undersized joists in old house

[mordzy]

Ive just pulled down the cielining in my front room (3 layers of plaster board) as part of a room renovation. I plan to remove all the old electrical cables, secure the heating pipes etc. its an old house and the floor above has always been a bit bouncy. Looking at the 'joists' used they are laughably small. 3x3" and notched to sit on the beams. Its 200 years old is the house so perhaps thats just how they did it, used what they had.

Can anyone suggest a way to sure up the ceiling without coming too far down? the ceiling is quite low as it is.

 

[Koolpc]

If it were me, i would sister other joists onto existing

 

[mordzy]

If it were me, i would sister other joists onto existing

Could you go into a bit more detail with this? I'm not sure what you mean

 

[Mr Chibs]

What width apart are the joists?

Sistering is where you leave the current joists where they are and put another one to the side of the original, screwed/bolted together.

Are you planning on increasing the weight/load on the floor of the room above? If not perhaps just leave it alone, unless there is an issue.

My old bathroom floor had what looked like 2x3 as joists and should have been much larger... decided as it had always been like that, that I'd leave it alone.

 

[Koolpc]

Could you go into a bit more detail with this? I'm not sure what you mean

Bolt new joists directly to the existing ones, thus strengthening the structure and making it more rigid.

 

[bernardgreen]

Its 200 years old is the house so perhaps thats just how they did it, used what they had.

200 years ago the timber used in most buildings was slow grown and thus much better quality than the rapid grown poor quality timber used in so many recently built houses,

 

[^woody^]

Noggins are better for stiffening a timber floor

 

[Koolpc]

Noggins are better for stiffening a timber floor

Agree. Plus, sistering would also give more strength if there is bounce in the timbers length

 

[jacko555]

I cannot see the entire ceiling, but could you not run 2 more beams horizontally, effectively halving the 3x3 span?

That'd increase the loaf capacity and prevent bounce.

 

[Koolpc]

I cannot see the entire ceiling, but could you not run 2 more beams horizontally, effectively halving the 3x3 span?

That'd increase the loaf capacity and prevent bounce.

Another good point

 

[tony1851]

It's possible that the bounce is coming from the main beam(s) running acrossways. Consider beefing them up first before doing anything with the 3x3 joists.

 

[Koolpc]

It's possible that the bounce is coming from the main beam(s) running acrossways. Consider beefing them up first before doing anything with the 3x3 joists.

Even one extra beam inbetween existing ones would be a massive improvement.

 

[mordzy]

What width apart are the joists?

Sistering is where you leave the current joists where they are and put another one to the side of the original, screwed/bolted together.

Are you planning on increasing the weight/load on the floor of the room above? If not perhaps just leave it alone, unless there is an issue.

My old bathroom floor had what looked like 2x3 as joists and should have been much larger... decided as it had always been like that, that I'd leave it alone.

No problems, other than its a bit bouncy. no additional load either. Just while its down and didn't look right, I thought if make it right before replasterboarding. Because the joists are notched to sit on the big beams I thought theres even less holding them. If I sister them as suggested, what size would you use? a normal size joist would sit too low for the ceiling. Would you also include joist hangers?

 

[mordzy]

I cannot see the entire ceiling, but could you not run 2 more beams horizontally, effectively halving the 3x3 span?

That'd increase the loaf capacity and prevent bounce.

yes but not equally as in the centre of the room between the two existing beams is a fireplace so couldn't effectible get a beam in without fouling the chimney flue

 

[mordzy]

Here's a look to the other side. and also how the joists are notched.