I'm intending to put a shower over our bath. Question is what to do with the walls.

The existing walls were covered in painted hardboard glued to lathe & plaster by the
previous owner. I've ripped it off leaving me with a slightly springy plaster surface. I'm
going to put the shower over the end of the bath opposite the taps in the 'stud' wall
along the lines of John Stumbles' wiki entry.

I have at present an open c/h system with 1.75m head above the proposed shower head; and
in due course this may be changed to a pressurised system (possibly a combi). I think the
head may be just sufficient for the time being as the existing combination mixer-tap +
shower hose gives a usable shower though not power-shower level (obviously). Also the cold
bath tap is fed via only 15mm, teed off the cold cylinder supply just before it enters the
cylinder - not ideal! I propose to change this to a tapping on the cold tank in the attic
(a la John's wiki again) fed horizontally to above the shower, then down the stud wall to
the shower and down under the bath to the bath tap. I think it needs to be in 22mm to
match the existing 22mm hot tap feed which arrives by an under floor route to the bath
tap. The 15mm cold is noticeably underpowered when filling the bath to the extent the hot
has to be throttled back 1/2 way. To improve the shower at a later date can I put a mains
shower-pump under the bath or do electrical regs require a low voltage one? Alternatively
could I put it in the attic if I intercept the cold feed to the DHW cylinder plus the new
cold shower feed? i.e. the pump would be before the cylinder rather than after it, this
having the additional benefit (perhaps?) of pressurising the kitchen tap which suffers a
very long 15mm run.

Back to the walls, I'll follow the advise to use WBP ply for the shower end, but what
about the side of the bath? Any preferences for just tiling the existing lathe & plaster
or hacking it off and replacing with WPB, a nasty mesy job, or is that overkill? All
subsequently tiled. I imagine the tiles will (hopefully) reinforce the slightly springy
plaster.

What is the best way to seal the tiles to the bath (I know about 1/2 filling it with
water)? Simple silicone caulking or use a proprietry plastic seal?

What about 'plastic' walls, what's that called, I have no experience of it.

Phil

Phil Addison wrote:
I'm intending to put a shower over our bath. Question is what to do with the walls.

The existing walls were covered in painted hardboard glued to lathe & plaster by the
previous owner. I've ripped it off leaving me with a slightly springy plaster surface. I'm
going to put the shower over the end of the bath opposite the taps in the 'stud' wall
along the lines of John Stumbles' wiki entry.

I have at present an open c/h system with 1.75m head above the proposed shower head; and
in due course this may be changed to a pressurised system (possibly a combi). I think the
head may be just sufficient for the time being as the existing combination mixer-tap +
shower hose gives a usable shower though not power-shower level (obviously). Also the cold
bath tap is fed via only 15mm, teed off the cold cylinder supply just before it enters the
cylinder - not ideal! I propose to change this to a tapping on the cold tank in the attic
(a la John's wiki again) fed horizontally to above the shower, then down the stud wall to
the shower and down under the bath to the bath tap. I think it needs to be in 22mm to
match the existing 22mm hot tap feed which arrives by an under floor route to the bath
tap. The 15mm cold is noticeably underpowered when filling the bath to the extent the hot
has to be throttled back 1/2 way. To improve the shower at a later date can I put a mains
shower-pump under the bath or do electrical regs require a low voltage one? Alternatively
could I put it in the attic if I intercept the cold feed to the DHW cylinder plus the new
cold shower feed? i.e. the pump would be before the cylinder rather than after it, this
having the additional benefit (perhaps?) of pressurising the kitchen tap which suffers a
very long 15mm run.

Back to the walls, I'll follow the advise to use WBP ply for the shower end, but what
about the side of the bath?

same prolly

Any preferences for just tiling the existing lathe & plaster
or hacking it off and replacing with WPB, a nasty mesy job, or is that overkill? All
subsequently tiled. I imagine the tiles will (hopefully) reinforce the slightly springy
plaster.

if its not flexible use it.

IOtherwise beef it up

What is the best way to seal the tiles to the bath (I know about 1/2 filling it with
water)? Simple silicone caulking or use a proprietry plastic seal?


My system, is to seal with silicone and tile OVER then then fill the gap
with grout. Sure you get hairline cracks but no leaks

What about 'plastic' walls, what's that called, I have no experience of it.

Pass.


Phil


--
Ineptocracy

(in-ep-toc-ra-cy) €“ a system of government where the least capable to
lead are elected by the least capable of producing, and where the
members of society least likely to sustain themselves or succeed, are
rewarded with goods and services paid for by the confiscated wealth of a
diminishing number of producers.

On Sat, 29 Sep 2012 01:08:56 +0100, The Natural Philosopher
wrote:


Any preferences for just tiling the existing lathe & plaster

Lathe? Lath, shirley.

--
Frank Erskine

On 29/09/2012 01:02, Phil Addison wrote:

I'm intending to put a shower over our bath. Question is what to do with the walls.

Leave them there ;-)

The existing walls were covered in painted hardboard glued to lathe & plaster by the
previous owner. I've ripped it off leaving me with a slightly springy plaster surface. I'm
going to put the shower over the end of the bath opposite the taps in the 'stud' wall
along the lines of John Stumbles' wiki entry.

I have at present an open c/h system with 1.75m head above the proposed shower head; and
in due course this may be changed to a pressurised system (possibly a combi). I think the
head may be just sufficient for the time being as the existing combination mixer-tap +
shower hose gives a usable shower though not power-shower level (obviously). Also the cold

I built a gravity fed shower for someone once with that amount of head.
He bought a Trevi shower unit designed for low pressure operation. The
results were adequate, in that lots of hot water fell out of it - just
not with much enthusiasm. Better than an electric shower though.

bath tap is fed via only 15mm, teed off the cold cylinder supply just before it enters the
cylinder - not ideal! I propose to change this to a tapping on the cold tank in the attic
(a la John's wiki again) fed horizontally to above the shower, then down the stud wall to
the shower and down under the bath to the bath tap. I think it needs to be in 22mm to
match the existing 22mm hot tap feed which arrives by an under floor route to the bath

There are a couple of ways of looking at this. The normal reason for the
dedicated cold feed tapped off a little lower in the cold cistern than
the feed to the hot water cylinder is to ensure if you drain the tank,
its not the cold that runs out first. The reality is that with so little
head you are unlikely to achieve the flow rates that would make this
possible. Couple this with the fact that most modern thermostatic
showers also have automatic shutoff if the cold fails.

tap. The 15mm cold is noticeably underpowered when filling the bath to the extent the hot
has to be throttled back 1/2 way. To improve the shower at a later date can I put a mains
shower-pump under the bath or do electrical regs require a low voltage one? Alternatively

As long as "under the bath" needs a tool to access, then its outside the
zones and a mains pressure one is ok.

Pumps typically work best when close to the cylinder, however this is
more important with more powerful pumps.

could I put it in the attic if I intercept the cold feed to the DHW cylinder plus the new
cold shower feed? i.e. the pump would be before the cylinder rather than after it, this
having the additional benefit (perhaps?) of pressurising the kitchen tap which suffers a
very long 15mm run.

You can't really pump cold water into a vented cylinder. It will just
pour out of the vent pipe back into the cistern.

Back to the walls, I'll follow the advise to use WBP ply for the shower end, but what
about the side of the bath? Any preferences for just tiling the existing lathe & plaster
or hacking it off and replacing with WPB, a nasty mesy job, or is that overkill? All
subsequently tiled. I imagine the tiles will (hopefully) reinforce the slightly springy
plaster.

Most preferable would probably be one of the cementious boards designed
for the purpose like aqua panel. However WPB would be the next best option.

You could alternatively render the existing wall with a SBR sand and
cement mortar - that will also give a reasonable waterproof backing.

(the least desirable would be plasterboard)

What is the best way to seal the tiles to the bath (I know about 1/2 filling it with
water)? Simple silicone caulking or use a proprietry plastic seal?

The trick to successfully sealing is to make sure there is enough space
for the sealant. i.e. don't tile down to the bath and then hope to add a
small fillet of silicone in the corner of the join. Its better to seal
the wall to the bath, then tile down to a tiles thickness above the
bath. Fill the bath and then fill the full depth of the gap and profile
the protruding bit of silicone bead. Once dry, let the water out. That
keeps the seal under compression in the gap, and far less likely to lose
adhesion and pull away from either side of the joint.

What about 'plastic' walls, what's that called, I have no experience of it.

There are various panels made for construction of showers. Corian is one
such material, but there are others. They often have the advantage of
coming with a decorative finish, so they need no further tiling etc.


--
Cheers,

John.

/================================================== ===============\
| Internode Ltd - http://www.internode.co.uk |
|-----------------------------------------------------------------|
| John Rumm - john(at)internode(dot)co(dot)uk |
\================================================= ================/

On 29/09/2012 02:10, Frank Erskine wrote:
On Sat, 29 Sep 2012 01:08:56 +0100, The Natural Philosopher
wrote:


Any preferences for just tiling the existing lathe & plaster

Lathe? Lath, shirley.

Don't want a lathe in the shower - it will rust!

--
Cheers,

John.

/================================================== ===============\
| Internode Ltd - http://www.internode.co.uk |
|-----------------------------------------------------------------|
| John Rumm - john(at)internode(dot)co(dot)uk |
\================================================= ================/

On 29/09/2012 01:02, Phil Addison wrote:
I'm intending to put a shower over our bath. Question is what to do with the walls.

What about 'plastic' walls, what's that called, I have no experience of it.

I've installed http://www.multipanel.co.uk/ in our shower cubicle at
home - it's basically vinyl-faced plywood which comes in sheets of
(IIRC) 8'x4'. You can apply it direct to the studs, and it makes a very
nice finish; looks good and much easier to keep clean than grouted tiles.

Not particularly cheap though (though there are cheaper suppliers; and I
suppose you need to compare the cost with reasonably high-end tiles) and
I found it very scary cutting the panels to size - one wrong cut is an
expensive mistake! Took me a long time to do, as well; I found the
instructions and method quite fiddly and awkward to understand - I feel
it's aimed at pros rather than a one-off DIY installation (for sure it
would take about a third of the time if I had to do it again now).

David

Frank Erskine wrote:
On Sat, 29 Sep 2012 01:08:56 +0100, The Natural Philosopher
wrote:


Any preferences for just tiling the existing lathe & plaster

Lathe? Lath, shirley.

I assumed there was an old Myford entombed there


--
Ineptocracy

(in-ep-toc-ra-cy) €“ a system of government where the least capable to
lead are elected by the least capable of producing, and where the
members of society least likely to sustain themselves or succeed, are
rewarded with goods and services paid for by the confiscated wealth of a
diminishing number of producers.

On Sat, 29 Sep 2012 03:57:26 +0100, John Rumm wrote:

On 29/09/2012 02:10, Frank Erskine wrote:
On Sat, 29 Sep 2012 01:08:56 +0100, The Natural Philosopher
wrote:


Any preferences for just tiling the existing lathe & plaster

Lathe? Lath, shirley.

Don't want a lathe in the shower - it will rust!

Well said, my son!
--
Peter.
The gods will stay away
whilst religions hold sway

On Sat, 29 Sep 2012 02:10:45 +0100, Frank Erskine wrote:

On Sat, 29 Sep 2012 01:08:56 +0100, The Natural Philosopher
wrote:


Any preferences for just tiling the existing lathe & plaster

Lathe? Lath, shirley.

Ooopsh sho it ish

--
Phil Addison

On Sat, 29 Sep 2012 03:56:13 +0100, John Rumm wrote:

On 29/09/2012 01:02, Phil Addison wrote:

I'm intending to put a shower over our bath. Question is what to do with the walls.

I built a gravity fed shower for someone once with that amount of head.
He bought a Trevi shower unit designed for low pressure operation. The
results were adequate, in that lots of hot water fell out of it - just
not with much enthusiasm. Better than an electric shower though.

Nice description, it'll be a pump then!

bath tap is fed via only 15mm, teed off the cold cylinder supply just before it enters the
cylinder - not ideal! I propose to change this to a tapping on the cold tank in the attic
(a la John's wiki again) fed horizontally to above the shower, then down the stud wall to
the shower and down under the bath to the bath tap. I think it needs to be in 22mm to
match the existing 22mm hot tap feed which arrives by an under floor route to the bath

There are a couple of ways of looking at this. The normal reason for the
dedicated cold feed tapped off a little lower in the cold cistern than
the feed to the hot water cylinder is to ensure if you drain the tank,
its not the cold that runs out first. The reality is that with so little
head you are unlikely to achieve the flow rates that would make this
possible. Couple this with the fact that most modern thermostatic
showers also have automatic shutoff if the cold fails.

That's good news. So perhaps I could put the pump in the linen cupboard after all, and the
existing 15mm feed would cope if its pumped? Access under the floorboards to change it to
22mm is near impossible at the mo. Its easy enough to bring a connection down from the
cold storage to avoid the existing sharing of the cylinder inlet.

has to be throttled back 1/2 way. To improve the shower at a later date can I put a mains
shower-pump under the bath or do electrical regs require a low voltage one? Alternatively

As long as "under the bath" needs a tool to access, then its outside the
zones and a mains pressure one is ok.

Good.

Pumps typically work best when close to the cylinder, however this is
more important with more powerful pumps.

Due to the damping effect of the weight of water they are pumping into? Oscillatory
damping, that is

could I put it in the attic if I intercept the cold feed to the DHW cylinder plus the new
cold shower feed? i.e. the pump would be before the cylinder rather than after it, this
having the additional benefit (perhaps?) of pressurising the kitchen tap which suffers a
very long 15mm run.

You can't really pump cold water into a vented cylinder. It will just
pour out of the vent pipe back into the cistern.

Duh, I should have known that!!

Back to the walls, I'll follow the advise to use WBP ply for the shower end, but what
about the side of the bath? Any preferences for just tiling the existing lathe & plaster
or hacking it off and replacing with WPB, a nasty mesy job, or is that overkill? All
subsequently tiled. I imagine the tiles will (hopefully) reinforce the slightly springy
plaster.

Most preferable would probably be one of the cementious boards designed
for the purpose like aqua panel. However WPB would be the next best option.

Is aqua panel any easier to handle and cut than wpb? Cost?

You could alternatively render the existing wall with a SBR sand and
cement mortar - that will also give a reasonable waterproof backing.

It's marginally stable lath & plaster now. I'm assuming the best but messy way is to strip
it off and fix a new backing board to the studs. I suppose I could fix the backing board
over the existing plaster but that feels like a bodge.

(the least desirable would be plasterboard)

Point taken.

What is the best way to seal the tiles to the bath (I know about 1/2 filling it with
water)? Simple silicone caulking or use a proprietry plastic seal?

The trick to successfully sealing is to make sure there is enough space
for the sealant. i.e. don't tile down to the bath and then hope to add a
small fillet of silicone in the corner of the join. Its better to seal
the wall to the bath, then tile down to a tiles thickness above the
bath. Fill the bath and then fill the full depth of the gap and profile
the protruding bit of silicone bead. Once dry, let the water out. That
keeps the seal under compression in the gap, and far less likely to lose
adhesion and pull away from either side of the joint.

Sounds good.

What about 'plastic' walls, what's that called, I have no experience of it.

There are various panels made for construction of showers. Corian is one
such material, but there are others. They often have the advantage of
coming with a decorative finish, so they need no further tiling etc.

Probably best if I stick with tried and tested diy tiling.

Thanks for the input.

On 29/09/2012 11:17, Phil Addison wrote:
On Sat, 29 Sep 2012 03:56:13 +0100, John Rumm wrote:

On 29/09/2012 01:02, Phil Addison wrote:

I'm intending to put a shower over our bath. Question is what to do with the walls.

I built a gravity fed shower for someone once with that amount of head.
He bought a Trevi shower unit designed for low pressure operation. The
results were adequate, in that lots of hot water fell out of it - just
not with much enthusiasm. Better than an electric shower though.

Nice description, it'll be a pump then!

Much depends on the sort of shower you like... if you gravitate toward
the big soaker head, being in a all enveloping hot rain storm kind of
sensation, then you won't need a pump. If you want something to massage
and exfoliate with a pressure washer like sensation, then you need a
*big* pump!

bath tap is fed via only 15mm, teed off the cold cylinder supply just before it enters the
cylinder - not ideal! I propose to change this to a tapping on the cold tank in the attic
(a la John's wiki again) fed horizontally to above the shower, then down the stud wall to
the shower and down under the bath to the bath tap. I think it needs to be in 22mm to
match the existing 22mm hot tap feed which arrives by an under floor route to the bath

There are a couple of ways of looking at this. The normal reason for the
dedicated cold feed tapped off a little lower in the cold cistern than
the feed to the hot water cylinder is to ensure if you drain the tank,
its not the cold that runs out first. The reality is that with so little
head you are unlikely to achieve the flow rates that would make this
possible. Couple this with the fact that most modern thermostatic
showers also have automatic shutoff if the cold fails.

That's good news. So perhaps I could put the pump in the linen cupboard after all, and the
existing 15mm feed would cope if its pumped? Access under the floorboards to change it to
22mm is near impossible at the mo. Its easy enough to bring a connection down from the
cold storage to avoid the existing sharing of the cylinder inlet.

Yup that will work fine - 15mm has adequate capacity for most showers.
Using bigger pipe just means longer to wait for hot water.

If you must get new pipes in, then its surprising what can be done with
a set of cable rods followed by a coil of speedfit ;-)

has to be throttled back 1/2 way. To improve the shower at a later date can I put a mains
shower-pump under the bath or do electrical regs require a low voltage one? Alternatively

As long as "under the bath" needs a tool to access, then its outside the
zones and a mains pressure one is ok.

Good.

Pumps typically work best when close to the cylinder, however this is
more important with more powerful pumps.

Due to the damping effect of the weight of water they are pumping into? Oscillatory
damping, that is

They blow better than they suck. If you stick a 3 bar pump on the end of
a long pipe run it will probably cavitate and not work well. It needs a
nice ready flow of water from the cylinder. With the more powerful ones
you may need a Warix or Surrey flange on the cylinder (or an Essex one
near to top on the side) to stop sucking air into the pump from the vent
pipe.

Having said that, I did a stuart turner 1.8 bar pump for SWMBO's aunt
once, and that worked fine without any changes to the cylinder. The cold
cistern was in the loft about only about 6' higher than the cylinder.

could I put it in the attic if I intercept the cold feed to the DHW cylinder plus the new
cold shower feed? i.e. the pump would be before the cylinder rather than after it, this
having the additional benefit (perhaps?) of pressurising the kitchen tap which suffers a
very long 15mm run.

You can't really pump cold water into a vented cylinder. It will just
pour out of the vent pipe back into the cistern.

Duh, I should have known that!!

Not only that, it will cause hot flushes ;-))

Back to the walls, I'll follow the advise to use WBP ply for the shower end, but what
about the side of the bath? Any preferences for just tiling the existing lathe & plaster
or hacking it off and replacing with WPB, a nasty mesy job, or is that overkill? All
subsequently tiled. I imagine the tiles will (hopefully) reinforce the slightly springy
plaster.

Most preferable would probably be one of the cementious boards designed
for the purpose like aqua panel. However WPB would be the next best option.

Is aqua panel any easier to handle and cut than wpb? Cost?

Not tried it personally... IIUC its heavy, but can be cut with an (old)
saw.

Last one I did with a backing like you describe was with WBP ply which I
then rendered prior to tiling:

http://www.internode.co.uk/loft/shower.htm

I think I would probably just go for the right board in the first place
now though ;-)

You could alternatively render the existing wall with a SBR sand and
cement mortar - that will also give a reasonable waterproof backing.

It's marginally stable lath & plaster now. I'm assuming the best but messy way is to strip
it off and fix a new backing board to the studs. I suppose I could fix the backing board
over the existing plaster but that feels like a bodge.

As long as the studs are sound and you can afford to lose 1/2" and inch
of space, its a whole lot less mess!

(the least desirable would be plasterboard)

Point taken.

What is the best way to seal the tiles to the bath (I know about 1/2 filling it with
water)? Simple silicone caulking or use a proprietry plastic seal?

The trick to successfully sealing is to make sure there is enough space
for the sealant. i.e. don't tile down to the bath and then hope to add a
small fillet of silicone in the corner of the join. Its better to seal
the wall to the bath, then tile down to a tiles thickness above the
bath. Fill the bath and then fill the full depth of the gap and profile
the protruding bit of silicone bead. Once dry, let the water out. That
keeps the seal under compression in the gap, and far less likely to lose
adhesion and pull away from either side of the joint.

Sounds good.

What about 'plastic' walls, what's that called, I have no experience of it.

There are various panels made for construction of showers. Corian is one
such material, but there are others. They often have the advantage of
coming with a decorative finish, so they need no further tiling etc.

Probably best if I stick with tried and tested diy tiling.

It works if done right...

Might be worth costing against prefab panels though. (let me know the
result - I need to do another shower shortly ;-)

--
Cheers,

John.

/================================================== ===============\
| Internode Ltd - http://www.internode.co.uk |
|-----------------------------------------------------------------|
| John Rumm - john(at)internode(dot)co(dot)uk |
\================================================= ================/

On 29/09/2012 09:01, Lobster wrote:
On 29/09/2012 01:02, Phil Addison wrote:
I'm intending to put a shower over our bath. Question is what to do
with the walls.

What about 'plastic' walls, what's that called, I have no experience
of it.

I've installed http://www.multipanel.co.uk/ in our shower cubicle at

Don't you love the way those photos always have an attractive and
slightly damp female emerging from the shower or sitting on the bath.
Never a hairy arsed bloke with a bear gut scratching his balls. Selling
the dream and not the reality!

home - it's basically vinyl-faced plywood which comes in sheets of
(IIRC) 8'x4'. You can apply it direct to the studs, and it makes a very
nice finish; looks good and much easier to keep clean than grouted tiles.

Not particularly cheap though (though there are cheaper suppliers; and I

Can you recall how much a sheet?

suppose you need to compare the cost with reasonably high-end tiles) and
I found it very scary cutting the panels to size - one wrong cut is an
expensive mistake! Took me a long time to do, as well; I found the
instructions and method quite fiddly and awkward to understand - I feel
it's aimed at pros rather than a one-off DIY installation (for sure it
would take about a third of the time if I had to do it again now).

What made it difficult?


--
Cheers,

John.

/================================================== ===============\
| Internode Ltd - http://www.internode.co.uk |
|-----------------------------------------------------------------|
| John Rumm - john(at)internode(dot)co(dot)uk |
\================================================= ================/

Phil Addison wrote:
I'm intending to put a shower over our bath. Question is what to do
with the walls.

The existing walls were covered in painted hardboard glued to lathe &
plaster by the previous owner. I've ripped it off leaving me with a
slightly springy plaster surface. I'm going to put the shower over
the end of the bath opposite the taps in the 'stud' wall along the
lines of John Stumbles' wiki entry.

I have at present an open c/h system with 1.75m head above the
proposed shower head; and in due course this may be changed to a
pressurised system (possibly a combi). I think the head may be just
sufficient for the time being as the existing combination mixer-tap +
shower hose gives a usable shower though not power-shower level
(obviously). Also the cold bath tap is fed via only 15mm, teed off
the cold cylinder supply just before it enters the cylinder - not
ideal! I propose to change this to a tapping on the cold tank in the
attic (a la John's wiki again) fed horizontally to above the shower,
then down the stud wall to the shower and down under the bath to the
bath tap. I think it needs to be in 22mm to match the existing 22mm
hot tap feed which arrives by an under floor route to the bath tap.
The 15mm cold is noticeably underpowered when filling the bath to the
extent the hot has to be throttled back 1/2 way. To improve the
shower at a later date can I put a mains shower-pump under the bath
or do electrical regs require a low voltage one? Alternatively could
I put it in the attic if I intercept the cold feed to the DHW
cylinder plus the new cold shower feed? i.e. the pump would be before
the cylinder rather than after it, this having the additional benefit
(perhaps?) of pressurising the kitchen tap which suffers a very long
15mm run.

Back to the walls, I'll follow the advise to use WBP ply for the
shower end, but what about the side of the bath? Any preferences for
just tiling the existing lathe & plaster or hacking it off and
replacing with WPB, a nasty mesy job, or is that overkill? All
subsequently tiled. I imagine the tiles will (hopefully) reinforce
the slightly springy plaster.

What is the best way to seal the tiles to the bath (I know about 1/2
filling it with water)? Simple silicone caulking or use a proprietry
plastic seal?

What about 'plastic' walls, what's that called, I have no experience
of it.

Can't comment on the plumbing side of things as I'm not well up on pumps
etc, but it's your walls I'm concerned about.

Firstly, you'll only get one chance to make it good - you can't start
ripping off tiles and re-doing stuff once the bathroom's finished...well you
could but this is not what anyone wants.

Don't shy away from removing the lath and plaster - it's not a big job and
if you line the bath with dustsheets, you can wrap them up and dump them
outside with virtually no mess.
Forget about the tiles re-inforcing the plaster - they won't, the plaster
will still be springy and flexible but the tile grout won't be - resulting
in cracked grout and water penetration in short time.
Back to the L&P.
You don't need to get all the laths off - you can board over these once the
plaster's removed, which will save on some mess - the WPB can be screwed to
the (now visible) studs, sandwiching the laths underneath.
Then you can tile as normal, or if you are on a budget, you can use pvc
cladding which I used in my bathroom 3 years ago and it still looks like
new, and at £12 for 5m by 300mm T&G white, I think it only cost me £60 for
the placcy and a fiver for adhesive.
Like this but half the price from a local supplier:
http://www.wickes.co.uk/pvcu-soffit-...m/invt/162643/

The advantages a
No grout lines to discolour.
Wipes clean just like tiles
Hardwearing and waterproof
Locks together
Installed in a tenth of the time as tiles
Cheap as chips, so eventual replacement isn't as daunting
Plain white so won't look 'out of fashion' in a few years time

On 29/09/2012 15:07, John Rumm wrote:
On 29/09/2012 09:01, Lobster wrote:
On 29/09/2012 01:02, Phil Addison wrote:
I'm intending to put a shower over our bath. Question is what to do
with the walls.

What about 'plastic' walls, what's that called, I have no experience
of it.

I've installed http://www.multipanel.co.uk/ in our shower cubicle at

Not particularly cheap though (though there are cheaper suppliers; and I

Can you recall how much a sheet?

Just checked my records, and I used this retailer:
http://tinyurl.com/ctd695r (or
http://www.rubberduckbathrooms.co.uk...oard-panel-kit)
- most economical (and I use the term loosely) method was to buy a kit
for £400 or so which was all materials, joints, sealant, adhesive etc
needed for my 1200x900mm shower. A 8'x4' sheet on its own is about £100.

suppose you need to compare the cost with reasonably high-end tiles) and
I found it very scary cutting the panels to size - one wrong cut is an
expensive mistake! Took me a long time to do, as well; I found the
instructions and method quite fiddly and awkward to understand - I feel
it's aimed at pros rather than a one-off DIY installation (for sure it
would take about a third of the time if I had to do it again now).

What made it difficult?

Terror was probably the biggest single factor - doing something wrong
and writing off a £100 panel so much head-scratching, checking,
double-checking before making any cuts or trims, drilling holes etc!

But for example, my shower is in an alcove approx 1.2x2.2m high, and of
course none of the corners are perfectly true, so you have to trim the
back panel to slot into that rectangular hole pretty well perfectly;
very little margin for error. I'm sure a more competent and confident
joiner than me would have had it done much quicker!

I didn't find the instructions particularly clear, either TBH (you use
bespoke extruded alumiumium joints in the corners, and more bespoke
trims/seals at the front edge, shower tray and ceiling)

David

On Sat, 29 Sep 2012 15:04:19 +0100, John Rumm wrote:

On 29/09/2012 11:17, Phil Addison wrote:
On Sat, 29 Sep 2012 03:56:13 +0100, John Rumm wrote:

On 29/09/2012 01:02, Phil Addison wrote:

I'm intending to put a shower over our bath. Question is what to do with the walls.

I built a gravity fed shower for someone once with that amount of head.
He bought a Trevi shower unit designed for low pressure operation. The
results were adequate, in that lots of hot water fell out of it - just
not with much enthusiasm. Better than an electric shower though.

Nice description, it'll be a pump then!

Much depends on the sort of shower you like... if you gravitate toward
the big soaker head, being in a all enveloping hot rain storm kind of
sensation, then you won't need a pump. If you want something to massage
and exfoliate with a pressure washer like sensation, then you need a
*big* pump!

LOL!

bath tap is fed via only 15mm, teed off the cold cylinder supply just before it enters the
cylinder - not ideal! I propose to change this to a tapping on the cold tank in the attic
(a la John's wiki again) fed horizontally to above the shower, then down the stud wall to
the shower and down under the bath to the bath tap. I think it needs to be in 22mm to
match the existing 22mm hot tap feed which arrives by an under floor route to the bath

There are a couple of ways of looking at this. The normal reason for the
dedicated cold feed tapped off a little lower in the cold cistern than
the feed to the hot water cylinder is to ensure if you drain the tank,
its not the cold that runs out first. The reality is that with so little
head you are unlikely to achieve the flow rates that would make this
possible. Couple this with the fact that most modern thermostatic
showers also have automatic shutoff if the cold fails.

That's good news. So perhaps I could put the pump in the linen cupboard after all, and the
existing 15mm feed would cope if its pumped? Access under the floorboards to change it to
22mm is near impossible at the mo. Its easy enough to bring a connection down from the
cold storage to avoid the existing sharing of the cylinder inlet.

Yup that will work fine - 15mm has adequate capacity for most showers.
Using bigger pipe just means longer to wait for hot water.

If you must get new pipes in, then its surprising what can be done with
a set of cable rods followed by a coil of speedfit ;-)

What happened to Hep2O, last time I was doing diy that was all the rage!

has to be throttled back 1/2 way. To improve the shower at a later date can I put a mains
shower-pump under the bath or do electrical regs require a low voltage one? Alternatively

As long as "under the bath" needs a tool to access, then its outside the
zones and a mains pressure one is ok.

Good.

Pumps typically work best when close to the cylinder, however this is
more important with more powerful pumps.

Due to the damping effect of the weight of water they are pumping into? Oscillatory
damping, that is

They blow better than they suck. If you stick a 3 bar pump on the end of
a long pipe run it will probably cavitate and not work well. It needs a
nice ready flow of water from the cylinder. With the more powerful ones
you may need a Warix or Surrey flange on the cylinder (or an Essex one
near to top on the side) to stop sucking air into the pump from the vent
pipe.

Sucking in air will be a function of the actual flow rate achieved surely? I can
appreciate problems with a big pump trying to work into a high resistance tho; but don't
the manufacturers give a flow vs head characteristic so one can predict the performance,
like the c/h circulators offer?

Having said that, I did a stuart turner 1.8 bar pump for SWMBO's aunt
once, and that worked fine without any changes to the cylinder. The cold
cistern was in the loft about only about 6' higher than the cylinder.

I'll have to start collecting pump info. Any favourite ones, or ones to avoid?

could I put it in the attic if I intercept the cold feed to the DHW cylinder plus the new
cold shower feed? i.e. the pump would be before the cylinder rather than after it, this
having the additional benefit (perhaps?) of pressurising the kitchen tap which suffers a
very long 15mm run.

You can't really pump cold water into a vented cylinder. It will just
pour out of the vent pipe back into the cistern.

Duh, I should have known that!!

Not only that, it will cause hot flushes ;-))

I wasn't going to connect it to the bog!

Back to the walls, I'll follow the advise to use WBP ply for the shower end, but what
about the side of the bath? Any preferences for just tiling the existing lathe & plaster
or hacking it off and replacing with WPB, a nasty mesy job, or is that overkill? All
subsequently tiled. I imagine the tiles will (hopefully) reinforce the slightly springy
plaster.

Most preferable would probably be one of the cementious boards designed
for the purpose like aqua panel. However WPB would be the next best option.

Is aqua panel any easier to handle and cut than wpb? Cost?

Not tried it personally... IIUC its heavy, but can be cut with an (old)
saw.

Last one I did with a backing like you describe was with WBP ply which I
then rendered prior to tiling:

http://www.internode.co.uk/loft/shower.htm

I think I would probably just go for the right board in the first place
now though ;-)

You could alternatively render the existing wall with a SBR sand and
cement mortar - that will also give a reasonable waterproof backing.

It's marginally stable lath & plaster now. I'm assuming the best but messy way is to strip
it off and fix a new backing board to the studs. I suppose I could fix the backing board
over the existing plaster but that feels like a bodge.

As long as the studs are sound and you can afford to lose 1/2" and inch
of space, its a whole lot less mess!

(the least desirable would be plasterboard)

Point taken.

What is the best way to seal the tiles to the bath (I know about 1/2 filling it with
water)? Simple silicone caulking or use a proprietry plastic seal?

The trick to successfully sealing is to make sure there is enough space
for the sealant. i.e. don't tile down to the bath and then hope to add a
small fillet of silicone in the corner of the join. Its better to seal
the wall to the bath, then tile down to a tiles thickness above the
bath. Fill the bath and then fill the full depth of the gap and profile
the protruding bit of silicone bead. Once dry, let the water out. That
keeps the seal under compression in the gap, and far less likely to lose
adhesion and pull away from either side of the joint.

Sounds good.

What about 'plastic' walls, what's that called, I have no experience of it.

There are various panels made for construction of showers. Corian is one
such material, but there are others. They often have the advantage of
coming with a decorative finish, so they need no further tiling etc.

Probably best if I stick with tried and tested diy tiling.

It works if done right...

Might be worth costing against prefab panels though. (let me know the
result - I need to do another shower shortly ;-)

--
Cheers,

John.

/================================================== ===============\
| Internode Ltd - http://www.internode.co.uk |
|-----------------------------------------------------------------|
| John Rumm - john(at)internode(dot)co(dot)uk |

--
Phil Addison

On Sat, 29 Sep 2012 17:37:34 +0100, "Phil L" wrote:

Phil Addison wrote:
I'm intending to put a shower over our bath. Question is what to do
with the walls.

Can't comment on the plumbing side of things as I'm not well up on pumps
etc, but it's your walls I'm concerned about.

Firstly, you'll only get one chance to make it good - you can't start
ripping off tiles and re-doing stuff once the bathroom's finished...well you
could but this is not what anyone wants.

Actually there is a complication, and I might just do that. We are having guests staying
in 3 weeks and I have to get it servicabel by then, but ultimately I want to pust the long
bath wall 18" into the next to room to make the bathroom a bit bigger at the expense of
the adjacent room, so I'm warming to your ideas below.

Don't shy away from removing the lath and plaster - it's not a big job and
if you line the bath with dustsheets, you can wrap them up and dump them
outside with virtually no mess.

This is true, I must admit the dust will be confined to the bathroom so not at all
insurmountable.

Forget about the tiles re-inforcing the plaster - they won't, the plaster
will still be springy and flexible but the tile grout won't be - resulting
in cracked grout and water penetration in short time.

There isn't much springiness but I do tend to agree tiling on it isn't a good idea.

Back to the L&P.
You don't need to get all the laths off - you can board over these once the
plaster's removed, which will save on some mess - the WPB can be screwed to
the (now visible) studs, sandwiching the laths underneath.

I'm warming more and more to this.

Then you can tile as normal, or if you are on a budget, you can use pvc
cladding which I used in my bathroom 3 years ago and it still looks like
new, and at £12 for 5m by 300mm T&G white, I think it only cost me £60 for
the placcy and a fiver for adhesive.
Like this but half the price from a local supplier:
http://www.wickes.co.uk/pvcu-soffit-...m/invt/162643/

Its an attractive idea, quick to do and not much wasted cash if I rip it all out. But is
it really the PVCu Soffit Board that you used? And did you run it horizontally or
vertically. I'll pop along to Wickes and have a look at it.

The advantages a
No grout lines to discolour.
Wipes clean just like tiles
Hardwearing and waterproof
Locks together
Installed in a tenth of the time as tiles
Cheap as chips, so eventual replacement isn't as daunting

Hmmm... back to the drawing board.

--
Phil Addison

On 30/09/2012 22:38, Phil Addison wrote:

If you must get new pipes in, then its surprising what can be done with
a set of cable rods followed by a coil of speedfit ;-)

What happened to Hep2O, last time I was doing diy that was all the rage!

Still available, just for some reason I have always preferred speedfit.

They blow better than they suck. If you stick a 3 bar pump on the end of
a long pipe run it will probably cavitate and not work well. It needs a
nice ready flow of water from the cylinder. With the more powerful ones
you may need a Warix or Surrey flange on the cylinder (or an Essex one
near to top on the side) to stop sucking air into the pump from the vent
pipe.

Sucking in air will be a function of the actual flow rate achieved surely? I can

Yes in the sense that if you are pumping into more flow resistance, the
required delivery rate to the pump will be less. The main issue is that
you are depending on gravity to feed the pump and so need as little flow
resistance there as possible.

appreciate problems with a big pump trying to work into a high resistance tho; but don't
the manufacturers give a flow vs head characteristic so one can predict the performance,
like the c/h circulators offer?

They do normally - e.g.:

http://www.stuart-turner.co.uk/produ...n/u30-bar-twin

Having said that, I did a stuart turner 1.8 bar pump for SWMBO's aunt
once, and that worked fine without any changes to the cylinder. The cold
cistern was in the loft about only about 6' higher than the cylinder.

I'll have to start collecting pump info. Any favourite ones, or ones to avoid?

Not used that many. Stuart turner always seem to get good reviews, and I
think quite a few in this group have had good results with them.




--
Cheers,

John.

/================================================== ===============\
| Internode Ltd - http://www.internode.co.uk |
|-----------------------------------------------------------------|
| John Rumm - john(at)internode(dot)co(dot)uk |
\================================================= ================/

On Sun, 30 Sep 2012 22:58:36 +0100, John Rumm wrote:

On 30/09/2012 22:38, Phil Addison wrote:

Sucking in air will be a function of the actual flow rate achieved surely? I can

Yes in the sense that if you are pumping into more flow resistance, the
required delivery rate to the pump will be less. The main issue is that
you are depending on gravity to feed the pump and so need as little flow
resistance there as possible.

appreciate problems with a big pump trying to work into a high resistance tho; but don't
the manufacturers give a flow vs head characteristic so one can predict the performance,
like the c/h circulators offer?

They do normally - e.g.:

http://www.stuart-turner.co.uk/produ...n/u30-bar-twin

That's a good chart, thanks, now I just need to figure out my pipe resistances + shower
resistance to draw the load line on it. Looking at a random Mira spec sheet its lacking
the corresponding flow vs pressure chart or any hint of resistance; just states inlet is
required to be maintained at 0.2 to 5 bar LOL. So if they are all like that choosing the
optimum* pump sounds a bit of a guessing game.

*Adequate but not too much pressure (excessive noise etc).

Having said that, I did a stuart turner 1.8 bar pump for SWMBO's aunt
once, and that worked fine without any changes to the cylinder. The cold
cistern was in the loft about only about 6' higher than the cylinder.

I'll have to start collecting pump info. Any favourite ones, or ones to avoid?

Not used that many. Stuart turner always seem to get good reviews, and I
think quite a few in this group have had good results with them.

--
Phil Addison

On 01/10/2012 12:07, Phil Addison wrote:
On Sun, 30 Sep 2012 22:58:36 +0100, John Rumm wrote:

On 30/09/2012 22:38, Phil Addison wrote:

appreciate problems with a big pump trying to work into a high resistance tho; but don't
the manufacturers give a flow vs head characteristic so one can predict the performance,
like the c/h circulators offer?

They do normally - e.g.:

http://www.stuart-turner.co.uk/produ...n/u30-bar-twin

That's a good chart, thanks, now I just need to figure out my pipe resistances + shower
resistance to draw the load line on it. Looking at a random Mira spec sheet its lacking
the corresponding flow vs pressure chart or any hint of resistance; just states inlet is
required to be maintained at 0.2 to 5 bar LOL. So if they are all like that choosing the
optimum* pump sounds a bit of a guessing game.

*Adequate but not too much pressure (excessive noise etc).

Depends really on what you want from a shower...

With most "normal" showers (i.e. not a soaker head, or something with
body jets), most of the flow resistance will be at the shower head
unless its miles from the pump, so you can mostly discount the pipe run
I would expect.

Reports from aforementioned aunt were favourable regarding the 1.8 bar
one. Although her sprogs said it was "much better" but could still do
with even more oomph (this may just reflect the fact they were not
paying for the water or heat!) IME by the time you reach 3 bar, then you
are comparable with most mains pressure showers. In my previous place,
we had about 3 bar from the mains through a combi, and that was a very
good shower - you did not really need full throttle on the controls. In
this place we have a slightly knackered Aqulisa power shower (knackered
in that the "power" bit has never worked, but the mixer section was ok).
I have just shifted that over to high pressure operation (3.5 bar), and
much to my relief it did not immediately spring a leak or fly apart. Tap
full open on that is getting on for excessive now.

None of them are particularly quiet - although its more of a problem for
the people not in the shower! Mounting them in such a way as to stop
them "sounding" through the building structure (most come with rubber
"tails" to make the final joint to the pipework to stop them shaking
that) helps. Possibly even screw them to a concrete slab, and then sit
that on some foam rubber.



--
Cheers,

John.

/================================================== ===============\
| Internode Ltd - http://www.internode.co.uk |
|-----------------------------------------------------------------|
| John Rumm - john(at)internode(dot)co(dot)uk |
\================================================= ================/