I've never got the hang of when timber is going to be the size you ask
for and when it will be smaller, due to the method of sizing the
unfinished product. And it seems to vary around the UK. This never
mattered before.
Now, I have on my plans, sizes like 75mm x 225mm joists to fit into
matching joist hangers, and all the fittings should be tight. I will
order the timber from a proper merchants, since some is graded C24
etc, and must not warp.
So if I order 75mm wide joist hangers will the inside measurement be
exactly that ?
Assuming it is, I need timber that is exactly 75mm wide. However, a
lot of timber is regularized and rounded on the corners, and is
probably smaller than the size you ask for.
What should I ask for to a) not look like an arse (no comments ...),
and b) get the finished sizes I need ?
In the Midlands.
Cheers,
Simon.

In article
,
sm_jamieson wrote:
I've never got the hang of when timber is going to be the size you ask
for and when it will be smaller, due to the method of sizing the
unfinished product. And it seems to vary around the UK. This never
mattered before.

Basically sawn wood should be the size quoted. Planed wood starts out as
sawn and varies slightly according to how much is needed to be planed off
to get it smooth.

So constructional timber should be to the dimensions quoted.

--
*Seen it all, done it all, can't remember most of it*

Dave Plowman London SW
To e-mail, change noise into sound.

sm_jamieson wrote:
I've never got the hang of when timber is going to be the size you ask
for and when it will be smaller, due to the method of sizing the
unfinished product. And it seems to vary around the UK. This never
mattered before.

Nope, *standard* timber sizes don't vary that much around the country.

Now, I have on my plans, sizes like 75mm x 225mm joists to fit into
matching joist hangers, and all the fittings should be tight. I will
order the timber from a proper merchants, since some is graded C24
etc, and must not warp.

If you can find any 'natural' timber guaranteed *NOT* to warp, let the group
know - BTW, that's why you use herring bone or solid strutting between the
joists to try and stop them moving too much.

So if I order 75mm wide joist hangers will the inside measurement be
exactly that ?

No necessarily - if the fit of the joist is too loose for your liking,
simply stick a packing piece on side or the other before fixing the said
joist!

BTW, why are you using 75mm (3") thick joists? The standard is usually 50mm
(2") - unless you are trimming around an opening such as a stair well.

Assuming it is, I need timber that is exactly 75mm wide. However, a
lot of timber is regularized and rounded on the corners, and is
probably smaller than the size you ask for.
What should I ask for to a) not look like an arse (no comments ...),
and b) get the finished sizes I need ?
In the Midlands.
Cheers,

If you joists and exact size - then simply ask for 'dimension sawn' timber -
and you will get what you want.

Cash

On 18 July, 13:10, "Cash"
wrote:
sm_jamieson wrote:
I've never got the hang of when timber is going to be the size you ask
for and when it will be smaller, due to the method of sizing the
unfinished product. And it seems to vary around the UK. This never
mattered before.

Nope, *standard* timber sizes don't vary that much around the country.

Now, I have on my plans, sizes like 75mm x 225mm joists to fit into
matching joist hangers, and all the fittings should be tight. I will
order the timber from a proper merchants, since some is graded C24
etc, and must not warp.

If you can find any 'natural' timber guaranteed *NOT* to warp, let the group
know - BTW, that's why you use herring bone or solid strutting between the
joists to try and stop them moving too much.

True I know. But for biggish beams like purlins etc, a bad warp could
be enough to
damage an aircrete wall as it dries, I would have thought.
Most warps happen around knots in the wood in my experience, so C24
rated
timber should warp less, since it has less knots in it.


So if I order 75mm wide joist hangers will the inside measurement be
exactly that ?

No necessarily - if the fit of the joist is too loose for your liking,
simply stick a packing piece on side or the other before fixing the said
joist!

BTW, why are you using 75mm (3") thick joists? *The standard is usually 50mm
(2") - unless you are trimming around an opening such as a stair well.

Assuming it is, I need timber that is exactly 75mm wide. However, a
lot of timber is regularized and rounded on the corners, and is
probably smaller than the size you ask for.
What should I ask for to a) not look like an arse (no comments ...),
and b) get the finished sizes I need ?
In the Midlands.
Cheers,

If you joists and exact size - then simply ask for 'dimension sawn' timber -
and you will get what you want.
Thanks, will do.
Simon.

Most joist hangers nip up quite easily - and yes they will be exactly
75mm internally.

Simon wrote:
On 18 July, 13:10, "Cash"
wrote:
sm_jamieson wrote:
I've never got the hang of when timber is going to be the size you
ask for and when it will be smaller, due to the method of sizing the
unfinished product. And it seems to vary around the UK. This never
mattered before.

Nope, *standard* timber sizes don't vary that much around the
country.

Now, I have on my plans, sizes like 75mm x 225mm joists to fit into
matching joist hangers, and all the fittings should be tight. I will
order the timber from a proper merchants, since some is graded C24
etc, and must not warp.

If you can find any 'natural' timber guaranteed *NOT* to warp, let
the group know - BTW, that's why you use herring bone or solid
strutting between the joists to try and stop them moving too much.

True I know. But for biggish beams like purlins etc, a bad warp could
be enough to
damage an aircrete wall as it dries,

What a load of cobblers - if the joists are that wet, then don't put them in
until they dry out to a moisture content of around 18% - and if they are
*that* wet, tell the timber merchant to stick 'em where the sun never shines
and go and pick your own.

I would have thought.
Most warps happen around knots in the wood in my experience, so C24
rated
timber should warp less, since it has less knots in it.

Another load of cobblers - certainly in my years of experience (many( -
timber will warp, twist, bend and shrink regardless of the amount of knots -
but knots will weaken timber, that's why the number of them will affect the
stress gradings that are used.

So if I order 75mm wide joist hangers will the inside measurement be
exactly that ?

No necessarily - if the fit of the joist is too loose for your
liking, simply stick a packing piece on side or the other before
fixing the said joist!

BTW, why are you using 75mm (3") thick joists? The standard is
usually 50mm (2") - unless you are trimming around an opening such
as a stair well.

Assuming it is, I need timber that is exactly 75mm wide. However, a
lot of timber is regularized and rounded on the corners, and is
probably smaller than the size you ask for.
What should I ask for to a) not look like an arse (no comments ...),
and b) get the finished sizes I need ?
In the Midlands.
Cheers,

If you joists and exact size - then simply ask for 'dimension sawn'
timber - and you will get what you want.
Thanks, will do.
Simon.


Cash

On 18 July, 16:38, "Cash"
wrote:
Simon wrote:
On 18 July, 13:10, "Cash"
wrote:
sm_jamieson wrote:
I've never got the hang of when timber is going to be the size you
ask for and when it will be smaller, due to the method of sizing the
unfinished product. And it seems to vary around the UK. This never
mattered before.

Nope, *standard* timber sizes don't vary that much around the
country.

Now, I have on my plans, sizes like 75mm x 225mm joists to fit into
matching joist hangers, and all the fittings should be tight. I will
order the timber from a proper merchants, since some is graded C24
etc, and must not warp.

If you can find any 'natural' timber guaranteed *NOT* to warp, let
the group know - BTW, that's why you use herring bone or solid
strutting between the joists to try and stop them moving too much.

True I know. But for biggish beams like purlins etc, a bad warp could
be enough to
damage an aircrete wall as it dries,

What a load of cobblers - if the joists are that wet, then don't put them in
until they dry out to a moisture content of around 18% - and if they are
*that* wet, tell the timber merchant to stick 'em where the sun never shines
and go and pick your own.

I would have thought.

Most warps happen around knots in the wood in my experience, so C24
rated
timber should warp less, since it has less knots in it.

Another load of cobblers - certainly in my years of experience (many( -
timber will warp, twist, bend and shrink regardless of the amount of knots -
but knots will weaken timber, *that's why the number of them will affect the
stress gradings that are used.



So if I order 75mm wide joist hangers will the inside measurement be
exactly that ?

No necessarily - if the fit of the joist is too loose for your
liking, simply stick a packing piece on side or the other before
fixing the said joist!

BTW, why are you using 75mm (3") thick joists? The standard is
usually 50mm (2") - unless you are trimming around an opening such
as a stair well.

Assuming it is, I need timber that is exactly 75mm wide. However, a
lot of timber is regularized and rounded on the corners, and is
probably smaller than the size you ask for.
What should I ask for to a) not look like an arse (no comments ...),
and b) get the finished sizes I need ?
In the Midlands.
Cheers,

If you joists and exact size - then simply ask for 'dimension sawn'
timber - and you will get what you want.
Thanks, will do.
Simon.

Cash

Have you seen B&Q timber ? I've got several lengths of 4x2 that are
straight until
they get to a knot near the edge, where-upon they diverge at a strange
angle.
They were straight-ish when I got them, have been sat outside but
sheltered for 6 months.
I built a partition wall out of them and didn't plasterboard for a few
weeks and the
partition was twisted a fair bit and I had to bend the plasterboard.

If your experience with timber is always reasonable stuff from timber
merchants,
well there you have it. But B&Q stuff is bad. I don't use it any
more !

Simon.