Steve wrote:


I have downloaded the software from Tony's website and had a quick play. But it is
clear that I need to follow the advice on there and print out the instructions!

I setup a beam with two loading entries: one "U" (i.e. uniform)
specified as 0.8, and one "P" (point) at .7m from distance, and a load
of 1.6kN.

So thanks also to Tony for generously making the software available to non
professionals like myself.

Yup, I will second that.

Coming back to the joists, I had a gut feeling that deflection would be
more than desired and your results back this up although you have quite
rightly taken the worst case with the load in the centre of the span. In
our case most of the load will be near to a sleeper wall for each leg.
But I would rather be conservative and use worst case!

That also assumed the leg directly over one joist - if it were to the
side a little the the load would be more spread between two (I did leave
the load sharing set to 2 however)

One idea was to double the joists up i.e. putting extra joists in
between but in the areas of high load to have double joists joined, but
I had thought of glueing them together and bolting through the neutral
access. Any problems with glueing and bolting?

I would be a little wary of bolting a joist that is only 100mm high.
Your standard 12mm bolts would hence be taking out over 10% of the joist
depth at the point.

You could glue, or use the spiked timber connectors on the bolts if
going that route. I would have though that just nailing the joists side
by side would be enough in this circumstance.

I also had an extension to this idea...I thought of cutting 8" strips of
18mm WBP, glueing two together and then sandwiching that between two
joists, all glued and bolted. In effect a 'T' beam. Obviously the ply
can't extend the total length because of the sleeper walls but that
would probably not matter as shear is unlikely to be a problem, I think.
Any comments on this idea?

Doable, but possibly overkill. If you wanted a beam stronger than a pair
of timbers side by side, then the next option would usually be a flitch
beam[1] (i.e. a pair of beams with a steel plate sandwiched between
them, and bolted together). Not sure how realistic that is on only 4" of
depth though.



[1] Example 8mm steel plate flitch (with red passivated coating):

http://www.internode.co.uk/loft/images/flitch.jpg



--
Cheers,

John.

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

Steve wrote:

One idea was to double the joists up i.e. putting extra joists in
between but in the areas of high load to have double joists joined, but
I had thought of glueing them together and bolting through the neutral
access. Any problems with glueing and bolting?

I'm sorry but access was not what I meant to type!

Neutral axis

Steve

Bolting through the neutral axis will have negligible effect on the
stiffness of the beam
A 12 mm hole is about an eighth of your depth, Stiffness proportional to
depth cubed, so about 0.2% reduction..
There is no need to glue the beams together (as confirmed by my structural
engineer)


"Steve" wrote in message
.uk...
Steve wrote:

One idea was to double the joists up i.e. putting extra joists in between
but in the areas of high load to have double joists joined, but I had
thought of glueing them together and bolting through the neutral access.
Any problems with glueing and bolting?

I'm sorry but access was not what I meant to type!

Neutral axis

John Rumm wrote:

Coming back to the joists, I had a gut feeling that deflection would
be more than desired and your results back this up although you have
quite rightly taken the worst case with the load in the centre of the
span. In our case most of the load will be near to a sleeper wall for
each leg. But I would rather be conservative and use worst case!

That also assumed the leg directly over one joist - if it were to the
side a little the the load would be more spread between two (I did leave
the load sharing set to 2 however)

No problem, you have confirmed what I thought and unless one is a
structural engineer it is better to err on the side of caution.

One idea was to double the joists up i.e. putting extra joists in
between but in the areas of high load to have double joists joined,
but I had thought of glueing them together and bolting through the
neutral access. Any problems with glueing and bolting?

I would be a little wary of bolting a joist that is only 100mm high.
Your standard 12mm bolts would hence be taking out over 10% of the joist
depth at the point.

Yes, I see that but wouldn't the fact that the beam was drilled only in
the neutral axis i.e. along the centre where I believe that the beam was
neither under compression or expansion make this OK? I would also clamp
the edges tightly whilst the glue sets.

You could glue, or use the spiked timber connectors on the bolts if
going that route. I would have though that just nailing the joists side
by side would be enough in this circumstance.

You are right. I just have an inherent distrust of nails, even big ones!

I also had an extension to this idea...I thought of cutting 8" strips
of 18mm WBP, glueing two together and then sandwiching that between
two joists, all glued and bolted. In effect a 'T' beam. Obviously the
ply can't extend the total length because of the sleeper walls but
that would probably not matter as shear is unlikely to be a problem, I
think. Any comments on this idea?

Doable, but possibly overkill. If you wanted a beam stronger than a pair
of timbers side by side, then the next option would usually be a flitch
beam[1] (i.e. a pair of beams with a steel plate sandwiched between
them, and bolted together). Not sure how realistic that is on only 4" of
depth though.

I did not know about flitch beams. Maybe my thoughts about deep depths
of plywood sandwiched between the joists are my primitive way of
re-inventing the wheel :-) However that has got me thinking that this
might be the neatest, most elegant and best solution. Presumably a steel
stockholder would cut and 'passivate' them for me.



[1] Example 8mm steel plate flitch (with red passivated coating):

http://www.internode.co.uk/loft/images/flitch.jpg

Yes, I see it there - what does it have to support?

Thanks again John.

Steve

"Steve" wrote in message
. uk...
Time soon to put new floor down in lounge, but it is a bit more involved.

This floor has to support a substantial dead weight or two - A Steinway
Concert Grand Piano that weighs in at 480kg, or about half a tonne. The
weight is, according to Steinway, evenly distributed over the three legs
i.e. 160kg per leg.

The other dead load is a lighter but still heavy - Boston upright piano
that is probably half the weight or less and with weight on four feet,
although centred on a much smaller overall area. .

The remaining "live" load will be furniture etc. - normal things :-)

The existing joists are 4" by 2" and are at present supported by sleeper
walls at 5 foot centres, the spacing between joists is 10" with no
noggins.

I plan to increase the number of joists by about two, depending on
arranging things to suit the Caberboards that I think will do the job.
Running double joists where the dead weight will be centred.

This will, obviously, make it harder for noggins if they are needed to be
fitted, but the close spacing between joists should make them unnecessary
I think?

Am I on the right track here? Any ideas or information would be most
welcome before I do it and find that our beloved piano has crashed through
the floor!

Thanks

Steve
Hi,

You could of course "Test" your floor before engaging in all this work,
without any Pianos being involved.

You get 7 adult men, who will weigh about 14 stone (75Kg each, 525Kg total),
to stand where the heavier piano is to be placed, and 3 adult men (total
225Kg) to stand where the lighter piano is to stand.

If the floor survives this test without any groaning, then you can get them
to jump up and down to give the floor a shock load.

If you are worried about the point loading then maybe you need to fit steel
plates to the floor to spread the load.

Ian.

"Ian G" wrote in message
...
18mm ply glued and screwed to the top of the joists (instead of unglued
chipboard) , forming a T beam was a solution proposed by a structural
engineer and adopted by me when I did a loft conversion some years ago. We
didn't put a piano up there, but the purchasers of the house did install a
water bed and there have been no adverse reports from neighbours whom I
have remained in contact with. The increase in strength over the unglued
floor was impressive, confirming in practice what the Moment of Inertia
calculations indicated. We were able to jump up and down on the floor and
detect very little spring.

I would expect it to be even better if you fix a steel plate to the bottom
and ply to the top.
Steel is better in tension.
Just fixing a 3mm steel plate to either side of the joists will make a huge
difference as the wood stops the plate from warping and the 4" depth of
steel doesn't bend much. My conservatory roof is supported in a similar way
by ally strips inserted in channels in the plastic and I can walk on it and
I am not thin.

On Thu, 20 Sep 2007 23:08:32 GMT, "The Medway Handyman"
wrote:

Ok great, so what do Z, B, D & I stand for?

Boinggg said ZBDI - time for bed...

Geo

In article , Steve
scribeth thus
tony sayer wrote:
BTW you can get some nice electronic pianos these days that play like
the real thing and don't need maintenance every six months, take up less
space and are cheap(er).
Tell my wife ;-) We did have a Yamaha electronic piano for several years
but even to my untrained ear it was not a touch on a proper piano. A
concert grand is in a different league yet again.

Steve


No comparison!..

Lucky you having one of them in your living room, and someone who knows
how to drive it)

She is an amazing woman. Carol originally trained as a concert pianist
in Edinburgh and that is where she fell in love with this actual piano
that was brand new then (c.1979). As a keen student and with a new piano
that needed to be 'broken-in', she was allowed to play it whenever it
was not in use. Apparently, she made a resolve that one day she would
own it. She gave up music, I'm not quite sure why, and learnt to fly
instead.


Nowadays she is an airline pilot.

Very interesting .. could I have you e-mail addy please?

Mail me at I'd be obliged...

cheers

However, she never could never get this particular piano out of her mind
and a couple of years ago had the urge to find out what had become of
it. My suggestions that it would have been sold on by now were brushed
aside and she started making enquiries. Blimey! it was in Steinway's
showroom in London, refurbished and for sale! I won't say how much it
cost but it was a lot of money.

The next day, or it might have been the day after, we were on a train to
London and she bought it. We had nowhere to put it in a ground floor
flat! Her sister Elaine, also a concert pianist and piano teacher,
kindly agreed to give it a home near Glasgow, in her new extension.
Elaine has fallen in love with it too and now has plans to get one of
her own.

When I finish the floor in our new house it will be making the long
journey South to Crawley to be finally and fully reunited with Carol. A
dream that slowly is coming true!

Apart from the fantastic sound when I get the chance to hear it, I just
love to look inside it and marvel at the workmanship and incredible
engineering.

Indeed just be careful of the sonic properties of the floor. I'd just
double up a few joists, don't reckon steel beams etc are really called
for...

Steve




--
Tony Sayer

Steve wrote:

Yes, I see that but wouldn't the fact that the beam was drilled only in
the neutral axis i.e. along the centre where I believe that the beam was
neither under compression or expansion make this OK? I would also clamp
the edges tightly whilst the glue sets.

you have to be a little careful where you drill - i.e. not to close to
the ends or you risk allowing the beam to split.

You are right. I just have an inherent distrust of nails, even big ones!

Plenty of houses have stood for hundreds of years held together by
little else. ;-)

Doable, but possibly overkill. If you wanted a beam stronger than a
pair of timbers side by side, then the next option would usually be a
flitch beam[1] (i.e. a pair of beams with a steel plate sandwiched
between them, and bolted together). Not sure how realistic that is on
only 4" of depth though.

I did not know about flitch beams. Maybe my thoughts about deep depths
of plywood sandwiched between the joists are my primitive way of
re-inventing the wheel :-) However that has got me thinking that this
might be the neatest, most elegant and best solution. Presumably a steel
stockholder would cut and 'passivate' them for me.

Indeed they will - they will drill them for you as well. Superbeam will
model them for you as well.

[1] Example 8mm steel plate flitch (with red passivated coating):

http://www.internode.co.uk/loft/images/flitch.jpg

Yes, I see it there - what does it have to support?

The one in the photo was I believe "E":

http://www.internode.co.uk/temp/beam-layout.gif

Which as you can see gets a share of the load of pretty much everything
at the front of the loft, including the previously pictured dwarf wall.

So 0.8kN/m uniform load from the floor, a 5.7kN point load at 0.7m from
beam F (stringer that carried the main front floor joists - present
because getting at the existing lintle would have been too difficult),
and a 11kN point load at 2.8m from beam C (triple joist) that carried
two sets of floor joists, and a share of at least three partition
walls.... oh and a bit of roof.

So all in all about a nominal 20kN or two tonnes in total. The centre
span deflection was calculated at just under 9mm.

In context:

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


--
Cheers,

John.

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

Ian G wrote:
Bolting through the neutral axis will have negligible effect on the
stiffness of the beam
A 12 mm hole is about an eighth of your depth, Stiffness proportional to
depth cubed, so about 0.2% reduction..
There is no need to glue the beams together (as confirmed by my structural
engineer)

You can stick these on each bolt between the beams:

http://www.screwfix.com/sfd/i/cat/50/p1704550_x.jpg

(and flat plate washers either side)


--
Cheers,

John.

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

Ian French wrote:


Am I on the right track here? Any ideas or information would be most
welcome before I do it and find that our beloved piano has crashed through
the floor!

Thanks

Steve
Hi,

You could of course "Test" your floor before engaging in all this work,
without any Pianos being involved.

I think that there is definitely some strengthening to be done.

You get 7 adult men, who will weigh about 14 stone (75Kg each, 525Kg total),
to stand where the heavier piano is to be placed, and 3 adult men (total
225Kg) to stand where the lighter piano is to stand.

Our original plan to test the floor was to fill three 200 litre water
butts to full in the strategic positions and then us and friends to
jump up and down to see if the floor failed! This plan fell through,
sorry!, once I started taking the floor up and found that it, most
probably, would have failed catastrophically due to the poor state that
the floor was in and also a lot of past bodges that needed attention.

If the floor survives this test without any groaning, then you can get them
to jump up and down to give the floor a shock load.

If you are worried about the point loading then maybe you need to fit steel
plates to the floor to spread the load.

The point loading is a worry but with the proper cups under the castors
and stiffened joists this does not seem to be so much of a worry as
absolute strength.

Steve

John Rumm wrote:
Steve wrote:

Yes, I see that but wouldn't the fact that the beam was drilled only
in the neutral axis i.e. along the centre where I believe that the
beam was neither under compression or expansion make this OK? I would
also clamp the edges tightly whilst the glue sets.

you have to be a little careful where you drill - i.e. not to close to
the ends or you risk allowing the beam to split.

You are right. I just have an inherent distrust of nails, even big ones!

Plenty of houses have stood for hundreds of years held together by
little else. ;-)

Doable, but possibly overkill. If you wanted a beam stronger than a
pair of timbers side by side, then the next option would usually be a
flitch beam[1] (i.e. a pair of beams with a steel plate sandwiched
between them, and bolted together). Not sure how realistic that is on
only 4" of depth though.

I did not know about flitch beams. Maybe my thoughts about deep depths
of plywood sandwiched between the joists are my primitive way of
re-inventing the wheel :-) However that has got me thinking that this
might be the neatest, most elegant and best solution. Presumably a
steel stockholder would cut and 'passivate' them for me.

Indeed they will - they will drill them for you as well. Superbeam will
model them for you as well.

[1] Example 8mm steel plate flitch (with red passivated coating):

http://www.internode.co.uk/loft/images/flitch.jpg

Yes, I see it there - what does it have to support?

The one in the photo was I believe "E":

http://www.internode.co.uk/temp/beam-layout.gif

Which as you can see gets a share of the load of pretty much everything
at the front of the loft, including the previously pictured dwarf wall.

So 0.8kN/m uniform load from the floor, a 5.7kN point load at 0.7m from
beam F (stringer that carried the main front floor joists - present
because getting at the existing lintle would have been too difficult),
and a 11kN point load at 2.8m from beam C (triple joist) that carried
two sets of floor joists, and a share of at least three partition
walls.... oh and a bit of roof.

So all in all about a nominal 20kN or two tonnes in total. The centre
span deflection was calculated at just under 9mm.

In context:

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


Wow! Thanks for that John. I don't know why I have not visited your page
before. Absolutely fascinating and clear straightforward information but
with your knowledge clearly showing through . Bookmarked and when I have
the time, I will be going through it all to get ideas for further
projects! Tee Hee - expect further questions!

Steve

Steve wrote:

Wow! Thanks for that John. I don't know why I have not visited your page
before. Absolutely fascinating and clear straightforward information but
with your knowledge clearly showing through . Bookmarked and when I have
the time, I will be going through it all to get ideas for further
projects! Tee Hee - expect further questions!

Beware that some of the planing and building regs related information is
now out of date, and other changes are afoot.

(hence if you are planning a conversion - start now, it will be harder
later!)

--
Cheers,

John.

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

On 20 Sep, 16:30, Steve wrote:
Time soon to put new floor down in lounge, but it is a bit more involved.

This floor has to support a substantial dead weight or two - A Steinway
Concert Grand Piano that weighs in at 480kg, or about half a tonne. The
weight is, according to Steinway, evenly distributed over the three legs
i.e. 160kg per leg.

The other dead load is a lighter but still heavy - Boston upright piano
that is probably half the weight or less and with weight on four feet,
although centred on a much smaller overall area. .

The remaining "live" load will be furniture etc. - normal things :-)

The existing joists are 4" by 2" and are at present supported by sleeper
walls at 5 foot centres, the spacing between joists is 10" with no noggins.

I plan to increase the number of joists by about two, depending on
arranging things to suit the Caberboards that I think will do the job.
Running double joists where the dead weight will be centred.

This will, obviously, make it harder for noggins if they are needed to
be fitted, but the close spacing between joists should make them
unnecessary I think?

Am I on the right track here? Any ideas or information would be most
welcome before I do it and find that our beloved piano has crashed
through the floor!

Thanks

Steve

Dear Steve
I suspect I am probably the man to help you here as I have a degree in
timber engineering (ICST 1975 Civ Eng Dept) and have spent the last 30
plus years working on such floors in a practical fashion.
No one in the group has taken into account a factor in the design of
timber floors called "Duration of Load". (in essence were you to load
a beam say for a fraction of a second it would take 130% of its (so
called) maximum stress (derived from 5 min tests to destruction) of
100% by definition and conversely IF you were to load it to as little
as 60% of its "maximum" it may well fail though it may take some years
so to do.
This is particularly true if the timber is green and goes through the
fibre saturation point under load and vast proportional creeps are
manifest...
So you need to take that into account and the Codes of Practice do so.

On a practical basis you need to do the following

carefully identify and lift up the floorboards (marking with pencil so
you know where they come from) the board in the areas of the pianos
and beyond the next wall plates - staggering the cuts (if needed) to
alternate joists and cutting on the joists. Use a right angle square
pencil and ~Fien multi master to get neat cuts or lift all the board
Once you have access to the sub floor (check ventitlation whilst you
are at it) check the structure of the sleeper walls and that they are
sound enought and founded well - improve if needed
Consider at this point if it is worth it putting in an addtional
sleeper wall - the closer to you point loads the better
consider putting in INDIVIDUAL supports to the concrete as suggested
by others
whilst on about the concrete consider a trial pit remote from the
load to see how thick it is and if it is ok fine
If not spread the load on the point supports with 4" of new concrete
with 142 mesh so it is over the old concrete
I guess about 1 m square for each corner would be more than ample but
if in doubt calculate (engineer)

Next simply run more 4" joists alongside the old ones on the existing
and new wall plates such as to cover the 6" of your spreader cicles -
that is only likely to be 3 or at most 4 new joists between the two
wall plates for each of the legs and with a bit of luck two will
coincide!

4 x 2" does not cost much and it is not likely that you will need
much more than 8' for each set of 3

If you are fussy screw or nail them together so you get a shared
effect and avoid individual variations in strenth becoming manifest

lay floor boards back down - I would use brass screws but I am fussy

Any problems come back to me
If you can scan and send me a plan locating point loads and existing
wps I will work out a rough idea of where to go should you so want on
our pro bono terms - ie FOC - you indemnify us!
Chris

wrote:

No one in the group has taken into account a factor in the design of
timber floors called "Duration of Load". (in essence were you to load

No need to worry, we did - at least implicitly...

I used a loading duration of 1.0 (long term) on the calculation I did
with superbeam. ;-)




--
Cheers,

John.

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

On Sep 21, 8:56 am, Mogga wrote:
On Fri, 21 Sep 2007 00:54:33 -0700, Robert
wrote:



In fact I face a related problem. I plan to put an upright piano into
our 1960s house and the position it will occupy means that all the
weight will be one two joists running parallelto the piano. the
joists in the house are inadequate; I have alrady had problems with
the floor moving when I piled a lot of books on it, so I plan to add

How many books? Thousands?

Yes, probably about two thousand books.

Robert

wrote:
On 20 Sep, 16:30, Steve wrote:
Time soon to put new floor down in lounge, but it is a bit more involved.

This floor has to support a substantial dead weight or two - A Steinway
Concert Grand Piano that weighs in at 480kg, or about half a tonne. The
weight is, according to Steinway, evenly distributed over the three legs
i.e. 160kg per leg.

The other dead load is a lighter but still heavy - Boston upright piano
that is probably half the weight or less and with weight on four feet,
although centred on a much smaller overall area. .

The remaining "live" load will be furniture etc. - normal things :-)

The existing joists are 4" by 2" and are at present supported by sleeper
walls at 5 foot centres, the spacing between joists is 10" with no noggins.

I plan to increase the number of joists by about two, depending on
arranging things to suit the Caberboards that I think will do the job.
Running double joists where the dead weight will be centred.

This will, obviously, make it harder for noggins if they are needed to
be fitted, but the close spacing between joists should make them
unnecessary I think?

Am I on the right track here? Any ideas or information would be most
welcome before I do it and find that our beloved piano has crashed
through the floor!

Thanks

Steve

Dear Steve
I suspect I am probably the man to help you here as I have a degree in
timber engineering (ICST 1975 Civ Eng Dept) and have spent the last 30
plus years working on such floors in a practical fashion.
No one in the group has taken into account a factor in the design of
timber floors called "Duration of Load". (in essence were you to load
a beam say for a fraction of a second it would take 130% of its (so
called) maximum stress (derived from 5 min tests to destruction) of
100% by definition and conversely IF you were to load it to as little
as 60% of its "maximum" it may well fail though it may take some years
so to do.
This is particularly true if the timber is green and goes through the
fibre saturation point under load and vast proportional creeps are
manifest...
So you need to take that into account and the Codes of Practice do so.

Thanks Chris and I apologise for the delay in replying - we had a bit of
a break from floors and the computer whilst carol was home!

I had sort of said about the Duration of Load when I mentioned that the
piano would not be moved from its place and John has taken that into
account but it is something that has worried me as much as the absolute
weight.

On a practical basis you need to do the following

carefully identify and lift up the floorboards (marking with pencil so
you know where they come from) the board in the areas of the pianos
and beyond the next wall plates - staggering the cuts (if needed) to
alternate joists and cutting on the joists. Use a right angle square
pencil and ~Fien multi master to get neat cuts or lift all the board
Once you have access to the sub floor (check ventitlation whilst you
are at it) check the structure of the sleeper walls and that they are
sound enought and founded well - improve if needed

Yes we have ripped up all of the floor as a lot of floorboards were
damaged or left unsupported after plumbing and electrical work in the
past. I am adding additional airbricks to improve ventilation. It used
to be two rooms, with a central fireplace that was demolished, we think,
about twenty years ago. Whoever did it put half of the rubble under the
floor and left the joists over where the fireplace was supported on
rubble without any dpc. So I am going to have work to do here too!

Consider at this point if it is worth it putting in an addtional
sleeper wall - the closer to you point loads the better
consider putting in INDIVIDUAL supports to the concrete as suggested
by others
whilst on about the concrete consider a trial pit remote from the
load to see how thick it is and if it is ok fine
If not spread the load on the point supports with 4" of new concrete
with 142 mesh so it is over the old concrete
I guess about 1 m square for each corner would be more than ample but
if in doubt calculate (engineer)

Next simply run more 4" joists alongside the old ones on the existing
and new wall plates such as to cover the 6" of your spreader cicles -
that is only likely to be 3 or at most 4 new joists between the two
wall plates for each of the legs and with a bit of luck two will
coincide!

4 x 2" does not cost much and it is not likely that you will need
much more than 8' for each set of 3

If you are fussy screw or nail them together so you get a shared
effect and avoid individual variations in strenth becoming manifest

lay floor boards back down - I would use brass screws but I am fussy

Any problems come back to me

Thanks again, some very good ideas there. I particularly like the idea
of the point support as only one of the legs would be mid-span on a
joist - the others are close to a sleeper wall and just the paralleled
or tripled joists would seem sufficient. So this is the way I am
planning to go.


If you can scan and send me a plan locating point loads and existing
wps I will work out a rough idea of where to go should you so want on
our pro bono terms - ie FOC - you indemnify us!
Chris


That is a very kind offer - thanks, hopefully though with an additional
support as you suggest and the extra joists I think it will be OK. But
if I do run into any problems, I will get back to you!

Cheers

Steve

On Sep 21, 11:07 am, "dennis@home"
wrote:
"Steve" wrote in message

. uk...

The finished floor will be thickened by a further 15mm as we have T&G
engineered oak floor to go on top of the Caberboard. This should help with
the point loading but will not help much with any bounce if there is any.

Metal plates would be a good idea but would be difficult to implement with
the oak floor.

What will stop the piano marking the floor?
160kg on most castors is going to put grooves in a wooden floor IME.



It is unlikely that the piano would be moved from the spot. There just
isn't the room!

I wondered what the acoustics will be like and if it will hold tune if the
floor sags unevenly.
Is there a mechanism to level the piano or doesn't it matter?

Have you considered casting some concrete pads under the floor and building
some small supporting piers in the correct places?
It is probably easy if you are going to cover the floor.

BTW you can get some nice electronic pianos these days that play like the
real thing and don't need maintenance every six months, take up less space
and are cheap(er).

....and you can set the switch so it sounds exactly like a Steinway. I
am trying hard to persuade myself that I want one of these (rather
than real piano) because of its ability to use headphones and not
disturb others. But I am not persuaded.

Robert

RobertL wrote:

...and you can set the switch so it sounds exactly like a Steinway. I
am trying hard to persuade myself that I want one of these (rather
than real piano) because of its ability to use headphones and not
disturb others. But I am not persuaded.

LOL! No, nor are we :-)

Steve

"RobertL" wrote in message
oups.com...

BTW you can get some nice electronic pianos these days that play like the
real thing and don't need maintenance every six months, take up less
space
and are cheap(er).

...and you can set the switch so it sounds exactly like a Steinway. I
am trying hard to persuade myself that I want one of these (rather
than real piano) because of its ability to use headphones and not
disturb others. But I am not persuaded.

The Yamaha baby grand is supposed to be good.. I have never seen one myself.

My daughter has to put up with a cheap Korg piano and we still struggle for
space.
It sounds OK but its better if I connect my Yamaha synthbox to its MIDI.
There are much better synths about including an add in card for mine that is
supposed to be extremely good but I doubt if I could tell.

"Steve" wrote in message
news
RobertL wrote:

...and you can set the switch so it sounds exactly like a Steinway. I
am trying hard to persuade myself that I want one of these (rather
than real piano) because of its ability to use headphones and not
disturb others. But I am not persuaded.

LOL! No, nor are we :-)

As you suffer from someone who is pitch perfect I can see you having
problems..
do you have your grand tuned frequently so it sounds excellent for a week or
two a month
or
do you buy an electronic one that sounds OK, but not excellent, all the
time?

I went for the electronic one and it fits in the car too.

On 21 Sep, 17:30, "Ian G" wrote:
The ply was glued and screwed to the top of the joists substituting for, but
perhaps a couple of millimetres less deep than the more conventional
chipboard. I think a difficulty in sandwiching between joists might be in
maintaining the strength at the joints. Presumably glue & screw battens to
the joists then glue & screw your inserts to these battens?
Now if you could somehow get access to the underside of the joists with
sheet plywood and complete the box, you are talking about a MAJOR increase
in stiffness ;-)

Kerching !! how about making up a timber box beams? A pair of new joists
say 65mm deep by 50mm wide. glue & screw 18mm ply top & bottom & slot into
inter joist space screwing through existing joists into new ones, or resting

Does anybody (eg Tony) know if Superbeam will model such a system?

I'm still working on my shed, and Superbeam tells me that the 2x3
rafters at 2' centres aren't good enough to hold a heavy green roof.
On the other hand, if I glue and screw 18mm Stirling board on top that
helps quite a bit, and if I fit some thin ply underneath, that would
help even more.

On 27 Sep, 14:00, Tony Bryer wrote:
On Thu, 27 Sep 2007 04:45:59 -0700 Martin Bonner wrote :

Does anybody (eg Tony) know if Superbeam will model such a system?

I'm still working on my shed, and Superbeam tells me that the 2x3
rafters at 2' centres aren't good enough to hold a heavy green roof.

Without checking out the calcs (am drowning under work ATM), most
timber calculations result in the member being sized to keep the
deflection within limits, and the standard limit (0.003 x span) is
really to do with preventing damage to plaster finishes and stopping
floors feeling uncomfortably springy (whilst being safe). If the
calculation shows the applied bending stress as being less than the
permissible then all should be OK.

Actually the stress was a problem with 45x70mm beams (the actual
size), but was OK with 45x88mm (assuming the OSB just adds 18mm to the
thickness of the beam). I /think/ I can get away with that.
a) I know that OSB will not be as strong in compression as C16
timber.
b) I am relying on the screw + glue transferring the entire load
-but-
c) I am not really adding a 45mm strip of OSB - I am adding a 590mm of
the stuff (no, I don't think that will be 13 times as strong as a 45mm
strip; but it ought to bring it up to C16 levels).

What I was hoping was that SuperBeam would be able to model such a
composite structure - but I suppose it isn't a fully blown finite
element modelling package (It certainly isn't priced like one ...
though you wouldn't know that from the support service :-)

On Thu, 27 Sep 2007 04:45:59 -0700 Martin Bonner wrote :
Does anybody (eg Tony) know if Superbeam will model such a system?

I'm still working on my shed, and Superbeam tells me that the 2x3
rafters at 2' centres aren't good enough to hold a heavy green roof.

Without checking out the calcs (am drowning under work ATM), most
timber calculations result in the member being sized to keep the
deflection within limits, and the standard limit (0.003 x span) is
really to do with preventing damage to plaster finishes and stopping
floors feeling uncomfortably springy (whilst being safe). If the
calculation shows the applied bending stress as being less than the
permissible then all should be OK.

--
Tony Bryer SDA UK 'Software to build on' http://www.sda.co.uk

"Martin Bonner" wrote in message
ups.com...

On the other hand, if I glue and screw 18mm Stirling board on top that
helps quite a bit, and if I fit some thin ply underneath, that would
help even more.


I think I can confirm that from experience..
I have just built a shed and used 18mm ply glued to 25mm polystyrene glued
to 6mm WBP for the floor.
It is very stiff even before putting it onto the 4x2 joists 5 foot span.
Once its on the joists at 20" centres myself, my wife and my daughter can
jump up and down on it and it hardly moves.
I suspect it was a bit OTT.

On Thu, 27 Sep 2007 05:37:20 -0700 Martin Bonner wrote :
What I was hoping was that SuperBeam would be able to model such a
composite structure - but I suppose it isn't a fully blown finite
element modelling package (It certainly isn't priced like one ...
though you wouldn't know that from the support service :-)

Afraid not since (a) I'm not that clever; and (b) over the years there
have been lots of requests for enhancements that would destroy what it
is - a nice simple package for nice simple beams.

--
Tony Bryer SDA UK 'Software to build on' http://www.sda.co.uk