Floor Joist has deep cut

[xdrive]

Hi.

I've noticed 2 joists have pretty deep cuts where they rest on wall.

Do they need changing?

Also joist in living room is attached to neighbours joist by 2 nails overlapping by 80mm only. Is that sufficient?

Also noggins are made up of thin floor boards? Is it best to change to 3x2s

1930s semi!

Cheers

Also a couple of joists have horizontal cracks. Would these need sistering or are these cracks expected in aged timber.

 

[foxhole]

Have you removed chimney breast?

 

[xdrive]

Yes. The chimney breasts have been removed including chimney stack from roof

 

[Deleted member 174758]

I've noticed 2 joists have pretty deep cuts where they rest on wall.

Do they need changing?

Well they still appear to have bearing on the top of the masonry, although not by much. TBH I'd probably fishplate them both sides with some 18mm plywood about the same width as the depth of the joists and maybe a metre in length. Stitch with #10 (5.0mm) screws. Alternatively sister and bolt together (minimum something like four M12 coach bolts)

Also joist in living room is attached to neighbours joist by 2 nails overlapping by 80mm only. Is that sufficient?

It's a lot under spec, I'd say. Can you get access to sister-up? If not would some form of support be feasible? Personally I'd want to do something with that

Also noggins are made up of thin floor boards? Is it best to change to 3x2s

Technically they are solid strutting (noggins are in walls) and they are probably more effective than 3 x 2s would be because they are a similar depth to the joists - 3 x 2s would be a lot shallower. There is a persistent and pervasive myth that "noggins" (i.e. solid strutting) in floors adds strength and carry load. Not really. What strutting does do is to stiffen the floor, i.e. remove bounciness. To do this the struts really need to transmit sideways load into adjoining joists as well as to prevent the joists from twisting under load, and to do that they must be at least 80% as deep as the original joists and ideally (although not absolutely) as thick as the originals (assuming solid strutting).

1930s semi!

All goes to show that cowboy building is nothing new

Also a couple of joists have horizontal cracks. Would these need sistering or are these cracks expected in aged timber.

They don't seem that bad, at least not from the photo - and yes timber can split with age. If you do decide to sister them you'll also need to pocket-out the wall to carry the ends, which will need to be envelope wrapped in a damp proof membrane to prevent rotting, and then the masonry made good. Quite a bit of extra work

 

[tony1851]

When installing a new floor, the traditional herringbone strutting was always more efficient than solid blocking pieces.

 

[Deleted member 174758]

When installing a new floor, the traditional herringbone strutting was always more efficient than solid blocking pieces.

Indeed, but in jobs like this where the floorboards are already in place they are rarely an option unless you want to massively increase the amount of work and expenditure involved