Sorry,,, another question....

I understand that the stone resin shower trays are very heavy. The position
of where I want my shower will mean that I need to drill holes through the
joists (estimated around 3 of them) to get the waste pipe through.

Will the drilled joists with what I believe to be 1.5 inch plumbing be
strong enough to support the tray?

Also, from Googling I understand that I need to mount the tray on a mortar
base. What I thought I would do is replace the current MDF floor boards with
a suitable hard wood that I can tile on top of.

I presume then I just put my mortar mix on top of my new boards and set the
resin tray into that.

My question is do I just put a flat layer of mortar on the floor or at
strategic points?

Will the mortar make the shower tray higher than the tiles?

I presume I just scrape away the excess around the outside edge of the tray
to make a neat finish?

Sorry for the beginners questions but I know nothing about this at all! I'm
determined to learn and do this myself rather than get a plumber in - famous
last words!

CM.

On Wed, 18 Aug 2004 13:29:22 +0000 (UTC), "Charles Middleton"
wrote:

Sorry,,, another question....

I understand that the stone resin shower trays are very heavy. The position
of where I want my shower will mean that I need to drill holes through the
joists (estimated around 3 of them) to get the waste pipe through.

Will the drilled joists with what I believe to be 1.5 inch plumbing be
strong enough to support the tray?


This could be a bad idea. The waste plumbing for a shower tray is
either 32 or 40mm so I would check. Also you have to have a
reasonable slope for the water to run away. Drilling holes of this
size in a floor joist can be a bad idea because of the weakening
effect - I would seek professional advice on that.


Also, from Googling I understand that I need to mount the tray on a mortar
base. What I thought I would do is replace the current MDF floor boards with
a suitable hard wood that I can tile on top of.

Generally 18mm WBP ply (commonly available) is a good choice.



I presume then I just put my mortar mix on top of my new boards and set the
resin tray into that.

My question is do I just put a flat layer of mortar on the floor or at
strategic points?

You need a mortar base for the whole thing. This is to take out
unevennesses in the finish of the underside so that the load is spread
evenly. The manufacturer's instructions will normally stipulate it
and void the warranty if you don't.

Will the mortar make the shower tray higher than the tiles?

It would do. I would suggest you put the tray in place and tile up
to it. For other bathroom fittings like toilet and pedestal basic
etc. then tile underneath - it's easier and better.


I presume I just scrape away the excess around the outside edge of the tray
to make a neat finish?

Sorry for the beginners questions but I know nothing about this at all! I'm
determined to learn and do this myself rather than get a plumber in - famous
last words!

CM.


..andy

To email, substitute .nospam with .gl

"Andy Hall" wrote in message
...
On Wed, 18 Aug 2004 13:29:22 +0000 (UTC), "Charles Middleton"
wrote:

This could be a bad idea. The waste plumbing for a shower tray is
either 32 or 40mm so I would check. Also you have to have a
reasonable slope for the water to run away. Drilling holes of this
size in a floor joist can be a bad idea because of the weakening
effect - I would seek professional advice on that.

Another badly planned project on my part then. I'm not sure what other
options I have and the shower & tray is arriving tomorrow. I thought that it
was safe to put holes in the joists providing that a) it was close to the
supporting wall and b) the hole went through the middle of the joist and c)
the diameter of the hole was no bigger than two thirds of the joist?

Also, I was planning to put a slight incline on the run through the joists
to provide this.

Generally 18mm WBP ply (commonly available) is a good choice.

So board the floor with 18mm WBP and then mount tray on motor base on top of
that.

You need a mortar base for the whole thing. This is to take out
unevennesses in the finish of the underside so that the load is spread
evenly. The manufacturer's instructions will normally stipulate it
and void the warranty if you don't.

So the mortar really provides a base between the ply and the bottom of the
tray which I presume doesn't touch the floor. Its likely in this case then
that the mortar will be contained inside and underneath the tray - no
problem.

CM.

"Charles Middleton" wrote in message
...

"Andy Hall" wrote in message
...
On Wed, 18 Aug 2004 13:29:22 +0000 (UTC), "Charles Middleton"
wrote:

This could be a bad idea. The waste plumbing for a shower tray is
either 32 or 40mm so I would check. Also you have to have a
reasonable slope for the water to run away. Drilling holes of this
size in a floor joist can be a bad idea because of the weakening
effect - I would seek professional advice on that.

Another badly planned project on my part then. I'm not sure what other
options I have and the shower & tray is arriving tomorrow. I thought that
it
was safe to put holes in the joists providing that a) it was close to the
supporting wall and b) the hole went through the middle of the joist and
c)
the diameter of the hole was no bigger than two thirds of the joist?

Also, I was planning to put a slight incline on the run through the joists
to provide this.

Generally 18mm WBP ply (commonly available) is a good choice.

So board the floor with 18mm WBP and then mount tray on motor base on top
of
that.

You need a mortar base for the whole thing. This is to take out
unevennesses in the finish of the underside so that the load is spread
evenly. The manufacturer's instructions will normally stipulate it
and void the warranty if you don't.

So the mortar really provides a base between the ply and the bottom of the
tray which I presume doesn't touch the floor. Its likely in this case then
that the mortar will be contained inside and underneath the tray - no
problem.

CM.


I had a similar problem where I needed to run a soil pipe through a joist,
and remove all but about an inch of it. So, I made up a steel plate about a
foot long, full joist height from 5mm steel, with a suitable cutout for the
pipe. I then welded a length of 6mm x 50mm x50mm angle iron along the bottom
of the plate for good measure. Added mounting holes and bolted the whole
thing to the joist with coach bolts, BEFORE cutting the joist.
Cut the joist with plate in place, and even if I jump up and down on it, it
has no movement at all!

Took about an hour with a metal jigsaw blade and the welder to make out of
scrap lying around the garage.

OK, so if you don't have a welder it may be a problem, but just a large
steel plate will help put strength back into the joist that you need to cut
out for the waste pipe....

Alan.

On Wed, 18 Aug 2004 15:13:29 +0000 (UTC), "Charles Middleton"
wrote:


"Andy Hall" wrote in message
.. .
On Wed, 18 Aug 2004 13:29:22 +0000 (UTC), "Charles Middleton"
wrote:

This could be a bad idea. The waste plumbing for a shower tray is
either 32 or 40mm so I would check. Also you have to have a
reasonable slope for the water to run away. Drilling holes of this
size in a floor joist can be a bad idea because of the weakening
effect - I would seek professional advice on that.

Another badly planned project on my part then. I'm not sure what other
options I have and the shower & tray is arriving tomorrow. I thought that it
was safe to put holes in the joists providing that a) it was close to the
supporting wall and b) the hole went through the middle of the joist and c)
the diameter of the hole was no bigger than two thirds of the joist?

I am not sure on this. You could try pinging those in the know like
Tony Bryer.



Also, I was planning to put a slight incline on the run through the joists
to provide this.

Generally 18mm WBP ply (commonly available) is a good choice.

So board the floor with 18mm WBP and then mount tray on motor base on top of
that.

Yes.



You need a mortar base for the whole thing. This is to take out
unevennesses in the finish of the underside so that the load is spread
evenly. The manufacturer's instructions will normally stipulate it
and void the warranty if you don't.

So the mortar really provides a base between the ply and the bottom of the
tray which I presume doesn't touch the floor. Its likely in this case then
that the mortar will be contained inside and underneath the tray - no
problem.

Exactly. It needs to be under the central area and around the rim.
The manufacturer's instructions should give details, but normally
about 10mm or so is used.

Also you need to do some dry runs to align the waste plumbing. There
are shower bottle traps with a mushroom lid where you can remove the
strainer from the top. These have a rubber washer.

What I did was to do the alignment using wooden spacers to get the
height right and then adjust the plumbing. When fitting, I used a
smear of silicone under and above the washer and put it on the trap,
then positioned the tray, applied more silicone to the top part of the
fitting where it screws into the base and finally tightened it all.





CM.


..andy

To email, substitute .nospam with .gl

In article , Charles Middleton wrote:
Another badly planned project on my part then. I'm not sure what other
options I have and the shower & tray is arriving tomorrow. I thought
that it was safe to put holes in the joists providing that a) it was
close to the supporting wall and b) the hole went through the middle
of the joist and c) the diameter of the hole was no bigger than two
thirds of the joist?

Generally not. You'll find a nice diagram of what is acceptable without
calculations in a guidance note on the Tameside website -
http://www.tameside.gov.uk/tmbc8/note07.pdf

i.e. holes max D/4 at between 0.25 and 0.4 of the span

Having said this, the usual practice in domestic construction is to make
all the joists the same size, said size of course being determined by the
longest span. If the bathroom is over the kitchen and you've got (say)
50x200 joists when you really only need 50x125 over this particular span
then you can obviously chop a lot more out without causing problems but
it would need to be verified by a structural engineer.

--
Tony Bryer SDA UK 'Software to build on' http://www.sda.co.uk
Free SEDBUK boiler database browser http://www.sda.co.uk/qsedbuk.htm

Another badly planned project on my part then. I'm not sure what other
options I have and the shower & tray is arriving tomorrow. I thought that
it
was safe to put holes in the joists providing that a) it was close to the
supporting wall and b) the hole went through the middle of the joist and
c)
the diameter of the hole was no bigger than two thirds of the joist?

Also, I was planning to put a slight incline on the run through the joists
to provide this.



I have just looked in a plumbing manual (from 1995) - it says holes cannot
be bigger than 1/4 of the depth of the beam and the zone in which they can
be made is between 0.25 and 0.4 of the length of the beam from wall.
Also,the holes must not be below the centre of the beam or closer than 3
times the diameter to any other holes.

Dave

"logized" wrote in message
...

I have just looked in a plumbing manual (from 1995) - it says holes cannot
be bigger than 1/4 of the depth of the beam and the zone in which they can
be made is between 0.25 and 0.4 of the length of the beam from wall.
Also,the holes must not be below the centre of the beam or closer than 3
times the diameter to any other holes.

Dave

Thanks for the info. What's the typical depth of a joist? My house was built
in 1995 if it makes any difference.

CM.

"Charles Middleton" wrote in message
...

"logized" wrote in message
...

I have just looked in a plumbing manual (from 1995) - it says holes
cannot
be bigger than 1/4 of the depth of the beam and the zone in which they
can
be made is between 0.25 and 0.4 of the length of the beam from wall.
Also,the holes must not be below the centre of the beam or closer than 3
times the diameter to any other holes.

Dave

Thanks for the info. What's the typical depth of a joist? My house was
built
in 1995 if it makes any difference.

CM.


I don't know what would be a typical depth of joist, I suppose it depends on
the span length and building regulations.
Here is a web page that agrees with the specifications for holes in joists
in my plumbing manual -
http://www.ukcopperboard.co.uk/downl...per%20tube.pdf

Dave

Charles Middleton wrote:


Thanks for the info. What's the typical depth of a joist? My house was built
in 1995 if it makes any difference.

between 175 and 220mm is common.

Have you considered building a platform to put the shower on? That would
then let you run the waste above the floor level. Once boxed in and
tiled it looks quite neat.

--
Cheers,

John.

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