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

On Sep 20, 4:30 pm, 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....


Would you be worrying if six people (each weighing 80kg) stood on your
floor in three groups of two? That would give the same weight
distribution as the piano but you probably woul dnot even give it a
thought. Maybe nothing needs to be done.

Robert

Robert wrote:


Would you be worrying if six people (each weighing 80kg) stood on your
floor in three groups of two? That would give the same weight
distribution as the piano but you probably woul dnot even give it a
thought. Maybe nothing needs to be done.

Robert


Thanks and that was one of the scenarios we considered!

This is to do with protecting a very valuable item of ours and as it has
to be standing in the same place for years (because it cannot easily be
moved), I was asking whether the idea's I had put forward had any merit
or not.

If not, and while the floor is open, I would prefer to do the best thing.

As you say, maybe nothing needs done.

Steve

On Thu, 20 Sep 2007 16:15:03 +0000, Steve wrote:

Robert wrote:


Would you be worrying if six people (each weighing 80kg) stood on your
floor in three groups of two? That would give the same weight
distribution as the piano but you probably woul dnot even give it a
thought. Maybe nothing needs to be done.

Robert


Thanks and that was one of the scenarios we considered!

This is to do with protecting a very valuable item of ours and as it has
to be standing in the same place for years (because it cannot easily be
moved), I was asking whether the idea's I had put forward had any merit or
not.

If not, and while the floor is open, I would prefer to do the best thing.

As you say, maybe nothing needs done.

Steve

==================================
Google pictures suggest that it's on castors which in turn suggests very
localised loading. It would be worth considering some kind of load
spreader made from material other than wood which can't be
easily penetrated or indented by pressure.

Cic.
--
===================================
Using Ubuntu Linux
Windows shown the door
===================================

Cicero wrote:

==================================
Google pictures suggest that it's on castors which in turn suggests very
localised loading. It would be worth considering some kind of load
spreader made from material other than wood which can't be
easily penetrated or indented by pressure.

Cic.

Indeed, the load is on castors and that would amount to considerable
point load as you suggest. The piano is presently standing on castor
cups recommended by Steinway that spread out the load to 6" circles.
They are, I believe, made of some sort of plastic.

Thanks

Steve

In article , Steve
scribeth thus
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




Dunno about the stress .. but will it affect the sound;-?....







--
Tony Sayer

On Thu, 20 Sep 2007 16:33:38 UTC, tony sayer wrote:

In article , Steve
scribeth thus
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

Dunno about the stress .. but will it affect the sound;-?....

Depends if one uses gold plated, oxygen free cut nails! :-)


--
The information contained in this post is copyright the
poster, and specifically may not be published in, or used by
http://www.diybanter.com

Bob Eager wrote:
On Thu, 20 Sep 2007 16:33:38 UTC, tony sayer wrote:


Dunno about the stress .. but will it affect the sound;-?....

Depends if one uses gold plated, oxygen free cut nails! :-)


LOL Which are best...?

Steve

You probably have a very good idea where each foot of your grand will
be positioned.

You could consider independent masonry pillar supports topped with
timber plates pressing up against the underside of the floor boards at
these locations.

wrote:
You probably have a very good idea where each foot of your grand will
be positioned.

A very good idea! We have a triangle made from lengths of wood that show
us where the the piano will sit more or less exactly.

You could consider independent masonry pillar supports topped with
timber plates pressing up against the underside of the floor boards at
these locations.

This is something that I had considered. The existing sleeper walls seem
to be built on top of the rough floor concrete so extra support should
be easy to add as you suggest. I had it in mind to provide to provide
that additional support under the joists in these areas if necessary.

Thanks

Steve

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 :-)

Couldn't you play the mouth organ instead? :-)

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 built a deck for 2000kg hot tub last year. 6 x 2 joists at 12" centres
supported every 4'. Not a millimetre of movement!


--
Dave
The Medway Handyman
www.medwayhandyman.co.uk
01634 717930
07850 597257

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 built a deck for 2000kg hot tub last year. 6 x 2 joists at 12" centres
supported every 4'. Not a millimetre of movement!

Remember the depth cubed factor though - 6" is more than 3 times
stiffer than 4"

wrote:
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 built a deck for 2000kg hot tub last year. 6 x 2 joists at 12"
centres supported every 4'. Not a millimetre of movement!

Remember the depth cubed factor though - 6" is more than 3 times
stiffer than 4"

I didn't know that - where could I find out more?


--
Dave
The Medway Handyman
www.medwayhandyman.co.uk
01634 717930
07850 597257

The Medway Handyman wrote:
wrote:
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 built a deck for 2000kg hot tub last year. 6 x 2 joists at 12"
centres supported every 4'. Not a millimetre of movement!
Remember the depth cubed factor though - 6" is more than 3 times
stiffer than 4"

I didn't know that - where could I find out more?


Take an engineering degree.?

The Natural Philosopher wrote:
The Medway Handyman wrote:
wrote:
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 built a deck for 2000kg hot tub last year. 6 x 2 joists at 12"
centres supported every 4'. Not a millimetre of movement!
Remember the depth cubed factor though - 6" is more than 3 times
stiffer than 4"

I didn't know that - where could I find out more?


Take an engineering degree.?

Bit OTT for a handyman with a thirst for knowledge?


--
Dave
The Medway Handyman
www.medwayhandyman.co.uk
01634 717930
07850 597257

On Thu, 20 Sep 2007 20:33:51 GMT The Medway Handyman wrote :
Remember the depth cubed factor though - 6" is more than 3 times
stiffer than 4"

I didn't know that - where could I find out more?

Strength is proportional to Z = BD^2/6 for a rectangular section

Stiffness is proportional to I = BD^3/12

Most timber beam (joists, rafters) sizes are governed by deflection
limits rather than strength - you could drop most floor joist sizes
by 25mm without any risk of the floor collapsing but it would be
unacceptably bouncy.

Compare (imperial units more manageable)

Strength: 8 x 2 Z = 21.3 7 x 2 Z = 16.3 - 23% less strength
(but probably still within limits for most floors)

Stiffness I = 85.3 I = 57.2 - 33% less stiff
(= 50% more deflection for same load)

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

Tony Bryer wrote:
On Thu, 20 Sep 2007 20:33:51 GMT The Medway Handyman wrote :
Remember the depth cubed factor though - 6" is more than 3 times
stiffer than 4"

I didn't know that - where could I find out more?

Strength is proportional to Z = BD^2/6 for a rectangular section

Stiffness is proportional to I = BD^3/12

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


--
Dave
The Medway Handyman
www.medwayhandyman.co.uk
01634 717930
07850 597257

Tony Bryer wrote:
On Thu, 20 Sep 2007 20:33:51 GMT The Medway Handyman wrote :
Remember the depth cubed factor though - 6" is more than 3 times
stiffer than 4"
I didn't know that - where could I find out more?

Strength is proportional to Z = BD^2/6 for a rectangular section

Stiffness is proportional to I = BD^3/12

Most timber beam (joists, rafters) sizes are governed by deflection
limits rather than strength - you could drop most floor joist sizes
by 25mm without any risk of the floor collapsing but it would be
unacceptably bouncy.

Compare (imperial units more manageable)

Strength: 8 x 2 Z = 21.3 7 x 2 Z = 16.3 - 23% less strength
(but probably still within limits for most floors)

Stiffness I = 85.3 I = 57.2 - 33% less stiff
(= 50% more deflection for same load)

Thanks for that Tony. I will download the demo and have a play with
various options.

Steve

"Steve" wrote in message

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



Metal 1/4" x 3" plate both sides of the intended joist

"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 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

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 |
\================================================= ================/

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