Catnic style lintel opening size 1500mm. You cannot have point loads
on them, but I will effectively have a single celcon block (440 wide),
then an engineering brick padstone, then the load (end of a purlin),
so would this spread the load enough? Else I could put a concrete
lintel instead of the eng brick to spread the load a bit more, say
over 2 blocks. Of course this is thermal bridging so a balance must be
struck !
Cheers,
Simon.

On 29 June, 16:32, sm_jamieson wrote:
Catnic style lintel opening size 1500mm. You cannot have point loads
on them, but I will effectively have a single celcon block (440 wide),
then an engineering brick padstone, then the load (end of a purlin),
so would this spread the load enough? Else I could put a concrete
lintel instead of the eng brick to spread the load a bit more, say
over 2 blocks. Of course this is thermal bridging so a balance must be
struck !
Cheers,
Simon.

Well, for future ref, the catnic brochure says:

Do not apply point loads without prior consultation. Where the
loading or a substantial part of it is applied as concentrated
loads, each concentrated load must be supported over a
length of lintel of not less than 200mm. In such cases, the
total loading must not produce bending moments or shear
forces greater than those produced by the uniformly
distributed loads specified in the relevant data tables.

So I would imagine a purlin over a whole 440mm block is generally OK.

Simon.

Simon wrote:
On 29 June, 16:32, sm_jamieson wrote:
Catnic style lintel opening size 1500mm. You cannot have point loads
on them, but I will effectively have a single celcon block (440
wide), then an engineering brick padstone, then the load (end of a
purlin), so would this spread the load enough? Else I could put a
concrete lintel instead of the eng brick to spread the load a bit
more, say over 2 blocks. Of course this is thermal bridging so a
balance must be struck !
Cheers,
Simon.

Well, for future ref, the catnic brochure says:

Do not apply point loads without prior consultation. Where the
loading or a substantial part of it is applied as concentrated
loads, each concentrated load must be supported over a
length of lintel of not less than 200mm. In such cases, the
total loading must not produce bending moments or shear
forces greater than those produced by the uniformly
distributed loads specified in the relevant data tables.

So I would imagine a purlin over a whole 440mm block is generally OK.

Simon.

Yes, except that aircrete blocks could crush under the load, better to use a
pre-stressed concrete padstone

--
Phil L
RSRL Tipster Of The Year 2008

On 30 June, 17:54, "Phil L" wrote:
Simon wrote:
On 29 June, 16:32, sm_jamieson wrote:
Catnic style lintel opening size 1500mm. You cannot have point loads
on them, but I will effectively have a single celcon block (440
wide), then an engineering brick padstone, then the load (end of a
purlin), so would this spread the load enough? Else I could put a
concrete lintel instead of the eng brick to spread the load a bit
more, say over 2 blocks. Of course this is thermal bridging so a
balance must be struck !
Cheers,
Simon.

Well, for future ref, the catnic brochure says:

Do not apply point loads without prior consultation. Where the
loading or a substantial part of it is applied as concentrated
loads, each concentrated load must be supported over a
length of lintel of not less than 200mm. In such cases, the
total loading must not produce bending moments or shear
forces greater than those produced by the uniformly
distributed loads specified in the relevant data tables.

So I would imagine a purlin over a whole 440mm block is generally OK.

Simon.

Yes, except that aircrete blocks could crush under the load, better to use a
pre-stressed concrete padstone


Do you mean a padstone between the aircrete block and the purlin,
or a whole concrete block instead of the aircrete. I don't think the
BCO would like
losing a whole aircrete block for insulation reasons.
I believe a common padstone in this situation is simply an engineering
brick, which is what
I mentioned earlier.
I've no objection to putting in a prestressed concrete lintel over the
whole opening if it was
required, but I suspect this would be over-engineering !
Certainly aircrete is used for loadbearing purposes, and I've at least
seen floor joist hangers
directly on aircrete.
Cheers,
Simon.

Simon wrote:
On 30 June, 17:54, "Phil L" wrote:
Simon wrote:
On 29 June, 16:32, sm_jamieson wrote:
Catnic style lintel opening size 1500mm. You cannot have point
loads on them, but I will effectively have a single celcon block
(440 wide), then an engineering brick padstone, then the load (end
of a purlin), so would this spread the load enough? Else I could
put a concrete lintel instead of the eng brick to spread the load
a bit more, say over 2 blocks. Of course this is thermal bridging
so a balance must be struck !
Cheers,
Simon.

Well, for future ref, the catnic brochure says:

Do not apply point loads without prior consultation. Where the
loading or a substantial part of it is applied as concentrated
loads, each concentrated load must be supported over a
length of lintel of not less than 200mm. In such cases, the
total loading must not produce bending moments or shear
forces greater than those produced by the uniformly
distributed loads specified in the relevant data tables.

So I would imagine a purlin over a whole 440mm block is generally
OK.

Simon.

Yes, except that aircrete blocks could crush under the load, better
to use a pre-stressed concrete padstone


Do you mean a padstone between the aircrete block and the purlin,
or a whole concrete block instead of the aircrete. I don't think the
BCO would like
losing a whole aircrete block for insulation reasons.

A pre-stresed lintel is 75H X 100W by whatever length you want to make it -
it's not going to make one iota of difference WRT insulation.

I believe a common padstone in this situation is simply an engineering
brick, which is what
I mentioned earlier.

a brick is only 200mm long.

I've no objection to putting in a prestressed concrete lintel over the
whole opening if it was
required, but I suspect this would be over-engineering !

PS lintels come in many lengths, I was thinking say about 5 - 600mm, then it
covers more than one aircrete block in length.

Certainly aircrete is used for loadbearing purposes, and I've at least
seen floor joist hangers
directly on aircrete.

Floor joists are many and each one takes a small amount of weight, a
*single* purlin takes the weight of all the joists, which are holding up the
battens and tiles and everything else.


--
Phil L
RSRL Tipster Of The Year 2008

On 30 June, 21:23, "Phil L" wrote:
Simon wrote:
On 30 June, 17:54, "Phil L" wrote:
Simon wrote:
On 29 June, 16:32, sm_jamieson wrote:
Catnic style lintel opening size 1500mm. You cannot have point
loads on them, but I will effectively have a single celcon block
(440 wide), then an engineering brick padstone, then the load (end
of a purlin), so would this spread the load enough? Else I could
put a concrete lintel instead of the eng brick to spread the load
a bit more, say over 2 blocks. Of course this is thermal bridging
so a balance must be struck !
Cheers,
Simon.

Well, for future ref, the catnic brochure says:

Do not apply point loads without prior consultation. Where the
loading or a substantial part of it is applied as concentrated
loads, each concentrated load must be supported over a
length of lintel of not less than 200mm. In such cases, the
total loading must not produce bending moments or shear
forces greater than those produced by the uniformly
distributed loads specified in the relevant data tables.

So I would imagine a purlin over a whole 440mm block is generally
OK.

Simon.

Yes, except that aircrete blocks could crush under the load, better
to use a pre-stressed concrete padstone

Do you mean a padstone between the aircrete block and the purlin,
or a whole concrete block instead of the aircrete. I don't think the
BCO would like
losing a whole aircrete block for insulation reasons.

A pre-stresed lintel is 75H X 100W by whatever length you want to make it -
it's not going to make one iota of difference WRT insulation.

I believe a common padstone in this situation is simply an engineering
brick, which is what
I mentioned earlier.

a brick is only 200mm long.

I've no objection to putting in a prestressed concrete lintel over the
whole opening if it was
required, but I suspect this would be over-engineering !

PS lintels come in many lengths, I was thinking say about 5 - 600mm, then it
covers more than one aircrete block in length.

Certainly aircrete is used for loadbearing purposes, and I've at least
seen floor joist hangers
directly on aircrete.

Floor joists are many and each one takes a small amount of weight, a
*single* purlin takes the weight of all the joists, which are holding up the
battens and tiles and everything else.

--
Thanks, I understand what you're saying now.
Sounds like a good idea.
Simon.