Notching joist to fit shower tray

[yartin]

Hi
I found a shower tray to buy, checked the waste and bathroom joist, I have this problem:
The tray has a linear waste, dimension of the assembly under tray is 120mm deep and 350mm long. This waste runs along exactly on a joist , I guess needs a slightly bigger cut probably 140mm deep and 370mm long. Joists are 200mm deep, is this safe/possible as will weaken the joist? It is the first joist running along outside wall. The notch will be 520mm away from one end of the joist, the whole length of joist is 2400mm.

Thanks

 

[blup]

140mm out of a 200mm joist will dangerously weaken it. Can you shift the shower tray to the side so it runs alongside the joist?

Blup

 

[Dereekoo]

can't you turn the tray around 90 degrees and see if the position of the outlet changes.

 

[yartin]

140mm out of a 200mm joist will dangerously weaken it. Can you shift the shower tray to the side so it runs alongside the joist?

Blup

I don't want to make a false wall and all that so no can't shift the tray.

There is no way to enforce it? How about hardwood timber like plywood screwed to joist over the span? Metal support? Being the first joist, there's not much load on that part if it matters to make life easier.

 

[yartin]

can't you turn the tray around 90 degrees and see if the position of the outlet changes.

No because of the size and shape of the bathroom.
It's rectangular tray.

 

[cdbe]

I would trim it off the next joist, with a 2.4m span you'll get away with it.

 

[Notch7]

Yeah trimmer sounds best option.

prop from below with some wedged 4 x 2.

obviously it transfers all load to next joist - which normally would be doubled up, but as it’s close to the wall maybe ok.

 

[yartin]

I would trim it off the next joist, with a 2.4m span you'll get away with it.

View attachment 298281

Thanks but sorry don't understand how does it work? In your drawing, is the the joist on the right the "next joist"? I don't get the rest

 

[blup]

Being the first joist, there's not much load on that part if it matters to make life easier.

The load is from the shower tray and the person in it, so it is significant.

Blup

 

[Dereekoo]

The load is from the shower tray and the person in it, so it is significant.

Blup

Its all relative, joists are sized to take loads either side of it and since the joist is against the wall it will only be taking half the load it was designed for. Also standard floor design loads equate to 2 adults standing on every square metre of the floor area and unless you are having a party in the bathroom are not likely to be achieved . Trimmer joist fixed to wall and 2nd joist is the way ahead.

 

[blup]

I agree, though we don’t know what the construction of the wall is like

Blup

 

[yartin]

Trimmer joist fixed to wall and 2nd joist is the way ahead.

Space between wall and the first joist being notched is less than 100mm, can't see how it's possible to fix trimmer joist to wall.

 

[yartin]

though we don’t know what the construction of the wall is like

Blup

It's outside wall, brick with cavity.

 

[Dereekoo]

Space between wall and the first joist being notched is less than 100mm, can't see how it's possible to fix trimmer joist to wall.

Fix joist hanger to wall after you have cut way the section of the 1st joist you need to move out of the way

 

[Dereekoo]

An actual sketch of your layout would possibly help