From around the beginning of February, Mrs P and I will be moving into a
bungalow that is in need of lot of work. I do not yet know how old it is
but I am guessing from between mid-60s to early 70s.

The loft has glass-fibre insulation and is only partialy boarded. I
intend extend the boarding. I boarded my current one with bits of
chipboard let over from work done years ago. Well that was 5/8" board.

Now (soon) I shall need to buy new. It looks as though 18 x 600 x 2400 is
the default today.

The thing is I always aligned board edges along the centre of the joists.
So that would require joists at 600mm.

My house wasn't completed until May 1972 and its joists are at
16" (406mm) centres. The "new" bungalow may be the same age. Should I be
concerned if I intend to lay them at right angles to the joists?

TIA

--
Mint 20.0, kernel 5.4.0-45-generic, Cinnamon 4.6.7
running on an AMD Phenom II X4 Black edition processor with 8GB of DRAM.

In message , pinnerite
writes
From around the beginning of February, Mrs P and I will be moving into a
bungalow that is in need of lot of work. I do not yet know how old it is
but I am guessing from between mid-60s to early 70s.

The loft has glass-fibre insulation and is only partialy boarded. I
intend extend the boarding. I boarded my current one with bits of
chipboard let over from work done years ago. Well that was 5/8" board.

Now (soon) I shall need to buy new. It looks as though 18 x 600 x 2400 is
the default today.

The thing is I always aligned board edges along the centre of the joists.
So that would require joists at 600mm.

My house wasn't completed until May 1972 and its joists are at
16" (406mm) centres. The "new" bungalow may be the same age. Should I be
concerned if I intend to lay them at right angles to the joists?

No. I use polyurethane glue to bond the joints but you might need to
consider access for moving/re-wiring light fittings etc.

Might be good to top up the insulation while you are there. I prefer
Rockwool. Much less irritating for a similar performance.

The electricians will be along shortly worrying about power cables
buried in insulation:-)

--
Tim Lamb

On 31/10/2020 19:57, Tim Lamb wrote:
In message , pinnerite
writes
From around the beginning of February, Mrs P and I will be moving into a
bungalow that is in need of lot of work. I do not yet know how old it is
but I am guessing from between mid-60s to early 70s.

The loft has glass-fibre insulation and is only partialy boarded. I
intend extend the boarding. I boarded my current one with bits of
chipboard let over from work done years ago. Well that was 5/8" board.

Now (soon) I shall need to buy new. It looks as though 18 x 600 x 2400 is
the default today.

The thing is I always aligned board edges along the centre of the joists.
So that would require joists at 600mm.

My house wasn't completed until May 1972 and its joists are at
16" (406mm) centres. The "new" bungalow may be the same age.Â* Should I be
concerned if I intend to lay them at right angles to the joists?

No. I use polyurethane glue to bond the joints but you might need to
consider access for moving/re-wiring light fittings etc.

Might be good to top up the insulation while you are there. I prefer
Rockwool. Much less irritating for a similar performance.

Above the new 'flooring', or squeezed into the 4inch gap under the
flooring ? :-).

Wickes sell special extension supports that lift the boarding up so
that the requisite 300mm of insulation is possible. I made my own
from inch thick plywood, cut into 300 mm long by 100 wide strips,
glued and bolted vertically to the horozontal bars of the trusses
and with 50x50 slot cut into the top end allowing a 3.6 metre length
of 47x47 timber to be carried from side to side, spaced 600 mm apart
and fitted the loft boards to those new rails.

The electricians will be along shortly worrying about power cables
buried in insulation:-)

pinnerite wrote:
Now (soon) I shall need to buy new. It looks as though 18 x 600 x 2400 is
the default today.

You can get 'loft' boards, which are handy if access is tight, but doesn't
address your immediate problem:
https://www.wickes.co.uk/Wickes-Chip...-of-3/p/116420

The thing is I always aligned board edges along the centre of the joists.
So that would require joists at 600mm.

I think traditionally you lay the boards at right angles to the joists, so
your 2400mm covers 6x 400mm-spaced joists. The joins are therefore at
joists where they can be screwed down.

As mentioned, it's worth thinking about putting in some extra timber to
raise the level and bump up the insulation while you're there.

Theo

On 31/10/2020 18:07, pinnerite wrote:
From around the beginning of February, Mrs P and I will be moving into a
bungalow that is in need of lot of work. I do not yet know how old it is
but I am guessing from between mid-60s to early 70s.

The loft has glass-fibre insulation and is only partialy boarded. I
intend extend the boarding. I boarded my current one with bits of
chipboard let over from work done years ago. Well that was 5/8" board.

Now (soon) I shall need to buy new. It looks as though 18 x 600 x 2400 is
the default today.

The thing is I always aligned board edges along the centre of the joists.
So that would require joists at 600mm.

My house wasn't completed until May 1972 and its joists are at
16" (406mm) centres. The "new" bungalow may be the same age. Should I be
concerned if I intend to lay them at right angles to the joists?

You would normally run the long axis of the boards perpendicular to the
joists. So you would only potentially need to trim an end of a board if
the joist spacing is out. The board to board joins have the T&G profile
and so don't need extra support.

(you can make them stronger still if you glue them, but that is usually
overkill).


--
Cheers,

John.

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

John Rumm wrote:

The board to board joins have the T&G profile and so don't need extra
support.

Stagger the joins, but a 1/4" tongue of weetabix doesn't have much
strength, so only tread where you can see screws into the joists unless
you're slimmer of the month ...

On Sun, 1 Nov 2020 07:29:08 +0000, Andy Burns wrote:

The board to board joins have the T&G profile and so don't need
extra
support.

Stagger the joins, but a 1/4" tongue of weetabix doesn't have much
strength,

True but the T&G on weetabix is more like an inch and half with quite
on offset between sides and the toungue/groove tapered.

--
Cheers
Dave.

Dave Liquorice wrote:

Andy Burns wrote:


a 1/4" tongue of weetabix doesn't have much strength,

True but the T&G on weetabix is more like an inch and half with quite
on offset between sides and the toungue/groove tapered.

My loft boards are 3/4" (green flooring chipboard is 22m or occasionally
38mm).

https://www.homebase.co.uk/chipboard-loft-panel-board-1220-x-320-x-18mm-3-pack_p404607

On Sunday, 1 November 2020 at 07:29:16 UTC, Andy Burns wrote:
John Rumm wrote:

The board to board joins have the T&G profile and so don't need extra
support.
Stagger the joins, but a 1/4" tongue of weetabix doesn't have much
strength, so only tread where you can see screws into the joists unless
you're slimmer of the month ...

Because the pitch of our roof trusses is a mere 22deg there is no part of our loft that you can stand up in. However, to enable me to crawl easily about the loft to do wiring I boarded the central portion so that I could easily crawl without getting tangled with the rock wool. I simply fastened 3 X 2s to the side of the trusses at 300mm above ceiling height and used chipboard loft boards as the floor. It did mean shortening every one of them and losing about 300mm each time also not helped by the uneven spacing of the trusses. It did reduce head room considerably with me just about able to kneel in the very centre but it made subsequent work so easy. Once we complete work in the loft which will involve dropping a couple of cables into the bathroom and providing a ventilation system for the bathroom I have no intention of using the loft.

Richard

My loft now only partly boarded has the insulation over the boarding as it
has to be a certain thickness and many houses simply do not have that space
unless the joists are mega thick!

Brian

--

This newsgroup posting comes to you directly from...
The Sofa of Brian Gaff...

Blind user, so no pictures please
Note this Signature is meaningless.!
"Tim Lamb" wrote in message
news
In message , pinnerite
writes
From around the beginning of February, Mrs P and I will be moving into a
bungalow that is in need of lot of work. I do not yet know how old it is
but I am guessing from between mid-60s to early 70s.

The loft has glass-fibre insulation and is only partialy boarded. I
intend extend the boarding. I boarded my current one with bits of
chipboard let over from work done years ago. Well that was 5/8" board.

Now (soon) I shall need to buy new. It looks as though 18 x 600 x 2400 is
the default today.

The thing is I always aligned board edges along the centre of the joists.
So that would require joists at 600mm.

My house wasn't completed until May 1972 and its joists are at
16" (406mm) centres. The "new" bungalow may be the same age. Should I be
concerned if I intend to lay them at right angles to the joists?

No. I use polyurethane glue to bond the joints but you might need to
consider access for moving/re-wiring light fittings etc.

Might be good to top up the insulation while you are there. I prefer
Rockwool. Much less irritating for a similar performance.

The electricians will be along shortly worrying about power cables buried
in insulation:-)

--
Tim Lamb

On Sun, 1 Nov 2020 09:55:56 +0000, Andy Burns wrote:

a 1/4" tongue of weetabix doesn't have much strength,

True but the T&G on weetabix is more like an inch and half with
quite
on offset between sides and the toungue/groove tapered.

My loft boards are 3/4" (green flooring chipboard is 22m or occasionally
38mm).

https://www.homebase.co.uk/chipboard...-1220-x-320-x-
18mm-3-pack_p404607

Er, so? You can clearly see the T&G that is much more than 1/4",
maybe nearer an inch on those boards, and the taper.

--
Cheers
Dave.

Dave Liquorice wrote:

https://www.homebase.co.uk/chipboard...-1220-x-320-x-
18mm-3-pack_p404607

Er, so? You can clearly see the T&G that is much more than 1/4",
maybe nearer an inch on those boards, and the taper.

How do you get a 1" thick tongue on a 3/4" thick board?

On 01/11/2020 11:23, Brian Gaff (Sofa) wrote:

My loft now only partly boarded has the insulation over the boarding as it
has to be a certain thickness and many houses simply do not have that space
unless the joists are mega thick!

Make the extra insulation polyurethane foam and provide extra sleeping
space.

--
Max Demian

On Sun, 1 Nov 2020 11:43:16 +0000, Andy Burns wrote:


https://www.homebase.co.uk/chipboard...-1220-x-320-x-
18mm-3-pack_p404607

Er, so? You can clearly see the T&G that is much more than 1/4",
maybe nearer an inch on those boards, and the taper.

How do you get a 1" thick tongue on a 3/4" thick board?

Ah, I see. 1" long, if you like. Less a easy to flex and spreads the
load.

--
Cheers
Dave.

On 01/11/2020 07:29, Andy Burns wrote:
John Rumm wrote:

The board to board joins have the T&G profile and so don't need extra
support.

Stagger the joins, but a 1/4" tongue of weetabix doesn't have much
strength, so only tread where you can see screws into the joists unless
you're slimmer of the month ...

Do you take similar care walking over a floor in a modern house? Because
the same arrangement of floor boards exists there.

Remember you are talking about a 2' wide board adjacent and interlocked
with another, spanning one joist space - so there is no reason for it to
give at the edge.


--
Cheers,

John.

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

John Rumm wrote:

Do you take similar care walking over a floor in a modern house? Because
the same arrangement of floor boards exists there.

Chip floorboards are 22m or 38mm though, compared to 18mm for loftboards.

Remember you are talking about a 2' wide board adjacent and interlocked
with another, spanning one joist space - so there is no reason for it to
give at the edge.

I have certainly managed to crack the odd tongue off my loftboards

On 01/11/2020 14:55, Andy Burns wrote:
John Rumm wrote:

Do you take similar care walking over a floor in a modern house?
Because the same arrangement of floor boards exists there.

Chip floorboards are 22m or 38mm though, compared to 18mm for loftboards.

Remember you are talking about a 2' wide board adjacent and
interlocked with another, spanning one joist space - so there is no
reason for it to give at the edge.

I have certainly managed to crack the odd tongue off my loftboards

18mm is also ok for floors

--
€œProgress is precisely that which rules and regulations did not foresee,€�

€“ Ludwig von Mises

In message , The Natural Philosopher
writes
On 01/11/2020 14:55, Andy Burns wrote:
John Rumm wrote:

Do you take similar care walking over a floor in a modern house?
Because the same arrangement of floor boards exists there.
Chip floorboards are 22m or 38mm though, compared to 18mm for
loftboards.

Remember you are talking about a 2' wide board adjacent and
interlocked with another, spanning one joist space - so there is no
reason for it to give at the edge.
I have certainly managed to crack the odd tongue off my loftboards

18mm is also ok for floors

ISTR 22mm is required for ground floor.


--
Tim Lamb

On 01/11/2020 09:55, Andy Burns wrote:
Dave Liquorice wrote:

Andy Burns wrote:


a 1/4" tongue of weetabix doesn't have much strength,

True but the T&G on weetabix is more like an inch and half with quite
on offset between sides and the toungue/groove tapered.

My loft boards are 3/4" (green flooring chipboard is 22m or occasionally
38mm).

https://www.homebase.co.uk/chipboard-loft-panel-board-1220-x-320-x-18mm-3-pack_p404607


My 1976 house has trusses and a 37 degree roof pitch, but I still
managed to get full size 8x2 t&g 18mm flooring chipboard through
the loft hatch.

It's a lot stronger than those 'weetabix' loft panels that B&Q
sell.

On 01/11/2020 15:23, The Natural Philosopher wrote:
On 01/11/2020 14:55, Andy Burns wrote:
John Rumm wrote:

Do you take similar care walking over a floor in a modern house?
Because the same arrangement of floor boards exists there.

Chip floorboards are 22m or 38mm though, compared to 18mm for loftboards.

Remember you are talking about a 2' wide board adjacent and
interlocked with another, spanning one joist space - so there is no
reason for it to give at the edge.

I have certainly managed to crack the odd tongue off my loftboards

18mm is also ok for floors


When the supporting joists are spaced at 450mm. New houses these
days have a 600mm spacing so they use 22mm chipboard flooring.

In article , John
Rumm writes
On 01/11/2020 07:29, Andy Burns wrote:
John Rumm wrote:

The board to board joins have the T&G profile and so don't need
extra support.
Stagger the joins, but a 1/4" tongue of weetabix doesn't have much
strength, so only tread where you can see screws into the joists
unless you're slimmer of the month ...

Do you take similar care walking over a floor in a modern house?
Because the same arrangement of floor boards exists there.

Remember you are talking about a 2' wide board adjacent and interlocked
with another, spanning one joist space - so there is no reason for it
to give at the edge.


+1
--
bert