Deep rubbing groaning grating noise from T&G chipboard floor

[enjoylife]

Hi all,

Got new t&g chipboard floorboards (18mm) flooring put down in a new loft floor. I don’t believe the builders properly glued everything as they should so it was making squeaks / popping noises a lot. After couple of builder visits and additional screws, my own attempts at adding many more screws across all joists and after finding supporting noggins, it’s a lot better.

However, there is just this one main deep rubbing / groaning / grating noise (not the usual squeak/popping noise) coming from near the short edge of one of the floorboards which is making me mad. The area in question is in middle of the room where short edge of two floorboards meet. There are overlapping joists exactly under this area sitting on an internal wall. One of these joists sit exactly under the short edge joint (supporting each board with roughly half its width). The other overlapping joist is on the inside side of the problem side next to the short edge.

I have tried adding lots of additional screws on both joists through floorboards, even added pu expanding glue in some screw holes in this area and screwed it back (it was suggested this can help with and minor gaps between floorboards and joists). But no improvement to the noise at all. The noise is deep rubbing, groaning, grating which happen when I step near or on the short edge of the board and then get sort of a reverse noise when I step back (in see saw king motion).

My last theory is sound maybe coming from the t&g joint itself on short edge rubbing deep inside. Talcum powder hasn’t helped as joint seems too tight for anything to go in. Any help / suggestions would be greatly appreciated.

Desperate for some help as I am running out of time before carpet gets put on in couple of days time.

 

[Wayners]

Loft, you just put a few screws around edges so it can all come up for access.
Also loft joist flex as not ment to be a floor.

 

[enjoylife]

Loft, you just put a few screws around edges so it can all come up for access.
Also loft joist flex as not ment to be a floor.

Sorry should have mentioned this is part of a loft attic conversation with new joists / properly supported floor etc. (it’s not a standard temporary access storage floor).

 

[Wayners]

Watered down PVA in joint and walk on to work in. Few more screws.. I think you've done all you can.

I've got this Idea. Cut a 5mm groove along joint and fill with dry flex resin. Don't knowing if that would work?

 

[enjoylife]

Watered down PVA in joint and walk on to work in. Few more screws.. I think you've done all you can.

I've got this Idea. Cut a 5mm groove along joint and fill with dry flex resin. Don't knowing if that would work?

In two mind whether to use watered down pva glue or not. Have heard it works well to stop squeaky and fill gaps but not too sure about very tightly coupled joints like me. There is a risk apparently it may swell the joint and make things worse with noise which I really cannot afford to happen. Hence, on the fence with it.

Screws have put more than enough. Think there maybe a small difference between height of the two overlapping joints causing the stress in the joint and creating deep groaning noise.

Not sure about cutting a grove at the joint. Isn’t there the t&g joint is and not sure what interfering with that will mean.

 

[Wayners]

You can drill holes and infect no nails to pack.
I say no nails as it hard vs other mastics

 

[enjoylife]

You can drill holes and infect no nails to pack.
I say no nails as it hard vs other mastics

Yes thinking of drilling shallow holes at the short edge and inject some dry lubricant first (graphite powder) to try it out.

 

[foxhole]

Cut holes with hole saw on joint , this allows you to place a timber below to reinforce joint.

 

[enjoylife]

Cut holes with hole saw on joint , this allows you to place a timber below to reinforce joint.

As I mentioned in my original post, there is already a joist right under the short edge joint and it supports both adjacent boards (half joist width under each board).

 

[Scally-Ho]

Having read through this topic, IMO the flooring would benefit from an intermediate support close too or right under the section that is emitting the noise. What about a length of 3" x 2" stiffening under that section and extending a good 3ft in both directions screwed into from the chipboard above.

 

[enjoylife]

Having read through this topic, IMO the flooring would benefit from an intermediate support close too or right under the section that is emitting the noise. What about a length of 3" x 2" stiffening under that section and extending a good 3ft in both directions screwed into from the chipboard above.

Unfortunately no access to joists from below (sealed ceilings below) and don’t want to cut and take newly laid t&g boards out. So stuck with trying to somehow fix it from the top.

 

[foxhole]

As I mentioned in my original post, there is already a joist right under the short edge joint and it supports both adjacent boards (half joist width under each board).

If there is movement then it can’t be supporting correctly .

 

[robinbanks]

Agree with FH; if you e got a TnG short edge that has each side perfectly landing on half a joist, and both sides are glued and screwed to the joist, there won't be any movement. If it's still groaning, could it be the joist that is noisy rather than the floor?

When you say you used lots more screws, exactly which screws? (Take a picture of one of the screws you've used)

 

[enjoylife]

Agree with FH; if you e got a TnG short edge that has each side perfectly landing on half a joist, and both sides are glued and screwed to the joist, there won't be any movement. If it's still groaning, could it be the joist that is noisy rather than the floor?

When you say you used lots more screws, exactly which screws? (Take a picture of one of the screws you've used)

The movement in t&g seems to be due to overlapping joists right in that area. One of those joists (inside one) seems to be bit higher (few mm) than the one right under the short edge joint. So this is probably causing uneven support putting stress at the joint. I found this when drilled holes to inject pu glue to fill any gaps between board and joist. Regarding screws, I have 4 x 50mm screws, the ones with bit of plain shaft at the top to avoid jacking.