough screws the chipboard can lift (hence some of the creaking and cracking sounds) and the T&G joints around the edges of the boards will also tend to move, leading to more noises. The lack of screws may also be responsible for the bounciness, although I still feel that is as likely to be a joist related issue. At the very least you need to screw that floor down fully; at least then you'll get a better idea of where any other problems (if any) really are. Were it mine, I'd probably lift the floor, deal with the strutting (if required) then and glue it-down properly (i.e. with all the board ends supported, T&G joints glued and pulled-up tight, sufficient screws, etc), but I accept that I'm a joiner so a job such as that holds no fears for me

BTW if you think that 35 screws is mind-blowing, when you overlay (normally old) flooring with 6 to 12mm thick plywood to level-out the surface it's normal to screw it down at around 150mm centres over the entire sheet - or about 150 screws/sheet - whilst the nailing patterns for glued and nailed diaphragm floors, as used in some public buildings, can be in the order of 400 to 1000 screws/ring nails per sheet depending on the spec.
 
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