Hi,

I've removed an interior block wall which was supporting some joists
and installed a steel beam at joist level to support the floors and
the interior wall above. I had to cut the joists 1-2" short of the
beam in order to fit it at the level of the joists. What is the best
way to extend the joists into the web of the beam? I was thinking of
lap jointing short (i.e., 60cm) lengths of timber (7x1.5) which would
be screwed and glued to the existing joists.

Is this method of fixing sufficiently strong, or should I be using
bolts & toothed plate timber connectors? Is there a better way?

Niall

On 13 Nov, 22:10, Niall Smart wrote:
Hi,

I've removed an interior block wall which was supporting some joists
and installed a steel beam at joist level to support the floors and
the interior wall above. I had to cut the joists 1-2" short of the
beam in order to fit it at the level of the joists. What is the best
way to extend the joists into the web of the beam? I was thinking of
lap jointing short (i.e., 60cm) lengths of timber (7x1.5) which would
be screwed and glued to the existing joists.

Is this method of fixing sufficiently strong, or should I be using
bolts & toothed plate timber connectors? Is there a better way?

Niall

You don't extend the joists.

Either hang the joists off the top of the beam with hangers, or if
possible fit a timber section into the beam web and fix hangers to
this to hang the joists off

dg

In article om,
dg writes:
You don't extend the joists.

Either hang the joists off the top of the beam with hangers, or if
possible fit a timber section into the beam web and fix hangers to
this to hang the joists off

Been watching a shop being rebuilt and this is exactly what
they've done. The timber fitted into the web is bolted through
the middle of the timber and beam at regular intervals.

--
Andrew Gabriel
[email address is not usable -- followup in the newsgroup]

On 13 Nov, 22:10, Niall Smart wrote:
Hi,

I've removed an interior block wall which was supporting some joists
and installed a steel beam at joist level to support the floors and
the interior wall above. I had to cut the joists 1-2" short of the
beam in order to fit it at the level of the joists. What is the best
way to extend the joists into the web of the beam? I was thinking of
lap jointing short (i.e., 60cm) lengths of timber (7x1.5) which would
be screwed and glued to the existing joists.

Is this method of fixing sufficiently strong, or should I be using
bolts & toothed plate timber connectors? Is there a better way?

Niall

Dear Niall
As I understand your post - the steel is already in place and about
50mm short of the flange of the beam and so none of the suggestions
made to date are, in fact, feasible under the circumstances.
Had I been you, I would not have cut the joists in the first place in
order to put in the RSJ but would instead have fitted two RSAs back to
back with pipe spacers in between such as one of the RSAs either took
up the ends of your short joists or better still - as cited above - a
shaped timber "plate" set within the flange of the RSA such as to use
a Speedy type timber to timber joist hanger with square twisted (high
withdrawal resistant) nails.
OK too late for that this time so you need to make a decision between
your suggestions of glue and screw or double-sided tooth plate
connectors
Technically you need to get calculated the mainly shear forces at this
point in the beam and determine if a glued and screwed joint complies
with what used to be CP112 (sorry I did my engineering in 1976). My
instinct is that IF the glue and screws are right that you could get
away with it.
My advice is to get an engineer to calculate. That said, if you elect
not to follow that advice and are going to glue it then use a UF or
Resorcinol type structural glue - the sort used in Glulam beams.
Supplement this with decent screws at calculated centres. How about a
compromise and go for coach screws with 2" plate washers, double
sided connectors amd use the conventional edge end and spacing
distances which I would guess on a 7" timber will be 50 mm from the
edge, 75mm from the end and not less than say 150mm spacing between
screws. You could get three sets in staggered lines along a 7 " timber
- one 50 from the top - one 50 from the bottom both in line vertically
and one staggered in the neutral axis.

Alternatively use four bolts in a rectangular pattern 50mm edge 75 mm
end and say 350 mm spacing should see you right

Chris G

I've removed an interior block wall which was supporting some joists
and installed a steel beam at joist level to support the floors and
the interior wall above. I had to cut the joists 1-2" short of the
beam in order to fit it at the level of the joists.

[cut]

As I understand your post - the steel is already in place and about
50mm short of the flange of the beam and so none of the suggestions
made to date are, in fact, feasible under the circumstances.

Unfortunately not A bit more forward planning and accurate
cutting would have paid dividends here.

Had I been you, I would not have cut the joists in the first place in
order to put in the RSJ but would instead have fitted two RSAs back to
back with pipe spacers in between such as one of the RSAs either took
up the ends of your short joists or better still - as cited above - a
shaped timber "plate" set within the flange of the RSA such as to use
a Speedy type timber to timberjoisthanger with square twisted (high
withdrawal resistant) nails.

Timber set into the web of the RSJ would have been an option, I could
not have used RSA as there is a wall above to support. It would have
been tight to set the beam in, as presumably the joists would need to
be within 10mm of the flange to ensure a decent footing on the joist
hangars.

[snip]

My advice is to get an engineer to calculate. That said, if you elect
not to follow that advice and are going to glue it then use a UF or
Resorcinol type structural glue - the sort used in Glulam beams.
Supplement this with decent screws at calculated centres. How about a
compromise and go for coach screws with 2" plate washers, double
sided connectors amd use the conventional edge end and spacing
distances which I would guess on a 7" timber will be 50 mm from the
edge, 75mm from the end and not less than say 150mm spacing between
screws. You could get three sets in staggered lines along a 7 " timber
- one 50 from the top - one 50 from the bottom both in line vertically
and one staggered in the neutral axis.

When you say double sided connectors here - do you mean screw from
both sides? i.e., 3 coach screws from either side?

Alternatively use four bolts in a rectangular pattern 50mm edge 75 mm
end and say 350 mm spacing should see you right

Thanks Chris, I think I'll have another quick look tonight to confirm
setting timber in the web is definately not an option, and plan B will
bolt through.

Niall

Niall Smart wrote:
Hi,

I've removed an interior block wall which was supporting some joists
and installed a steel beam at joist level to support the floors and
the interior wall above. I had to cut the joists 1-2" short of the
beam in order to fit it at the level of the joists. What is the best
way to extend the joists into the web of the beam? I was thinking of
lap jointing short (i.e., 60cm) lengths of timber (7x1.5) which would
be screwed and glued to the existing joists.

Is this method of fixing sufficiently strong, or should I be using
bolts & toothed plate timber connectors? Is there a better way?

A piccie might help...


It sounds like you have:

########
## @@@@@@@@@@@@@@@@@@@@@@@@@@@
## @@@@@@@@@@@@@@@@@@@@@@@@@@
## @@@@@ Timber Joist End @@@@
## @@@@@@@@@@@@@@@@@@@@@@@@@@@@
## @@@@@@@@@@@@@@@@@@@@@@@@@@@@@
########

In which case, extending the beam to meet the joists sounds easier:

########
##~~~~~~@@@@@@@@@@@@@@@@@@@@@@@@@@@
##~~~~~~@@@@@@@@@@@@@@@@@@@@@@@@@@
B##~~~~~~@@@@@ Timber Joist End @@@@
##~~~~~~@@@@@@@@@@@@@@@@@@@@@@@@@@@@
##~~~~~~@@@@@@@@@@@@@@@@@@@@@@@@@@@@@
########

Insert a timber section in the web, running the length of the RSJ, bolt
it at regular intervals through the joist. And then use ordinary joist
hangers nailed to it to carry the cut ends of the joists.




--
Cheers,

John.

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

On Nov 13, 11:31 pm, dg wrote:
On 13 Nov, 22:10, Niall Smart wrote:

Hi,

I've removed an interior block wall which was supporting some joists
and installed a steel beam at joist level to support the floors and
the interior wall above. I had to cut the joists 1-2" short of the
beam in order to fit it at the level of the joists. What is the best
way to extend the joists into the web of the beam? I was thinking of
lap jointing short (i.e., 60cm) lengths of timber (7x1.5) which would
be screwed and glued to the existing joists.

Is this method of fixing sufficiently strong, or should I be using
bolts & toothed plate timber connectors? Is there a better way?

Niall

You don't extend the joists.

Either hang the joists off the top of the beam with hangers, or if
possible fit a timber section into the beam web and fix hangers to
this to hang the joists off

So how do you do that when the joists have been cut 1-2" short.

MBQ

Man at B&Q wrote:
On Nov 13, 11:31 pm, dg wrote:
On 13 Nov, 22:10, Niall Smart wrote:

Hi,
I've removed an interior block wall which was supporting some joists
and installed a steel beam at joist level to support the floors and
the interior wall above. I had to cut the joists 1-2" short of the
beam in order to fit it at the level of the joists. What is the best
way to extend the joists into the web of the beam? I was thinking of
lap jointing short (i.e., 60cm) lengths of timber (7x1.5) which would
be screwed and glued to the existing joists.
Is this method of fixing sufficiently strong, or should I be using
bolts & toothed plate timber connectors? Is there a better way?
Niall
You don't extend the joists.

Either hang the joists off the top of the beam with hangers, or if
possible fit a timber section into the beam web and fix hangers to
this to hang the joists off

So how do you do that when the joists have been cut 1-2" short.

It's hard to get the wood in the flange post erection..If its possible
welding plates inside the lower flange to support the wood on is one
approach, or could use bolts..but the best approach suggested would seem
to be the last posters one - extend the existing beams with a beam
either side, lodged in the flange and bolted through the existing beam
using those spider plate things between the wood parts. If you are
worried about those beams shifting, drill CSK holes in the lower flange
and use woodscrews or nails banged in upwards to locate.

Pack all the beams with ply sheets to get a level surface to re-board
the ceiling to...


MBQ

On Nov 14, 3:49 pm, The Natural Philosopher wrote:
Man at B&Q wrote:
On Nov 13, 11:31 pm, dg wrote:
On 13 Nov, 22:10, Niall Smart wrote:

Hi,
I've removed an interior block wall which was supporting some joists
and installed a steel beam at joist level to support the floors and
the interior wall above. I had to cut the joists 1-2" short of the
beam in order to fit it at the level of the joists. What is the best
way to extend the joists into the web of the beam? I was thinking of
lap jointing short (i.e., 60cm) lengths of timber (7x1.5) which would
be screwed and glued to the existing joists.
Is this method of fixing sufficiently strong, or should I be using
bolts & toothed plate timber connectors? Is there a better way?
Niall
You don't extend the joists.

Either hang the joists off the top of the beam with hangers, or if
possible fit a timber section into the beam web and fix hangers to
this to hang the joists off

So how do you do that when the joists have been cut 1-2" short.

It's hard to get the wood in the flange post erection..If its possible
welding plates inside the lower flange to support the wood on is one
approach, or could use bolts..but the best approach suggested would seem
to be the last posters one - extend the existing beams with a beam
either side, lodged in the flange and bolted through the existing beam
using those spider plate things between the wood parts. If you are
worried about those beams shifting, drill CSK holes in the lower flange
and use woodscrews or nails banged in upwards to locate.

Pack all the beams with ply sheets to get a level surface to re-board
the ceiling to...

Or arrange the joist extensions to be slightly offset vertically so
that the joists are flush with the top of the beam.

MBQ

In article , John Rumm
writes
Niall Smart wrote:
Hi,

I've removed an interior block wall which was supporting some joists
and installed a steel beam at joist level to support the floors and
the interior wall above. I had to cut the joists 1-2" short of the
beam in order to fit it at the level of the joists. What is the best
way to extend the joists into the web of the beam? I was thinking of
lap jointing short (i.e., 60cm) lengths of timber (7x1.5) which would
be screwed and glued to the existing joists.

Is this method of fixing sufficiently strong, or should I be using
bolts & toothed plate timber connectors? Is there a better way?

A piccie might help...


It sounds like you have:

########
## @@@@@@@@@@@@@@@@@@@@@@@@@@@
## @@@@@@@@@@@@@@@@@@@@@@@@@@
## @@@@@ Timber Joist End @@@@
## @@@@@@@@@@@@@@@@@@@@@@@@@@@@
## @@@@@@@@@@@@@@@@@@@@@@@@@@@@@
########

In which case, extending the beam to meet the joists sounds easier:

########
##~~~~~~@@@@@@@@@@@@@@@@@@@@@@@@@@@
##~~~~~~@@@@@@@@@@@@@@@@@@@@@@@@@@
B##~~~~~~@@@@@ Timber Joist End @@@@
##~~~~~~@@@@@@@@@@@@@@@@@@@@@@@@@@@@
##~~~~~~@@@@@@@@@@@@@@@@@@@@@@@@@@@@@
########

Insert a timber section in the web, running the length of the RSJ, bolt
it at regular intervals through the joist. And then use ordinary joist
hangers nailed to it to carry the cut ends of the joists.

That looks like quite a nasty rotational moment on the RSJ, I'd be
worried about just using hangers.
--
fred
Plusnet - I hope you like vanilla

fred wrote:
In article , John Rumm
writes
Niall Smart wrote:
Hi,

I've removed an interior block wall which was supporting some joists
and installed a steel beam at joist level to support the floors and
the interior wall above. I had to cut the joists 1-2" short of the
beam in order to fit it at the level of the joists. What is the best
way to extend the joists into the web of the beam? I was thinking of
lap jointing short (i.e., 60cm) lengths of timber (7x1.5) which would
be screwed and glued to the existing joists.

Is this method of fixing sufficiently strong, or should I be using
bolts & toothed plate timber connectors? Is there a better way?

A piccie might help...


It sounds like you have:

########
## @@@@@@@@@@@@@@@@@@@@@@@@@@@
## @@@@@@@@@@@@@@@@@@@@@@@@@@
## @@@@@ Timber Joist End @@@@
## @@@@@@@@@@@@@@@@@@@@@@@@@@@@
## @@@@@@@@@@@@@@@@@@@@@@@@@@@@@
########

In which case, extending the beam to meet the joists sounds easier:

########
##~~~~~~@@@@@@@@@@@@@@@@@@@@@@@@@@@
##~~~~~~@@@@@@@@@@@@@@@@@@@@@@@@@@
B##~~~~~~@@@@@ Timber Joist End @@@@
##~~~~~~@@@@@@@@@@@@@@@@@@@@@@@@@@@@
##~~~~~~@@@@@@@@@@@@@@@@@@@@@@@@@@@@@
########

Insert a timber section in the web, running the length of the RSJ, bolt
it at regular intervals through the joist. And then use ordinary joist
hangers nailed to it to carry the cut ends of the joists.

That looks like quite a nasty rotational moment on the RSJ, I'd be
worried about just using hangers.

I only drew one side of it - from the description I am assuming you
would do the same on both sides. Note also that the joists are only a
couple of inches short - so you are only talking about 50mm of wood in
the web.



--
Cheers,

John.

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

In article , John Rumm
writes
fred wrote:
In article , John Rumm
writes
Niall Smart wrote:
Hi,

I've removed an interior block wall which was supporting some joists
and installed a steel beam at joist level to support the floors and
the interior wall above. I had to cut the joists 1-2" short of the
beam in order to fit it at the level of the joists. What is the best
way to extend the joists into the web of the beam? I was thinking of
lap jointing short (i.e., 60cm) lengths of timber (7x1.5) which would
be screwed and glued to the existing joists.

Is this method of fixing sufficiently strong, or should I be using
bolts & toothed plate timber connectors? Is there a better way?

A piccie might help...


It sounds like you have:

########
## @@@@@@@@@@@@@@@@@@@@@@@@@@@
## @@@@@@@@@@@@@@@@@@@@@@@@@@
## @@@@@ Timber Joist End @@@@
## @@@@@@@@@@@@@@@@@@@@@@@@@@@@
## @@@@@@@@@@@@@@@@@@@@@@@@@@@@@
########

In which case, extending the beam to meet the joists sounds easier:

########
##~~~~~~@@@@@@@@@@@@@@@@@@@@@@@@@@@
##~~~~~~@@@@@@@@@@@@@@@@@@@@@@@@@@
B##~~~~~~@@@@@ Timber Joist End @@@@
##~~~~~~@@@@@@@@@@@@@@@@@@@@@@@@@@@@
##~~~~~~@@@@@@@@@@@@@@@@@@@@@@@@@@@@@
########

Insert a timber section in the web, running the length of the RSJ, bolt
it at regular intervals through the joist. And then use ordinary joist
hangers nailed to it to carry the cut ends of the joists.

That looks like quite a nasty rotational moment on the RSJ, I'd be
worried about just using hangers.

I only drew one side of it - from the description I am assuming you
would do the same on both sides. Note also that the joists are only a
couple of inches short - so you are only talking about 50mm of wood in
the web.

I was looking at it as being 50mm short of the end of the base flange
and then mistakenly thought that would be a 100mm lever about the centre
of the beam but it I think it is the overhang from the end of the base
plate that is significant.

Fair enough about the balancing effect from the other side but I was
thinking of party loading and did a quick fag packet calculation:

30 partygoers averaging 14st in room 1 = 89kg x 30 = 2670kg
Assuming even distribution gives 1335kg each end.
If the mounting point of the hangers is 50mm from the end of the base
flange then there is a 1335 x 10 x 0.05 = 668Nm rotational moment on the
beam, which is quite a lot.

I'm not saying it is a no hoper but I bet it's not an issue that many
would consider in this situation.

It means nothing of course if the o/p's joist are just butting the base
flange, then it would be just fine.
--
fred
Plusnet - I hope you like vanilla