Against an outside wall a new shower tray waste lines up too near to a
floor joist under it - how best to clear the way without making the
structure weaker (ideally stronger if poss as will be under a shower
tray)

ascii art - w = outside wall, I = joists (centre one is "in the way"
approx 6inch out from wall) joist spacings approx 600mm :-

current:-

wwwww
I I I
I I I
I I I

can I just:-

wwwww
I____I
I I I
I I I

or am i better doing something like

wwwww
I I I
I I I
I III I
I II I
I I I
I I I

i.e, bolting a new joist to old and locating the new into the wall,
then remove the bit in the way

Ta
Jim K

Jim K wrote:

Against an outside wall a new shower tray waste lines up too near to a
floor joist under it - how best to clear the way without making the
structure weaker (ideally stronger if poss as will be under a shower
tray)

ascii art - w = outside wall, I = joists (centre one is "in the way"
approx 6inch out from wall) joist spacings approx 600mm :-

current:-

wwwww
I I I
I I I
I I I

can I just:-

wwwww
I____I
I I I
I I I

or am i better doing something like

wwwww
I I I
I I I
I III I
I II I
I I I
I I I

i.e, bolting a new joist to old and locating the new into the wall,
then remove the bit in the way

In your middle picture, are you cutting the middle joist right through,
or just cutting a channel out of the top?

You say the waste comes down directly above the middle joist, some
6 inches from wall. By "waste" do you mean a waste unit incorporating
trap, or just a piece of pipe? If the problem is with the size of the
trap unit, it might be worth investigating whether you could just take
a bit of pipe down from the tray, and locating a separate trap partway
between the joists.

If the waste does not need room to the right of the middle joist's
existing right hand edge, and if there's enough gap between waste
and wall, one solution might be just to fit a doubler alongside,
without digging a separate hole into the wall for it. Zoomed in,
it would look something like this:

WWWWWWWWWW
IIIIJJJJ
IIIIJJJJ
IIIIJJJJ
CCCCJJJJ
CCCCJJJJ
CCCCJJJJ
IIIIJJJJ
IIIIJJJJ
IIIIJJJJ
IIII

C is the channel you've cut into joist I
J is a length of spare joist, laid adjacent to I and bolted through both.
What the diagram soesn't show is that I is sunk into the wall but J is not.

I think this would be feasible if there's enough of I bewteen C and W to
take a few bolts. It might even be feasible if the waste is so wide that
you might need to extend the channel C to the right into J, but this would
depend on how deep your channel is in relation to the depth of the joists.

If it's like this (side view):

IIICCCIII
IIICCCIII
IIIIIIIII
IIIIIIIII

and the joist I has been weakened to half its depth, then if the doubler
J is cut to a similar profile, then the combined cross sectional area of
I and J below the channel is the same as that of I where uncut, and so the
strength should be the same.

If the waste protrudes only a little bit, you may be able to fit a couple
of spacer planks S, so the waste can protrude into gap G, like this:

WWWWWWWWWW
IIIISJJJJ
IIIISJJJJ
IIIISJJJJ
CCCCGJJJJ
CCCCGJJJJ
CCCCGJJJJ
IIIISJJJJ
IIIISJJJJ
IIIISJJJJ
IIII

On 10 Oct, 10:16, Jim K wrote:
Against an outside wall a new shower tray waste lines up too near to a
floor joist under it - how best to clear the way without making the
structure weaker (ideally stronger if poss as will be under a shower
tray)

ascii art - w = outside wall, I = joists (centre one is "in the way"
approx 6inch out from wall) joist spacings approx 600mm :-

current:-

wwwww
I * I * I
I * I * I
I * I * I

can I just:-

wwwww
I____I
I * I * I
I * I * I

or am i better doing something like

wwwww
I * * I *I
I * * I *I
I * III *I
I * II * I
I * I * I
I * I * I

i.e, bolting a new joist to old and locating the new into the wall,
then remove the bit in the way

Ta
Jim K

There are special shallow traps for under shower trays, that mean the
waste can be above floor level.

On Sun, 10 Oct 2010 04:59:28 -0700 (PDT), harry wrote:

There are special shallow traps for under shower trays, that mean the
waste can be above floor level.

Yup - stick one of these in

http://www.a-s-m.com/hepvosanitarywastevalve.html

only a bend needed to connect it, no trapped water to stink and no
siphonage.
--
Peter.
The gods will stay away
whilst religions hold sway

On 10 Oct, 13:16, PeterC wrote:
On Sun, 10 Oct 2010 04:59:28 -0700 (PDT), harry wrote:
There are special shallow traps for under shower trays, that mean the
waste can be above floor level.

Yup - stick one of these in

http://www.a-s-m.com/hepvosanitarywastevalve.html

only a bend needed to connect it, no trapped water to stink and no
siphonage.
--
Peter.
The gods will stay away
whilst religions hold sway

I am a great fan of them and have used 3 already in this house ;)

thing is the joist is directly below the hole in the tray so fitting
"anything" there including a stub pipe leading to a hepvo is currently
*impossible*.

Jim K

On 10 Oct, 12:59, harry wrote:
On 10 Oct, 10:16, Jim K wrote:



Against an outside wall a new shower tray waste lines up too near to a
floor joist under it - how best to clear the way without making the
structure weaker (ideally stronger if poss as will be under a shower
tray)

ascii art - w = outside wall, I = joists (centre one is "in the way"
approx 6inch out from wall) joist spacings approx 600mm :-

current:-

wwwww
I I I
I I I
I I I

can I just:-

wwwww
I____I
I I I
I I I

or am i better doing something like

wwwww
I I I
I I I
I III I
I II I
I I I
I I I

i.e, bolting a new joist to old and locating the new into the wall,
then remove the bit in the way

Ta
Jim K

There are special shallow traps for under shower trays, that mean the
waste can be above floor level.

yes with ugly raised trays etc - but not with the low level look I'm
after... tray is only 40mm high..

Jim K

On 10 Oct, 11:26, Ronald Raygun wrote:
Jim K wrote:
Against an outside wall a new shower tray waste lines up too near to a
floor joist under it - how best to clear the way without making the
structure weaker (ideally stronger if poss as will be under a shower
tray)

ascii art - w = outside wall, I = joists (centre one is "in the way"
approx 6inch out from wall) joist spacings approx 600mm :-

current:-

wwwww
I I I
I I I
I I I

can I just:-

wwwww
I____I
I I I
I I I

or am i better doing something like

wwwww
I I I
I I I
I III I
I II I
I I I
I I I

i.e, bolting a new joist to old and locating the new into the wall,
then remove the bit in the way

In your middle picture, are you cutting the middle joist right through,
or just cutting a channel out of the top?

right through was my initial thought....

You say the waste comes down directly above the middle joist, some
6 inches from wall.

mmm the waste hole in the tray is 90mm diameter, it's *centre* will be
abt 165mm from the wall - so the edge of any notching etc would be
around 4inch from the wall...

By "waste" do you mean a waste unit incorporating
trap, or just a piece of pipe?

top access shower trap - ideally of course I don't want to have the
displeasure pf pulling up boards etc to get at any of this in the
future...

If the problem is with the size of the
trap unit, it might be worth investigating whether you could just take
a bit of pipe down from the tray, and locating a separate trap partway
between the joists.

If the waste does not need room to the right of the middle joist's
existing right hand edge, and if there's enough gap between waste
and wall, one solution might be just to fit a doubler alongside,
without digging a separate hole into the wall for it. Zoomed in,
it would look something like this:

seems I'll have 4 inch - is that enough to make a proper connection or
would I be better fitting new one into wall?

I think this would be feasible if there's enough of I bewteen C and W to
take a few bolts. It might even be feasible if the waste is so wide that
you might need to extend the channel C to the right into J, but this would
depend on how deep your channel is in relation to the depth of the joists.

If it's like this (side view):

IIICCCIII
IIICCCIII
IIIIIIIII
IIIIIIIII

and the joist I has been weakened to half its depth, then if the doubler
J is cut to a similar profile, then the combined cross sectional area of
I and J below the channel is the same as that of I where uncut, and so the
strength should be the same.

If the waste protrudes only a little bit, you may be able to fit a couple
of spacer planks S, so the waste can protrude into gap G, like this:

WWWWWWWWWW
IIIISJJJJ
IIIISJJJJ
IIIISJJJJ
CCCCGJJJJ
CCCCGJJJJ
CCCCGJJJJ
IIIISJJJJ
IIIISJJJJ
IIIISJJJJ
IIII

mmm thanks for your thoughts on this :)

Jim K

"PeterC" wrote in message
...
On Sun, 10 Oct 2010 04:59:28 -0700 (PDT), harry wrote:

There are special shallow traps for under shower trays, that mean the
waste can be above floor level.

Yup - stick one of these in

http://www.a-s-m.com/hepvosanitarywastevalve.html

only a bend needed to connect it, no trapped water to stink and no
siphonage.

What a useful thing! Thanks for posting that Peter.


--
Dave - The Medway Handyman
www.medwayhandyman.co.uk

On 10 Oct, 13:57, "The Medway Handyman" davidno-spam-
wrote:
"PeterC" wrote in message

...

On Sun, 10 Oct 2010 04:59:28 -0700 (PDT), harry wrote:

There are special shallow traps for under shower trays, that mean the
waste can be above floor level.

Yup - stick one of these in

http://www.a-s-m.com/hepvosanitarywastevalve.html

only a bend needed to connect it, no trapped water to stink and no
siphonage.

What a useful thing! Thanks for posting that Peter.

flabbergast on ya mean you've never seen them?!? /flabbergast

Fantastic things, been around for yonks - even mentioned on here at
least 7 years ago....

Jim K

On Oct 10, 10:16*pm, John Rumm wrote:
On 10/10/2010 10:16, Jim K wrote:



Against an outside wall a new shower tray waste lines up too near to a
floor joist under it - how best to clear the way without making the
structure weaker (ideally stronger if poss as will be under a shower
tray)

ascii art - w = outside wall, I = joists (centre one is "in the way"
approx 6inch out from wall) joist spacings approx 600mm :-

current:-

wwwww
I * I * I
I * I * I
I * I * I

can I just:-

Use a trimmer joist:

wwwwwwwwwwww
I * * * * I
I * * * * I
I * * * * I
A####C####B
I * *I * *I
I * *I * *I
I * *I * *I
I * *I * *I

Nail joist hangers on the sides of the existing two that don't need
cutting (at A & B). Chop the end off the one getting in the way, place a
new trimmer joist between the other joists using the hangers, and then
put a hanger in the middle of that (at C) to pick up the cut end.


Yup, thats the way... but hangers? Normally just whack a couple nails
in.


NT

On Sun, 10 Oct 2010 13:57:43 +0100, The Medway Handyman wrote:

"PeterC" wrote in message
...
On Sun, 10 Oct 2010 04:59:28 -0700 (PDT), harry wrote:

There are special shallow traps for under shower trays, that mean the
waste can be above floor level.

Yup - stick one of these in

http://www.a-s-m.com/hepvosanitarywastevalve.html

only a bend needed to connect it, no trapped water to stink and no
siphonage.

What a useful thing! Thanks for posting that Peter.

YW.
I first used one about 9 years ago. Had to fit a new 1.5 bowl sink and the
waste supplied needed almost all of the top shelf of the cupboard and a
larger hole through into the cavity.
Bringing the waste /forwards/ then through 180 deg. allowed the HepVo just
to be inside the wall and used v. little space in the cupboard. The latter
point was important as the user is disabled and prefers not to use the
bottom shelves if possible.
--
Peter.
The gods will stay away
whilst religions hold sway

On Sun, 10 Oct 2010 13:16:58 +0100, PeterC wrote:

http://www.a-s-m.com/hepvosanitarywastevalve.html

only a bend needed to connect it, no trapped water to stink and no
siphonage.

But remember anything accidentally dropped down the plug hole may
well disappear for ever rather than being caught in the traditional
trap.
Useful thing to know about though.

--
Cheers
Dave.

On Mon, 11 Oct 2010 09:16:44 +0100 (BST), Dave Liquorice wrote:

On Sun, 10 Oct 2010 13:16:58 +0100, PeterC wrote:

http://www.a-s-m.com/hepvosanitarywastevalve.html

only a bend needed to connect it, no trapped water to stink and no
siphonage.

But remember anything accidentally dropped down the plug hole may
well disappear for ever rather than being caught in the traditional
trap.
Useful thing to know about though.

Oh yes! Discovered that.
--
Peter.
The gods will stay away
whilst religions hold sway

"John Rumm" wrote in message
...
On 10/10/2010 10:16, Jim K wrote:
Against an outside wall a new shower tray waste lines up too near to a
floor joist under it - how best to clear the way without making the
structure weaker (ideally stronger if poss as will be under a shower
tray)

ascii art - w = outside wall, I = joists (centre one is "in the way"
approx 6inch out from wall) joist spacings approx 600mm :-

current:-

wwwww
I I I
I I I
I I I

can I just:-

Use a trimmer joist:


Yes that's the way joists got round the hearths of the fireplaces in our old
house (I had the opposite problem to the op in filling the gap when the
hearths were removed.).

Incidentally, if screwed on, floorboards are surprisingly good at holding up
joists, as I found when moving a rad, and discovered several joists didn't
actually reach the wall at all as the ends had rotted off: or even been
burnt off by the old fireplaces...

S