New Build joists

[Kton2002]

Hi All,

Moved into a new house at the end of Jan. Had some cracking noises from where the stud timber walls upstairs were meeting the floor, which were mostly resolved by the builder by packing under them. However i am a little concerned re the deflection in the joists in the main bedroom, picture attached of the kitchen downstairs which i took before it was all plaster boarded. The large wardrobe we have put in the bedroom above moves slightly when you walk past it, as do a chest of draws (although they are close to the wall so less likely the joists and more likely just movement from the carpet). Now i assume that the joists are spaced at 600mm, but wanted to know if anyone knows if this is correct. Thanks in advance

 

[Deleted member 174758]

Now i assume that the joists are spaced at 600mm, but wanted to know if anyone knows if this is correct

Surely you mean 400mm

 

[Kton2002]

I thought they were spaced according to the size of the joist itself and the span? I think they have been spaced at 600mm

 

[foxhole]

What’s the span . ? Need to be less than around 3.5 m to use that spacing . Personally would never use 600mm spacing on a joist.

 

[Kton2002]

Yep span is around 3.5 / 3.6 metres

 

[geraldthehamster]

Look at the blockwork - the joists are at 600 centres

 

[Kton2002]

Thanks - i actually on reflection think it is just vibration causing the wardrobe doors to shake a little as i walk past them. As even just repidly pressing the carpet up and down near the base of the wardrobe has a similar affect

 

[geraldthehamster]

The joists may be within span, but is the chipboard flooring? If it's 22mm it is; if it's 18mm, it isn't.

 

[Kton2002]

It is caberdek norbord, but not sure how i can tell the depth

 

[John D v2.0]

where is the blocking/struts? Is it not needed with those engineered joists?

 

[catlad]

Chipboard floor & 600 centres = wobbly

 

[Leofric]

If it is a new house put your concerns in writing to the builder and keep a copy.

 

[Kton2002]

They came back and took the skirting off, and packed under it which helped remove the cracking noises. But it has returned again. It is apparently where the stud wall meets the chipboard flooring. It is definitely 22mm chipboard on 600mm centre joists. Not sure how much noise is acceptable with a timer framed wall and chipboard flooring, i don't expect silence but where i lived before was a new ish house and only the stairs made a lot of noise, not the floor itself, but then it was half the size so the span was nowhere near as wide for the joists.

 

[Leofric]

Does the stud wall run parallel to the floor joists ,when it should be built off double joists , or at right angles to the joists, when it should be built off noggins between joists
Is there herringbone strutting or noggins/timber blocks at mid span of the joists ,which there should be for spans over 2.5m

 

[Kton2002]

Yes there are noggins installed - saw them before it was all plaster boarded up