Bouncy floor/joists

[jamie87]

Hi all just looking for some opinions on my problem. I have late 1800's end terraced house.

The floor in the bedroom is quite bouncy and as im decorating the room i thought i'd investigate why. I was hoping that it would be the end of the joists needed supporting or the mortar had crumbled underneath them but all this seems fine.

The bounce is worse the further into the middle of the room i go and is a lot worse on the joist which ran across the front of the hearth. The majority of the boards on this joist all squeek and move slightly too where they are fixed as though they have pulled away from the joist.

I have now removed the hearth. This was sat on a frame made of floorboards which was fastened to the worse offending joist and then resting onto the joist closest to the chimney breast.

Could this joist be bouncy because its been taking the weight of this joist for all this time or should i be looking further into it?

Sorry it is a bit long winded and thanks for taking the time to read/reply

 

[tony1851]

It's probably just that the joists are small by modern standards. Your floor won't collapse.

 

[jamie87]

Thanks.

The joist are 2.5 inch x 7 inch and spaced around 18 inch. The length they run is approx 3.5 metres

 

[RonnyRaygun]

Thanks.

The joist are 2.5 inch x 7 inch and spaced around 18 inch. The length they run is approx 3.5 metres

Doesn't sound unreasonable. Maybe a lack of noggins or struts...

 

[pinenot]

Do the joists run in line or at right angle to the hearth/fireplace and if the later how are they supported?...pinenot

 

[jamie87]

Thanks.

The joist are 2.5 inch x 7 inch and spaced around 18 inch. The length they run is approx 3.5 metres

Doesn't sound unreasonable. Maybe a lack of noggins or struts...

By noggins or struts do you mean wood that go between the joists? If so then there is none that i can see throughout the room

 

[jamie87]

Do the joists run in line or at right angle to the hearth/fireplace and if the later how are they supported?...pinenot

They run in line with the hearth and this seems to be the bounciest part where the hearth was resting on this joist although it does it slightly in other places

 

[^woody^]

 

[pinenot]

[quote/] They run in line with the hearth and this seems to be the bounciest part where the hearth was resting on this joist although it does it slightly in other places[/quote]

It sounds like the noggin recommendation should do the trick, means lifting the floorboards though...pinenot

 

[jamie87]

[quote/] They run in line with the hearth and this seems to be the bounciest part where the hearth was resting on this joist although it does it slightly in other places

It sounds like the noggin recommendation should do the trick, means lifting the floorboards though...pinenot[/quote]

Thanks. So what size timber should i use? And how often should i put them in it etc?

Room is approx 3m x 3m

 

[pinenot]

Certainly across the full central runs, full size noggins (same depth as joists) perhaps a we bit clearance from the ceiling below, cut square and just at full size, knock them in and either skew nail the ones with no open joists to allow full nailing or stagger the run of noggins. You could also put some in where ever else you think, just make sure it's at least two noggins, thereby binding three joists together...pinenot

 

[jamie87]

Certainly across the full central runs, full size noggins (same depth as joists) perhaps a we bit clearance from the ceiling below, cut square and just at full size, knock them in and either skew nail the ones with no open joists to allow full nailing or stagger the run of noggins. You could also put some in where ever else you think, just make sure it's at least two noggins, thereby binding three joists together...pinenot

Great stuff thanks for the help, will give this a try