Strengthening Floor Joists

[senjers]

Good evening.

I have a 2 story extension which has a very flexible floor on the 1st floor. I lifted up the floor boards and found that the floor is resting on 4*2 joists which are floating on top of 4*2 inch ceiling joists.

Not actually floating as they are resting on a 1 inch baton at the ends near the wall. There are a few retrofitted wooden braces nailed in which tie some of the joists together, which was a temp fix at some point.

I would like to fit a bathroom in this room, so would like to strengthen the floor to hold substantial weight (bath).

I have come up with a few options and would welcome any help in deciding. In order of expense/ effort. Ideally not dropping the ceiling in the room below.

1. Fit more braces (steel nail plates or metal struts with coach bolts).

2. Drop the top joist on to bottom and screwing through with screws along its length

3. Put new 6*2 joist alongside the existing ceiling joists. I am not sure how to tie these into the walls.

4. Remove all and start afresh.

Many thanks for your time.

 

[catlad]

Sounds like an extension to bob the builders wendy house. Start again is my advise it will be cheaper in the long run.

 

[Johnmelad]

4.

 

[b21playa]

Remove and start again, using the correctly sized timbers for the span

 

[geraldthehamster]

1. Fit more braces (steel nail plates or metal struts with coach bolts).

2. Drop the top joist on to bottom and screwing through with screws along its length

3. Put new 6*2 joist alongside the existing ceiling joists. I am not sure how to tie these into the walls.

4. Remove all and start afresh.

Many thanks for your time.

3. Size depends on span. Joist hangers.

cheers
Richard

 

[senjers]

Many thanks for your time.

I am going for 3 and leave the ceiling below. The wall hangers are going into stone.

Is it best to use a disc cutter and sink wall hangers into the slot with muck or bolt a timmer to the wall with some anchor bolts at max 600mm centres? If so as the trimmer is bolted what size does it need to be I am thinking of 6*3 as the trimmer will need to be on top of the ceiling joists and I need to match the floor height to the adjoining room.

 

[senjers]

The room the span is 2.5m between walls, and the trimmer will need to be 3.5m long

 

[geraldthehamster]

Many thanks for your time.

I am going for 3 and leave the ceiling below. The wall hangers are going into stone.

Is it best to use a disc cutter and sink wall hangers into the slot with muck or bolt a timmer to the wall with some anchor bolts at max 600mm centres? If so as the trimmer is bolted what size does it need to be I am thinking of 6*3 as the trimmer will need to be on top of the ceiling joists and I need to match the floor height to the adjoining room.

I'd have thought a trimmer would be easier. I'm not an engineer but I'd have thought 4x2 would be adequate if it's fixed to the wall. I'm prepared as always to be shot down by a proper builder, though I have helped a friend actually do this in a barn conversion.

Cheers
Richard

 

[senjers]

Many thanks for your help