Notching Joists Will Thye Need Sistering?

[thomp1983]

Hi all,

Sometime prior to buying our house someone has butchered in some 22mm rad pipes that have always squeaked and rubbed on the floorboards.

I'll be laying new flooring next week so today I'm on sorting out the pipework. The original notches in the joists were just enough to stuff 2 22mm pipes in with no fixings or clearance, I've had to open them out so there's room for proper clips and clearance.

The joists are 8x2 inches with a span of roughly 4m. The notches are 1800mm from one end of the joist and at that end the joists are supported by a steel that's 950mm from the notches.

The notches themselves are approx 90mm wide by 50mm deep.

Do you think ill need to sister the joists and if so how long will the sistering bits need to be?

Original notches,

Now enlarged to work properly.

Thanks
Chris.

 

[Wayners]

Watch from 4.35 to 6mins in.
Shows you what you need to do.

 

[^woody^]

400 x 100 x 9mm ply glued and screwed centrally across the notch area

 

[HERTS P&D]

400 x 100 x 9mm ply glued and screwed centrally across the notch area

On both sides of the joist?

Andy

 

[Lower]

Irrelevant of whether the notches are too large, you've removed the land that the floorboard needs to sit on the left side where the floorboard should bridge the notch. That side of the floorboard will be unsupported.

 

[HERTS P&D]

Wider floor boards.

Andy

 

[thomp1983]

Whole floors being replaced, the bits that are down still are just so there's something to move around on

 

[^woody^]

On both sides of the joist?

Andy

Just the one side in this case, it's not too bad

 

[thomp1983]

Started on with the suggestions above today, decided to go both sides where possible as I've enough offcuts from cutting the sheets to land on the joists.

Think I've another half a dozen which I should get done tomorrow then I need to reclip the cables and I can think about laying the floor.

 

[mattylad]

Where that plastic to copper joint is, I'd ensure that the floorboards around it can easily be removed for when it invariably leaks in several years time

Same for the joints under the rad.

 

[cdbe]

Where that plastic to copper joint is, I'd ensure that the floorboards around it can easily be removed for when it invariably leaks in several years time

Same for the joints under the rad.

As it's a bathroom, probably easier to keep a picture for reference and access via ceiling below if necessary rather than pulling up the floor.

I use plastic myself but don't conceal joints in floors just in case!

They just live in my cupboard of plumbing shame

 

[thomp1983]

Not sure why you think it's a bathroom, it's going to be my daughters bedroom.

I'm not getting into an argument about plastic fittings, I've not personally suffered a failure in 20 years so I'm happy enough using them when concealed but it's easy enough to the lay the floor in a way that I can still access it if required.