Creaky Floor

[RyanM]

Hi Guys,

Just moved in to a new house (built 2003), which was built by barratts, so obviously the quality isn't very good.

The floor at the bottom of the bed and the floor adjacent in the small bedroom creak like hell, to the point it disturbs our new born!

I've lifted the newly laid carpet, and the flooring is 2' x 7' plywood, and the creaky board goes under the wall from the big bedroom in to the small bedroom. You can also see a slight dip in to floor if you compare it to the skirting.

I bought some huge screws and a pipe/cable finder (so I didn't have any accident), and screwed loads of screws through the ply, in to the joists - this didn't do a thing! I also tried the talcum power trick, but obviously that did nothing as well.

I phoned a well known joiner in my area, who didn't really seem interest and said there was nothing I could do?!

Surely there is an answer to this, as we aren't getting much sleep with the newborn anyway, and the creaky floor is making things worse.

Could I circular saw the boards up, and install loads of extra noggins? Would this actually help? I believe the ply should be 18mm? What size wood would be required for the extra noggins?

I don't suppose there is a lot I can do about the sagging joists?


Any advice would be great, as I may need to DIY this.



Thanks a lot


Thanks a lot

 

[Deleted member 174758]

You can sister joists to strengthen them and take out dip, but one way to make any suspended floor more rigid is to install solid strutting between the joists (the uninitiated often refer to these, incorrectly, as noggins). I don't know if your boards are t&g or square edged, but I find it appalling that you need to do a job such as this on an almost new house. T&G boards or grooved edge boards with loose tongues should ideally be installed with the joints glued - and we always screw boards down - never nail them down (which seems to encourage squeakiness)

 

[RyanM]

Hi JobAbdKnock, thanks for the reply.

I did think solid strutting might have been the answer (noggins as I called them ) I didn't know about sister joists until now though. How long would a sister joist be? The whole length of the existing joist, or just a section around the poor area? How many solid struts are recommended to try to support the existing joists? Would you install these on the set of joists either side of the problem joist as well?

The boards which are down are just square edged, nailed down - As I said, I put a load more meaty screws in, but it didn't help.

It is a shame that quality is so poor now-a-days!

I think I might end up DIY'ing this, which I'm not looking forward too


Thanks a lot

 

[Deleted member 174758]

I've unfortunately seen a fair bit of poor practice with t&g chip floors. I don't like nailed floors because they all squeak eventually - we always screw ours down. Also it is common to see joints which aren't pulled up tightly enough or where no glue has been used on the tongues. Another common mistake is not supporting the short end joints on a joist - unsupported short end joints will always end up squeaking. If your joists aren't level then you'll struggle to fix a floor down properly; so you need to check the floor to find out where the dip is using a string line, spacer blocks and a traveller. A few millimetres plus or minus doesn't make much difference - 10mm on the other hand is a bit too much. You only need to sister the low joists but remember that the sistersing timbers will then be carrying your floor so you must not have big unsupported gaps. We generally solid strut at 2.5 to 3.5 metre centres and we go all the way across the floor. I can't see a couple of struts either side of a problem joist making enough of a difference - maybe 3 each side would e enough? If your boards are square edged you'll need to make sure that you pull the joints up tight as well and make sure any joints are supported on timbers, not just over a gap. Again I'm surprised that they didn't use t&g plywood or have edges grooved with a loose tongue (reduces tendency for the joints to to move), ideally with the joints glued

 

[RyanM]

Hi JobAndKnock,

Thanks for the reply again!

I saw another joiner I've used in the past and spoke to him about it, and he came round to have a look an hour later which I was pleased with.

He was surprised that there is no supporting wall below in the living room, as he said it's a large span to go across.

One of his suggestions was to cut the plaster/board away in the partition wall, where the sagging/creaking is worst, and use the wall timber to pull the sagging joist back up, and then install a recessed metal plate over a few joists to spread the load.

Does the sound plausible?




Cheers

 

[Deleted member 174758]

One of his suggestions was to cut the plaster/board away in the partition wall, where the sagging/creaking is worst, and use the wall timber to pull the sagging joist back up, and then install a recessed metal plate over a few joists to spread the load

I'm slightly dubious that you'll achieve all the success you want. The problem as I see it is that unless the wall was specifically made to be load bearing (i.e. with a doubled-up sole plate and header) it may well not be rigid enough to allow you to pull-up the low joist without itself being subjected to a lot of additional stress. The flooring should already have been fixed onto the joists (screwed) and then the wall frame fixed onto the floor, so what would you be gaining? In all probability that joist was installed incorrectly (if you have a slightly bowed joist it is always installed crown upwards so that the weight of the flooring pulls it down - not the other way round) and to lift it will require an Acrow prop and pads, or at the very least a timber "go bar" and some pads, but whatever you do it will always try to resume its' bowed down position once you remove that support. Is there no way that the joist could be sistered (to level the floor) and strutted conventionally? Sorry, but without seeing a job like this first hand it can be very difficult to give you a definitive answer

 

[RyanM]

Hi,
Thanks again for the reply.

To be honest, he did actually mention that the joist could be upside down as well! So at least he is thinking along the same line as you.

But, I do agree that the partition wall should be attached to the joist - although when I pulled the carpet back, you could see the floor boards run under the wall, so the partition wall may just be screwed (probably nailed in this house) to the floor board.

I will suggest sistering the joist again to him. I had never heard of this before, but reading more about it, I think it is the most sensible route to go down to be honest! (thanks for the suggestion). Just to confirm, would he run the sister joist the full length of the existing joist? I.e wall to wall? So he'd somehow have to get under the partition wall.



Thanks

 

[Deleted member 174758]

I do agree that the partition wall should be attached to the joist - although when I pulled the carpet back, you could see the floor boards run under the wall, so the partition wall may just be screwed (probably nailed in this house) to the floor board.

Nothing unusual in forming a stud wall on top of an existing (pre-installed) floor. You do get more rigidity if the wall sits on top of, and in line with, of an existing joist (if it isn't they should have installed solid struts below the wall between the joists) or if at right angles to the joists the sole plate is screwed (as opposed to nailed) through the floor boards and into the joists.

I will suggest sistering the joist again to him. I had never heard of this before, but reading more about it, I think it is the most sensible route to go down to be honest! (thanks for the suggestion). Just to confirm, would he run the sister joist the full length of the existing joist? I.e wall to wall? So he'd somehow have to get under the partition wall.

Ideally the sistering should run as near to wall to wall in a single as you can manage (there will be practical issues of how long a piece of timber you can install will be). It can be far easier to install longer timber from beneath, although that will mean partly reboarding the ceiling and skimming-in and so might be a less than attractive option. Whilst in an ideal world the sistering should be full length and the same depth as the original joist, in practice it is often necessary to reduce the depth of the tiimber by 10 to 15mm to be able to feed it into position. Practicality may also limit the length to as little as half the full length of the timber (but the longer the better), but providing this is near the centre you'll get extra rigidity. Make sure that the joists are tightly drilled (i.e. M10 bolt in 10mm hole - as square as possible, not tilted over at 45 degrees - this often requires an angle drill) and bolted together with star washers ("ninja stars") in the middle between the joist and sister and mudguard/penny washers on the outsides. Don't use coach bolts as they can spin round before you've finished tightening them up

 

[Andehh]

We had a terrible creak from where a floor disappeared under a stud/follow new build wall, our carpet guy drilled in 3-4 big screws at an angle to clamp the wall and floor together and it worked a treat! We got a hairline crack between skirting board and plasterboard wall, but some caulk quickly fixed that. Several months later still not creak at all.

Considered just hammering in some spacers between the two, and see if that reduces the movement/creak?

 

[RyanM]

Hi,

I did try hammering a wedge between the floor and underside of the wall, but it didnt help.

JobAndKnock, the guy came to do the job, and to save ripping the floor completely up (well at all). He acro'd the ceiling up from downstairs, then removed the skirting, cut some plasterboard away, and screwed some huge bolts (about 10") through the bottom of the wall, in to the joist below, put the skirting back on, and removed the acro.

This has fixed the problem with hardly no mess. I'm quite please with the repair, but wonder how long it will last? Indefinitely I hope.....



Thanks for the advice.