As many will remember, I'm fixing up a bungalow, circa 1955, very bodged
dormer conversion circa 1970s. We're doing the upstairs floor now. The
main floor was strengthened with 8x2" joists run to all 3 wall plates (2
external plus centre wall). However, in some "alcoves" this was not done
- the 4x2" ceiling joists were packed up with more 4x2 (badly). This is
NOT a cause for concern in itself - ceilings are fine, old ceiling
joists are very good quality wood and spans are modest.



Here's the layout in the south east corner (SE corner is top right,
black lines are main walls, other structures annotated):

https://goo.gl/n1fftC


The problem is the tie beam on the right side. These probably ran all
the way through originally - but were cut short when the dormer was
installed. Clearly not a problem as it's been happy for 40 years.

But we found woodwork had eaten the section marked "Woodwormed" in pink
in the diagram above. Looks like that happened a long time ago - no
evidence of current activity and all surrounding timbers completely
untouched.

So we cut out the worse section leaving the green bit which is 100%
sound. There are 3 more such tie beams, the north east one is shown in
the diagram on the left in green.


Given it is probably fixed to the rafter with 1-2 rusty 4" nails,
clearly it cannot be under *that* much tension, but it seems wise to
consider if the missing bit was contributing useful work.




On to the new plan:

https://goo.gl/GYkUBE


In order to strengthen the floor, we've put in a new 4x2 on its side to
the right also in green, screwed through to the ceiling rafters. New
4x2" joists will go on top of the ceiling joists, half lapped onto this
and glued and screwed to the ceiling joists. This will also form the
base plate of a small stud wall.

Obviously not how you'd do it if starting from scratch, but it should be
more solid that the original which stood having a 1/4 ton cold water
tank (gone) plus the usual junk stored there.



The actual thing I am wondering is how much of that tie beam it is worth
putting back. If I add the "Optional noggins" in red as shown, but bolt
them through to each other and onto the end of the tie beam with heavy
brackets and M10 bolts, I could effectively reinstate the beam as it was
last week.

OTOH the new "4x2 on side" is tying the ceiling joists anyway and the
tie beam is fixed to the same joist at the end. Not only that, but all
rafters are tied back to the first ceiling joist as well as the wall
plate to some extent by the vertical yellow 4x2 straps which are forming
a horizontal frame which must be pretty stiff in the sideways direction.


I've never been sure how much work tie beams actually do - and the wall
plate is pretty substantial (4x3" IIRC).


Anyone dare venture an opinion: a) Belt and braces; b) Nah it's OK?


Cheers,

Tim

Tim Watts wrote:
As many will remember, I'm fixing up a bungalow, circa 1955, very
bodged dormer conversion circa 1970s. We're doing the upstairs floor
now. The main floor was strengthened with 8x2" joists run to all 3
wall plates (2 external plus centre wall). However, in some "alcoves"
this was not done - the 4x2" ceiling joists were packed up with more
4x2 (badly). This is NOT a cause for concern in itself - ceilings are
fine, old ceiling joists are very good quality wood and spans are modest.



Here's the layout in the south east corner (SE corner is top right,
black lines are main walls, other structures annotated):

https://goo.gl/n1fftC


The problem is the tie beam on the right side. These probably ran all
the way through originally - but were cut short when the dormer was
installed. Clearly not a problem as it's been happy for 40 years.

But we found woodwork had eaten the section marked "Woodwormed" in
pink in the diagram above. Looks like that happened a long time ago -
no evidence of current activity and all surrounding timbers completely
untouched.

So we cut out the worse section leaving the green bit which is 100%
sound. There are 3 more such tie beams, the north east one is shown in
the diagram on the left in green.


Given it is probably fixed to the rafter with 1-2 rusty 4" nails,
clearly it cannot be under *that* much tension, but it seems wise to
consider if the missing bit was contributing useful work.




On to the new plan:

https://goo.gl/GYkUBE


In order to strengthen the floor, we've put in a new 4x2 on its side
to the right also in green, screwed through to the ceiling rafters.
New 4x2" joists will go on top of the ceiling joists, half lapped onto
this and glued and screwed to the ceiling joists. This will also form
the base plate of a small stud wall.

Obviously not how you'd do it if starting from scratch, but it should
be more solid that the original which stood having a 1/4 ton cold
water tank (gone) plus the usual junk stored there.



The actual thing I am wondering is how much of that tie beam it is
worth putting back. If I add the "Optional noggins" in red as shown,
but bolt them through to each other and onto the end of the tie beam
with heavy brackets and M10 bolts, I could effectively reinstate the
beam as it was last week.

OTOH the new "4x2 on side" is tying the ceiling joists anyway and the
tie beam is fixed to the same joist at the end. Not only that, but all
rafters are tied back to the first ceiling joist as well as the wall
plate to some extent by the vertical yellow 4x2 straps which are
forming a horizontal frame which must be pretty stiff in the sideways
direction.


I've never been sure how much work tie beams actually do - and the
wall plate is pretty substantial (4x3" IIRC).


Anyone dare venture an opinion: a) Belt and braces; b) Nah it's OK?


Cheers,

Tim
I wonder what it would be like to have a viewable picture?

On 07/02/16 13:54, Capitol wrote:
https://goo.gl/n1fftC

https://goo.gl/GYkUBE

I wonder what it would be like to have a viewable picture?

Are they not working for you? I did check in Chrome Incognito and they
seem to be publicly viewable...

Tim Watts wrote:
On 07/02/16 13:54, Capitol wrote:
https://goo.gl/n1fftC

https://goo.gl/GYkUBE

I wonder what it would be like to have a viewable picture?

Are they not working for you? I did check in Chrome Incognito and they
seem to be publicly viewable...
He might mean actual picture of the beams.

On 08/02/16 10:22, F Murtz wrote:
Tim Watts wrote:
On 07/02/16 13:54, Capitol wrote:
https://goo.gl/n1fftC

https://goo.gl/GYkUBE

I wonder what it would be like to have a viewable picture?

Are they not working for you? I did check in Chrome Incognito and they
seem to be publicly viewable...
He might mean actual picture of the beams.


Happy to upload if Capitol confirms (because I'll have to spend some
time digging for the ones I took a few weeks ago).

I'm actually going to run this lot through Superbeam to see what I
reckon that section of floor is good for.

I am excess of 100kg and I can stand on a single ceiling joist mid span
without excessive deflection (well the ceiling did not crack!) - and I
have done may times.

So the crudest estimation is, if all ceiling joists are tied together
with noggins at both ends of the floor area, it will probably be good
for 800+kg - that's more than you could get lardbutts like me in that
space due to the rapidly diminishing ceiling height, the highest bit of
the ceiling being over the centre load bearing wall too.

Cannot think why the original willoughby didn't just run a full set of
8x2's right through. Actually if it were me and engineering calcs
permitting, I might have just been inclined to run an RSJ or flitch beam
perpendicular *underneath* the joists mid span into the rooms below -
got extra head height to boot.

On 07/02/2016 12:45, Tim Watts wrote:

I've never been sure how much work tie beams actually do - and the wall
plate is pretty substantial (4x3" IIRC).


Anyone dare venture an opinion: a) Belt and braces; b) Nah it's OK?

TBH the tie beams don't do that much... they mainly give lateral bracing
that makes it harder for the joints to twist or buckle. They can't give
much vertical support since as you say they are only held by nails
acting in tension.

You could replace them with noggings or, better still, herringbone
(traditional wood or modern metal)


--
Cheers,

John.

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

On 07/02/16 14:58, John Rumm wrote:
On 07/02/2016 12:45, Tim Watts wrote:

I've never been sure how much work tie beams actually do - and the wall
plate is pretty substantial (4x3" IIRC).


Anyone dare venture an opinion: a) Belt and braces; b) Nah it's OK?

TBH the tie beams don't do that much... they mainly give lateral bracing
that makes it harder for the joints to twist or buckle. They can't give
much vertical support since as you say they are only held by nails
acting in tension.

You could replace them with noggings or, better still, herringbone
(traditional wood or modern metal)

Thanks John,

We'll be adding lots of noggins (and have done where it does not impede
plumbing)

Possibly a slight misunderstanding - I was wondering how much *tension*
tie beams were under in a simple hipped roof?

I know that due to the triangle construction, there is some tendency for
the roof to spread outwards and the tie beams countered this.

What I am not sure of is how much restraint is required. I've heard of
some traditional roofs that don't have ties, whereas all the ones I've
seen (not many) usually have 2 at the 1/4 and 3/4 position (presumably
the centre wall plate provides a tie at the 1/2 way point).


Cheers,

Tim

On 07/02/2016 15:41, Tim Watts wrote:
On 07/02/16 14:58, John Rumm wrote:
On 07/02/2016 12:45, Tim Watts wrote:

I've never been sure how much work tie beams actually do - and the wall
plate is pretty substantial (4x3" IIRC).


Anyone dare venture an opinion: a) Belt and braces; b) Nah it's OK?

TBH the tie beams don't do that much... they mainly give lateral bracing
that makes it harder for the joints to twist or buckle. They can't give
much vertical support since as you say they are only held by nails
acting in tension.

You could replace them with noggings or, better still, herringbone
(traditional wood or modern metal)

Thanks John,

We'll be adding lots of noggins (and have done where it does not impede
plumbing)

That's where herringbone can help - leaves more gaps!

Possibly a slight misunderstanding - I was wondering how much *tension*
tie beams were under in a simple hipped roof?

Ah, yup see what you mean...

Again I think the answer is possibly less than you might expect, since
many hipped roof places are also semi detached, and hence the ties do
not pass through the party wall - they in effect don't actually tie one
side of the structure to the other. In yours they could, but again you
are talking about a couple of nails in shear on the end of a timber
where it itself is also weak in shear.

I know that due to the triangle construction, there is some tendency for
the roof to spread outwards and the tie beams countered this.

The wall plate ought to be well nailed down (and these days strapped as
well) to stop that moving (hence transferring some of the thrust to a
bending moment on the wall plate, and lateral push on the walls. The
heavy bracing work is normally done by the purlins and any A frame style
ties between the rafters (which in your case are probably holding up the
upstairs ceilings!)

What I am not sure of is how much restraint is required. I've heard of
some traditional roofs that don't have ties, whereas all the ones I've
seen (not many) usually have 2 at the 1/4 and 3/4 position (presumably
the centre wall plate provides a tie at the 1/2 way point).

They are normally placed mid span of the ceiling joists (or sometimes
1/3 and 2/3 if there are a pair front and back (i.e. 4 total) on larger
roomed properties.


--
Cheers,

John.

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

On 07/02/16 16:47, John Rumm wrote:
On 07/02/2016 15:41, Tim Watts wrote:
On 07/02/16 14:58, John Rumm wrote:
On 07/02/2016 12:45, Tim Watts wrote:

I've never been sure how much work tie beams actually do - and the wall
plate is pretty substantial (4x3" IIRC).


Anyone dare venture an opinion: a) Belt and braces; b) Nah it's OK?

TBH the tie beams don't do that much... they mainly give lateral bracing
that makes it harder for the joints to twist or buckle. They can't give
much vertical support since as you say they are only held by nails
acting in tension.

You could replace them with noggings or, better still, herringbone
(traditional wood or modern metal)

Thanks John,

We'll be adding lots of noggins (and have done where it does not impede
plumbing)

That's where herringbone can help - leaves more gaps!

Possibly a slight misunderstanding - I was wondering how much *tension*
tie beams were under in a simple hipped roof?

Ah, yup see what you mean...

Again I think the answer is possibly less than you might expect, since
many hipped roof places are also semi detached, and hence the ties do
not pass through the party wall - they in effect don't actually tie one
side of the structure to the other. In yours they could, but again you
are talking about a couple of nails in shear on the end of a timber
where it itself is also weak in shear.

I know that due to the triangle construction, there is some tendency for
the roof to spread outwards and the tie beams countered this.

The wall plate ought to be well nailed down (and these days strapped as
well) to stop that moving (hence transferring some of the thrust to a
bending moment on the wall plate, and lateral push on the walls. The
heavy bracing work is normally done by the purlins and any A frame style
ties between the rafters (which in your case are probably holding up the
upstairs ceilings!)

That's reassuring - thanks John.

We are improving the purlin supports too (cut free end, the other is
well nailed to the hip beam).

It is quite nice taking out a certain amount of the shonky crap from the
70s and putting back something that is a) straight; b) might actually do
something useful!

What I am not sure of is how much restraint is required. I've heard of
some traditional roofs that don't have ties, whereas all the ones I've
seen (not many) usually have 2 at the 1/4 and 3/4 position (presumably
the centre wall plate provides a tie at the 1/2 way point).

They are normally placed mid span of the ceiling joists (or sometimes
1/3 and 2/3 if there are a pair front and back (i.e. 4 total) on larger
roomed properties.



Cheers

Tim

On 2/7/2016 4:47 PM, John Rumm wrote:
On 07/02/2016 15:41, Tim Watts wrote:
On 07/02/16 14:58, John Rumm wrote:
On 07/02/2016 12:45, Tim Watts wrote:

I've never been sure how much work tie beams actually do - and the wall
plate is pretty substantial (4x3" IIRC).


Anyone dare venture an opinion: a) Belt and braces; b) Nah it's OK?

TBH the tie beams don't do that much... they mainly give lateral bracing
that makes it harder for the joints to twist or buckle. They can't give
much vertical support since as you say they are only held by nails
acting in tension.

You could replace them with noggings or, better still, herringbone
(traditional wood or modern metal)

Thanks John,

We'll be adding lots of noggins (and have done where it does not impede
plumbing)

That's where herringbone can help - leaves more gaps!

Possibly a slight misunderstanding - I was wondering how much *tension*
tie beams were under in a simple hipped roof?

Ah, yup see what you mean...

Again I think the answer is possibly less than you might expect, since
many hipped roof places are also semi detached, and hence the ties do
not pass through the party wall - they in effect don't actually tie one
side of the structure to the other. In yours they could, but again you
are talking about a couple of nails in shear on the end of a timber
where it itself is also weak in shear.

Be careful, the strength of the joint is *not* that of a couple of nails
in shear, it is the friction of two large areas of wood held together by
the *tension* in the nails. And when these get rusty, they lock in the
original tension very well.

On 07/02/16 20:50, newshound wrote:
On 2/7/2016 4:47 PM, John Rumm wrote:
On 07/02/2016 15:41, Tim Watts wrote:
On 07/02/16 14:58, John Rumm wrote:
On 07/02/2016 12:45, Tim Watts wrote:

I've never been sure how much work tie beams actually do - and the
wall
plate is pretty substantial (4x3" IIRC).


Anyone dare venture an opinion: a) Belt and braces; b) Nah it's OK?

TBH the tie beams don't do that much... they mainly give lateral
bracing
that makes it harder for the joints to twist or buckle. They can't give
much vertical support since as you say they are only held by nails
acting in tension.

You could replace them with noggings or, better still, herringbone
(traditional wood or modern metal)

Thanks John,

We'll be adding lots of noggins (and have done where it does not impede
plumbing)

That's where herringbone can help - leaves more gaps!

Possibly a slight misunderstanding - I was wondering how much *tension*
tie beams were under in a simple hipped roof?

Ah, yup see what you mean...

Again I think the answer is possibly less than you might expect, since
many hipped roof places are also semi detached, and hence the ties do
not pass through the party wall - they in effect don't actually tie one
side of the structure to the other. In yours they could, but again you
are talking about a couple of nails in shear on the end of a timber
where it itself is also weak in shear.

Be careful, the strength of the joint is *not* that of a couple of nails
in shear, it is the friction of two large areas of wood held together by
the *tension* in the nails. And when these get rusty, they lock in the
original tension very well.

Well - I reckon there's probably not much to lose by sticking the red
noggins in (2nd drawing) but bolting them together so they are strong in
tension and continue the tie beam. At least I'll get back to how it's
been for 40 years (well bit better as the woodworm bit was like a sponge
for about 3-4 ft).

Having said that, I was wrong when I said "3 other tie beams" - I did
have a look over the NW corner where the stairs are - bugger all tie
beam there (because the stairwell chopped it out) and that's been like
it for years and the roof's not done anything weird.

On Sunday, 7 February 2016 12:46:15 UTC, Tim Watts wrote:
As many will remember, I'm fixing up a bungalow, circa 1955, very bodged
dormer conversion circa 1970s. We're doing the upstairs floor now. The
main floor was strengthened with 8x2" joists run to all 3 wall plates (2
external plus centre wall). However, in some "alcoves" this was not done
- the 4x2" ceiling joists were packed up with more 4x2 (badly). This is
NOT a cause for concern in itself - ceilings are fine, old ceiling
joists are very good quality wood and spans are modest.



Here's the layout in the south east corner (SE corner is top right,
black lines are main walls, other structures annotated):

https://goo.gl/n1fftC


The problem is the tie beam on the right side. These probably ran all
the way through originally - but were cut short when the dormer was
installed. Clearly not a problem as it's been happy for 40 years.

But we found woodwork had eaten the section marked "Woodwormed" in pink
in the diagram above. Looks like that happened a long time ago - no
evidence of current activity and all surrounding timbers completely
untouched.

So we cut out the worse section leaving the green bit which is 100%
sound. There are 3 more such tie beams, the north east one is shown in
the diagram on the left in green.


Given it is probably fixed to the rafter with 1-2 rusty 4" nails,
clearly it cannot be under *that* much tension, but it seems wise to
consider if the missing bit was contributing useful work.




On to the new plan:

https://goo.gl/GYkUBE


In order to strengthen the floor, we've put in a new 4x2 on its side to
the right also in green, screwed through to the ceiling rafters. New
4x2" joists will go on top of the ceiling joists, half lapped onto this
and glued and screwed to the ceiling joists. This will also form the
base plate of a small stud wall.

Obviously not how you'd do it if starting from scratch, but it should be
more solid that the original which stood having a 1/4 ton cold water
tank (gone) plus the usual junk stored there.



The actual thing I am wondering is how much of that tie beam it is worth
putting back. If I add the "Optional noggins" in red as shown, but bolt
them through to each other and onto the end of the tie beam with heavy
brackets and M10 bolts, I could effectively reinstate the beam as it was
last week.

OTOH the new "4x2 on side" is tying the ceiling joists anyway and the
tie beam is fixed to the same joist at the end. Not only that, but all
rafters are tied back to the first ceiling joist as well as the wall
plate to some extent by the vertical yellow 4x2 straps which are forming
a horizontal frame which must be pretty stiff in the sideways direction.


I've never been sure how much work tie beams actually do - and the wall
plate is pretty substantial (4x3" IIRC).


Anyone dare venture an opinion: a) Belt and braces; b) Nah it's OK?


Cheers,

Tim

Tie beams are in tension.
Their purpose is to resist the "spreading" effect generated by the weight of the roof.

The brick outer walls must never be subjected to lateral forces, only vertical ones.

So the tie beams are essential and they must run from the rafter/ wall plate junction at one side of the building to the corresponding junction on the other.
Especially important with tiled roof which can weigh tons.


If you're going to bolt timbers together, use a timber connector trapped between the timbers.
http://www.amazon.co.uk/s/?ie=UTF8&k...sl_uj2nzd9vc_e

This makes a much stronger job.
You will need the big square washers under bolt heads and nuts to force the spikes into the timber.

https://en.wikipedia.org/wiki/Tie_(e...d_Tie-beams.29

On 07/02/2016 15:17, harry wrote:

Tie beams are in tension. Their purpose is to resist the "spreading"
effect generated by the weight of the roof.

The brick outer walls must never be subjected to lateral forces, only
vertical ones.

So the tie beams are essential and they must run from the rafter/
wall plate junction at one side of the building to the corresponding
junction on the other. Especially important with tiled roof which can
weigh tons.

While this is all true, I would suggest its also not what Tim is
discussing here...

With a hipped roof, you normally have the ridge beam parallel to the
spine wall, and that will usually (but not always) run along the centre
of the longer axis of the building. The floor/ceiling joists themselves
run perpendicular to the ridge, and form a strong tie right from one
side of the building to the other by tying the base of every rafter pair
together. This creates two opposing pitched roof faces that are acting
as a self supporting structure, with all thrust directed straight down.

The addition of hipped roof sections onto the side of this structure
typically imposes additional mainly downward loading onto the ridge, the
hip rafters, and the wall.

I believe Tim is describing the individual small timber that is run
across the top of the main axis floor/ceiling joists. Its main purpose
in life is giving lateral restraint to the ceiling joists. A pair of
4x2" (if that) alone are not going to provide any significant lateral
support to the whole roof structure, especially since they are only
nailed to the wall plate and, if you are lucky, one rafter.



--
Cheers,

John.

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

On Sunday, 7 February 2016 18:31:39 UTC, John Rumm wrote:
On 07/02/2016 15:17, harry wrote:

Tie beams are in tension. Their purpose is to resist the "spreading"
effect generated by the weight of the roof.

The brick outer walls must never be subjected to lateral forces, only
vertical ones.

So the tie beams are essential and they must run from the rafter/
wall plate junction at one side of the building to the corresponding
junction on the other. Especially important with tiled roof which can
weigh tons.

While this is all true, I would suggest its also not what Tim is
discussing here...

With a hipped roof, you normally have the ridge beam parallel to the
spine wall, and that will usually (but not always) run along the centre
of the longer axis of the building. The floor/ceiling joists themselves
run perpendicular to the ridge, and form a strong tie right from one
side of the building to the other by tying the base of every rafter pair
together. This creates two opposing pitched roof faces that are acting
as a self supporting structure, with all thrust directed straight down.

The addition of hipped roof sections onto the side of this structure
typically imposes additional mainly downward loading onto the ridge, the
hip rafters, and the wall.

I believe Tim is describing the individual small timber that is run
across the top of the main axis floor/ceiling joists. Its main purpose
in life is giving lateral restraint to the ceiling joists. A pair of
4x2" (if that) alone are not going to provide any significant lateral
support to the whole roof structure, especially since they are only
nailed to the wall plate and, if you are lucky, one rafter.



--
Cheers,

John.

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

No mention of hipped roof.
Methods of construction vary with hipped roof.

On 08/02/2016 07:42, harry wrote:
On Sunday, 7 February 2016 18:31:39 UTC, John Rumm wrote:
On 07/02/2016 15:17, harry wrote:

Tie beams are in tension. Their purpose is to resist the "spreading"
effect generated by the weight of the roof.

The brick outer walls must never be subjected to lateral forces, only
vertical ones.

So the tie beams are essential and they must run from the rafter/
wall plate junction at one side of the building to the corresponding
junction on the other. Especially important with tiled roof which can
weigh tons.

While this is all true, I would suggest its also not what Tim is
discussing here...

With a hipped roof, you normally have the ridge beam parallel to the
spine wall, and that will usually (but not always) run along the centre
of the longer axis of the building. The floor/ceiling joists themselves
run perpendicular to the ridge, and form a strong tie right from one
side of the building to the other by tying the base of every rafter pair
together. This creates two opposing pitched roof faces that are acting
as a self supporting structure, with all thrust directed straight down.

The addition of hipped roof sections onto the side of this structure
typically imposes additional mainly downward loading onto the ridge, the
hip rafters, and the wall.

I believe Tim is describing the individual small timber that is run
across the top of the main axis floor/ceiling joists. Its main purpose
in life is giving lateral restraint to the ceiling joists. A pair of
4x2" (if that) alone are not going to provide any significant lateral
support to the whole roof structure, especially since they are only
nailed to the wall plate and, if you are lucky, one rafter.


No mention of hipped roof.

Well, Tim's diagram shows rafters on both sides of a corner.

(and if were a gable roof, then the situation would be even better since
the tie beam in question is running perpendicular to the ceiling joints)

Methods of construction vary with hipped roof.

Indeed. Just as well I have walked round Tim's place and looked at it in
person ;-)


--
Cheers,

John.

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