Extending a joist
 

Here's another one for the assembled experts ...
I've got one joist that's been cut short and then attached to a trimmer
in order to get round a soil stack - but I want to remove the trimmer as
part of some building work. I plan to screw & glue the extension timber
to the side of the existing joist, are there any rules on how much
overlap, etc?
The joists are about 195x48, it's the joist nearest the wall, it'll be
about 40mm too short when the trimmer is removed.
--
Dave S
(The return email address is a dummy)

In an earlier contribution to this discussion,
Dave wrote:

Here's another one for the assembled experts ...
I've got one joist that's been cut short and then attached to a
trimmer in order to get round a soil stack - but I want to remove the
trimmer as part of some building work. I plan to screw & glue the
extension timber to the side of the existing joist, are there any
rules on how much overlap, etc?
The joists are about 195x48, it's the joist nearest the wall, it'll be
about 40mm too short when the trimmer is removed.


Is it worth it for 40mm? Can't you leave the trimmer in place?
--
Cheers,
Set Square
______
Please reply to newsgroup. Reply address is invalid.

Set Square wrote:
In an earlier contribution to this discussion,
Dave wrote:


Here's another one for the assembled experts ...
I've got one joist that's been cut short and then attached to a
trimmer in order to get round a soil stack - but I want to remove the
trimmer as part of some building work. I plan to screw & glue the
extension timber to the side of the existing joist, are there any
rules on how much overlap, etc?
The joists are about 195x48, it's the joist nearest the wall, it'll be
about 40mm too short when the trimmer is removed.



Is it worth it for 40mm? Can't you leave the trimmer in place?

Unfortunately not. I want to drop the loo soil pipe (and the shower
waste) down between the joists - the trimmer will have to go!

--
Dave S
(The return email address is a dummy)

Dave wrote:
Here's another one for the assembled experts ...
I've got one joist that's been cut short and then attached to a trimmer
in order to get round a soil stack - but I want to remove the trimmer as
part of some building work. I plan to screw & glue the extension timber
to the side of the existing joist, are there any rules on how much
overlap, etc?
The joists are about 195x48, it's the joist nearest the wall, it'll be
about 40mm too short when the trimmer is removed.

.... that should be 400mm!
--
Dave S
(The return email address is a dummy)

"Dave" wrote in message
...
Dave wrote:
Here's another one for the assembled experts ...
I've got one joist that's been cut short and then attached to a
trimmer in order to get round a soil stack - but I want to remove the
trimmer as part of some building work. I plan to screw & glue the
extension timber to the side of the existing joist, are there any
rules on how much overlap, etc?
The joists are about 195x48, it's the joist nearest the wall, it'll
be about 40mm too short when the trimmer is removed.

... that should be 400mm!

overlap should be minimum 26", use 2 suitably long coach bolts with
washers (I use the square type) and put star washers (not sure of the
technical term but the builders merchant knew what I was on about)
between the 2 joists, one bolt 4" in from either end

this order...
bolt, washer, joist, star washer, joist, washer, nut

LJ

in2minds wrote:
"Dave" wrote in message
...

Dave wrote:

Here's another one for the assembled experts ...
I've got one joist that's been cut short and then attached to a
trimmer in order to get round a soil stack - but I want to remove the
trimmer as part of some building work. I plan to screw & glue the
extension timber to the side of the existing joist, are there any
rules on how much overlap, etc?
The joists are about 195x48, it's the joist nearest the wall, it'll
be about 40mm too short when the trimmer is removed.

... that should be 400mm!


overlap should be minimum 26", use 2 suitably long coach bolts with
washers (I use the square type) and put star washers (not sure of the
technical term but the builders merchant knew what I was on about)
between the 2 joists, one bolt 4" in from either end

this order...
bolt, washer, joist, star washer, joist, washer, nut

LJ


Thanks, where did you find the info? I couldn't find anything in the
BRegs or www.

--
Dave S
(The return email address is a dummy)

"in2minds" wrote in message
...

"Dave" wrote in message
...
Dave wrote:
Here's another one for the assembled experts ...
I've got one joist that's been cut short and then attached to a
trimmer in order to get round a soil stack - but I want to remove the
trimmer as part of some building work. I plan to screw & glue the
extension timber to the side of the existing joist, are there any
rules on how much overlap, etc?
The joists are about 195x48, it's the joist nearest the wall, it'll
be about 40mm too short when the trimmer is removed.

... that should be 400mm!

overlap should be minimum 26", use 2 suitably long coach bolts with
washers (I use the square type) and put star washers (not sure of the
technical term but the builders merchant knew what I was on about)
between the 2 joists, one bolt 4" in from either end

this order...
bolt, washer, joist, star washer, joist, washer, nut

LJ


I think those "star washers" are called timber connectors, like this:

http://www.strongtie.co.uk/catalogue...p?fam=4&cat=56

(that was the first site I could find with a picture).

When our loft conversion was done they were supposed to fit those in the
several places where multiple joints were bolted next to each other. They
didn't bother and by the time I noticed and complained it was too late to
take everyting out (or maybe they just lied and said they'd fitted them - I
can't exactly/would rather not remember). And they didn't do the nuts up
more than finger-tight either. And being coach bolts with only a certian
amount of thread they had to fit big piles of washers under the head and nut
so that they didn't run out of thread when "tightening" them - think they
only had one length of coach bolts and couldn't be bothered to get
correct-length ones.

Anyway it hasn't all fallen down yet. Hopefully if you do the job better
than that then yours will be fine.

Regards,
Simon.

When our loft conversion was done they were supposed to fit those in the
several places where multiple joints were bolted next to each other. They
didn't bother and by the time I noticed and complained it was too late to
take everyting out (or maybe they just lied and said they'd fitted them -
I
can't exactly/would rather not remember). And they didn't do the nuts up
more than finger-tight either. And being coach bolts with only a certian
amount of thread they had to fit big piles of washers under the head and
nut
so that they didn't run out of thread when "tightening" them - think they
only had one length of coach bolts and couldn't be bothered to get
correct-length ones.

Anyway it hasn't all fallen down yet. Hopefully if you do the job better
than that then yours will be fine.

Regards,
Simon.

I did some a few months ago and planned to use the
star-washers-or-whatever-they're-called. But they kept the joists apart
however much I tightened the coach bolts. I thought the joints were more
solid without them so didn't use them in the end.

On Mon, 13 Dec 2004 15:05:26 -0000, "in2minds" wrote:


"Dave" wrote in message
...
Dave wrote:
Here's another one for the assembled experts ...
I've got one joist that's been cut short and then attached to a
trimmer in order to get round a soil stack - but I want to remove the
trimmer as part of some building work. I plan to screw & glue the
extension timber to the side of the existing joist, are there any
rules on how much overlap, etc?
The joists are about 195x48, it's the joist nearest the wall, it'll
be about 40mm too short when the trimmer is removed.

... that should be 400mm!

overlap should be minimum 26", use 2 suitably long coach bolts with
washers (I use the square type) and put star washers (not sure of the
technical term but the builders merchant knew what I was on about)
between the 2 joists, one bolt 4" in from either end

this order...
bolt, washer, joist, star washer, joist, washer, nut

That's exactly how our builders have just done it when they had to
re-organise joists to create the hole for a new staircase (and to fill
the hole where the staircase used to be, for that matter).

I think they used hefty (M10 I'd guess) studding rather than coach
bolts.
--
On-line canal route planner: http://www.canalplan.org.uk

(Waterways World site of the month, April 2001)

"rrh" wrote in message
.uk...
When our loft conversion was done they were supposed to fit those in the
several places where multiple joints were bolted next to each other.
They
didn't bother and by the time I noticed and complained it was too late
to
take everyting out (or maybe they just lied and said they'd fitted
them -
I
can't exactly/would rather not remember). And they didn't do the nuts up
more than finger-tight either. And being coach bolts with only a certian
amount of thread they had to fit big piles of washers under the head and
nut
so that they didn't run out of thread when "tightening" them - think
they
only had one length of coach bolts and couldn't be bothered to get
correct-length ones.

Anyway it hasn't all fallen down yet. Hopefully if you do the job better
than that then yours will be fine.

Regards,
Simon.

I did some a few months ago and planned to use the
star-washers-or-whatever-they're-called. But they kept the joists apart
however much I tightened the coach bolts. I thought the joints were more
solid without them so didn't use them in the end.

I assumed the gap was why you did use the star washers so that the joists
can expand and contract symmetrically.

The message k
from "rrh" contains these words:

I did some a few months ago and planned to use the
star-washers-or-whatever-they're-called. But they kept the joists apart
however much I tightened the coach bolts. I thought the joints were more
solid without them so didn't use them in the end.


I did a loft conversion a few years ago and the BCO suggested I use them
on the doubled up joists below the transverse stud walls (that he
insisted on) but he didn't object when I didn't bother.

--
Roger

Nick Atty wrote:


I think they used hefty (M10 I'd guess) studding rather than coach
bolts.

12mm is the standard size for these and plate washers...


--
Cheers,

John.

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\================================================= ================/

Thanks, where did you find the info? I couldn't find anything in the
BRegs or www.


from the BCO (building control officer)... he knows everything (well
thinks he does (c; )

LJ

I did some a few months ago and planned to use the
star-washers-or-whatever-they're-called. But they kept the joists apart
however much I tightened the coach bolts. I thought the joints were more
solid without them so didn't use them in the end.

I assumed the gap was why you did use the star washers so that the joists
can expand and contract symmetrically.

No I don't think so; I believe that ideally the star washers are supposed to
bite deeply into the timber on both sides, leaving little or no gap. The
joists wouldn't need to expand much side to side anyway. My joists might
well have been strong enough if I'd used the washers, but I was happier with
the timbers tight up against one another. Maybe I have unusually hard timber
for my joists...