I'm planning on boarding out our loft so we can store some boxes up there
easily. The joists are 4"x2" with a 30cm gap between them. It's a 1930's
semi BTW. The joists appear to be half the length of the house, with them
meeting (and joined I assume) over the middle wall of the house. This has a
(measured from outside wall to middle wall) 11' span at the front of the
house and a 13' span at the back of the house.

The way the loft and roof is layed out, there's a large centre part which
would be best for storage due to height of roof and ease of access into the
loft. This centre of this area is over the middle wall.

Any idea what sort of loading may be possible? I would prefer not to have
to add anything extra to the joists if I can help it. It shouldn't be used
for anything more than storage of boxes, and not terribly heavy ones at that
(as I have to carry them up the ladder!).

I've heard that 3x2 flex a lot and therefore aren't really suitable for
boarding directly out onto, but does the extra 1" make much difference with
my 4x2's? Obviously, thicker joists would allow for more insulation - but
at the moment, I'm really looking for doing it with as minimal work (ie.
cost) as possible, and therefore really want to know about the loading of
what I've already got.

Thanks

D

--
To send email to me - remove references to NoSpam, and Spammer from my email
address.

"David Hearn" wrote in message
...
I'm planning on boarding out our loft so we can store some boxes up there
easily. The joists are 4"x2" with a 30cm gap between them. It's a 1930's
semi BTW. The joists appear to be half the length of the house, with them
meeting (and joined I assume) over the middle wall of the house. This has
a
(measured from outside wall to middle wall) 11' span at the front of the
house and a 13' span at the back of the house.

The way the loft and roof is layed out, there's a large centre part which
would be best for storage due to height of roof and ease of access into
the
loft. This centre of this area is over the middle wall.

Any idea what sort of loading may be possible? I would prefer not to have
to add anything extra to the joists if I can help it. It shouldn't be
used
for anything more than storage of boxes, and not terribly heavy ones at
that
(as I have to carry them up the ladder!).

I've heard that 3x2 flex a lot and therefore aren't really suitable for
boarding directly out onto, but does the extra 1" make much difference
with
my 4x2's? Obviously, thicker joists would allow for more insulation -
but
at the moment, I'm really looking for doing it with as minimal work (ie.
cost) as possible, and therefore really want to know about the loading of
what I've already got.

http://www.hmso.gov.uk/si/si2000/20002531.htm

This contains the tables which calculate acceptable loadings.

My loft has 4*2s on 14" (36cm) spacings and longest span of about 22' -
there is a stud wall under this but I don't know if it is load bearing at
all - certainly the lounge runs front to back without any load bearing wall.

There is a beam above the joists and at right angles but I don't know if
this is connected to each joist and carrying part of the load.

The house is 1930's and the loft was part boarded when we bought it.
I have added more boarding for more storage.

The loft seems fine with boards - no sign of the ceiling sagging etc. - but
on the other hand the next door neighbour had someone in to do engineering
drawings for a loft conversion and he had an attack of the "Never seen one
like that before - I suggest you move all your stuff round the edges to
reduce the loading."

I am pretty sure the beam sizes are well outside current building regs. for
flooring, but then again the regs. allow for cast iron baths etc.

Seems O.K. for us but then we could be lving on borrowed time.

As for increasing the thickness of the joists, I suspect you can't get the
extra thickness over the side walls and under the existing roof. This is why
loft conversions tend to install a new, independant load bearing structure.

I presume that if you halved the spacing i.e. inserted a 2*4 between each
current joist to go down to 15cm spacing you would be O.K. but this is a
very expensive option given the price of timber nowadays.

HTH

Dave R

Might be a silly question but ... how would you get the new timber joists
into the loft ? Im assuming here that the joist must run the whole width of
the house. Or can they be split on an internal loadbearing wall ? Even so
I think I would stuggle in my house.

Andy F


"David Hemmings" wrote in message
...
On Mon, 3 Nov 2003 12:58:54 -0000, "David W.E. Roberts"
wrote:



http://www.hmso.gov.uk/si/si2000/20002531.htm

This contains the tables which calculate acceptable loadings.

My loft has 4*2s on 14" (36cm) spacings and longest span of about 22' -
there is a stud wall under this but I don't know if it is load bearing at
all - certainly the lounge runs front to back without any load bearing
wall.

There is a beam above the joists and at right angles but I don't know if
this is connected to each joist and carrying part of the load.

The house is 1930's and the loft was part boarded when we bought it.
I have added more boarding for more storage.

The loft seems fine with boards - no sign of the ceiling sagging etc. -
but
on the other hand the next door neighbour had someone in to do
engineering
drawings for a loft conversion and he had an attack of the "Never seen
one
like that before - I suggest you move all your stuff round the edges to
reduce the loading."

I am pretty sure the beam sizes are well outside current building regs.
for
flooring, but then again the regs. allow for cast iron baths etc.

Seems O.K. for us but then we could be lving on borrowed time.

As for increasing the thickness of the joists, I suspect you can't get
the
extra thickness over the side walls and under the existing roof. This is
why
loft conversions tend to install a new, independant load bearing
structure.

I presume that if you halved the spacing i.e. inserted a 2*4 between each
current joist to go down to 15cm spacing you would be O.K. but this is a
very expensive option given the price of timber nowadays.

HTH

Dave R


But the best way to quickly add that etra load bearing capability with
the least amount of effort, so assuming 7.2m front to back that should
only be approx £7.50 per extra joist run. A usual semi should be
somewhere around 15 runs with this spacing. ANd remember if you can to
place the heaviest items near the supporting wall and the wall where
you semis meet - this is where my storage tanks are.

Also bear in mind that usual spacings are now 16" centres (14"
spacing) which would affect the required size of joist.

by inserting another joist the spacings would be reduced to 13cm not
15 (remember the joists are 47mm wide)

My loft also has approx 12" spacings but also has various places that
are cross joisted (3x2) and also some with more joists sitting on top
of existing joists (4x2) although i think the latter sitting over the
main supportiung wall had the origianl cold water tank on it -which i
need to cut up to remove at some point.

My gas installation people sat the pipework in the loft on top of the
3x2 cross joists so boarding out my loft is going to be an absolute
nightmare - i will try to make it at two levels, which will be an
infinite improvement over the current state of affairs.

"Andy Farrall" wrote in message
...
Might be a silly question but ... how would you get the new timber joists
into the loft ? Im assuming here that the joist must run the whole width
of
the house. Or can they be split on an internal loadbearing wall ? Even
so
I think I would stuggle in my house.

Andy F


"David Hemmings" wrote in message
...
On Mon, 3 Nov 2003 12:58:54 -0000, "David W.E. Roberts"
wrote:



http://www.hmso.gov.uk/si/si2000/20002531.htm

This contains the tables which calculate acceptable loadings.

My loft has 4*2s on 14" (36cm) spacings and longest span of about 22' -
there is a stud wall under this but I don't know if it is load bearing
at
all - certainly the lounge runs front to back without any load bearing
wall.

There is a beam above the joists and at right angles but I don't know
if
this is connected to each joist and carrying part of the load.

The house is 1930's and the loft was part boarded when we bought it.
I have added more boarding for more storage.

The loft seems fine with boards - no sign of the ceiling sagging etc. -
but
on the other hand the next door neighbour had someone in to do
engineering
drawings for a loft conversion and he had an attack of the "Never seen
one
like that before - I suggest you move all your stuff round the edges to
reduce the loading."

I am pretty sure the beam sizes are well outside current building regs.
for
flooring, but then again the regs. allow for cast iron baths etc.

Seems O.K. for us but then we could be lving on borrowed time.

As for increasing the thickness of the joists, I suspect you can't get
the
extra thickness over the side walls and under the existing roof. This
is
why
loft conversions tend to install a new, independant load bearing
structure.

I presume that if you halved the spacing i.e. inserted a 2*4 between
each
current joist to go down to 15cm spacing you would be O.K. but this is
a
very expensive option given the price of timber nowadays.

HTH

Dave R


But the best way to quickly add that etra load bearing capability with
the least amount of effort, so assuming 7.2m front to back that should
only be approx £7.50 per extra joist run. A usual semi should be
somewhere around 15 runs with this spacing. ANd remember if you can to
place the heaviest items near the supporting wall and the wall where
you semis meet - this is where my storage tanks are.

Also bear in mind that usual spacings are now 16" centres (14"
spacing) which would affect the required size of joist.

by inserting another joist the spacings would be reduced to 13cm not
15 (remember the joists are 47mm wide)

My loft also has approx 12" spacings but also has various places that
are cross joisted (3x2) and also some with more joists sitting on top
of existing joists (4x2) although i think the latter sitting over the
main supportiung wall had the origianl cold water tank on it -which i
need to cut up to remove at some point.

My gas installation people sat the pipework in the loft on top of the
3x2 cross joists so boarding out my loft is going to be an absolute
nightmare - i will try to make it at two levels, which will be an
infinite improvement over the current state of affairs.




Take the opportunity to fit a skylight.

"gaz" wrote in message
...

"Andy Farrall" wrote in message
...
Might be a silly question but ... how would you get the new timber
joists
into the loft ? Im assuming here that the joist must run the whole
width
of
the house. Or can they be split on an internal loadbearing wall ? Even
so
I think I would stuggle in my house.

Andy F


"David Hemmings" wrote in message
...
On Mon, 3 Nov 2003 12:58:54 -0000, "David W.E. Roberts"
wrote:



http://www.hmso.gov.uk/si/si2000/20002531.htm

This contains the tables which calculate acceptable loadings.

My loft has 4*2s on 14" (36cm) spacings and longest span of about
22' -
there is a stud wall under this but I don't know if it is load
bearing
at
all - certainly the lounge runs front to back without any load
bearing
wall.

There is a beam above the joists and at right angles but I don't know
if
this is connected to each joist and carrying part of the load.

The house is 1930's and the loft was part boarded when we bought it.
I have added more boarding for more storage.

The loft seems fine with boards - no sign of the ceiling sagging
etc. -
but
on the other hand the next door neighbour had someone in to do
engineering
drawings for a loft conversion and he had an attack of the "Never
seen
one
like that before - I suggest you move all your stuff round the edges
to
reduce the loading."

I am pretty sure the beam sizes are well outside current building
regs.
for
flooring, but then again the regs. allow for cast iron baths etc.

Seems O.K. for us but then we could be lving on borrowed time.

As for increasing the thickness of the joists, I suspect you can't
get
the
extra thickness over the side walls and under the existing roof. This
is
why
loft conversions tend to install a new, independant load bearing
structure.

I presume that if you halved the spacing i.e. inserted a 2*4 between
each
current joist to go down to 15cm spacing you would be O.K. but this
is
a
very expensive option given the price of timber nowadays.

HTH

Dave R


But the best way to quickly add that etra load bearing capability with
the least amount of effort, so assuming 7.2m front to back that should
only be approx £7.50 per extra joist run. A usual semi should be
somewhere around 15 runs with this spacing. ANd remember if you can to
place the heaviest items near the supporting wall and the wall where
you semis meet - this is where my storage tanks are.

Also bear in mind that usual spacings are now 16" centres (14"
spacing) which would affect the required size of joist.

by inserting another joist the spacings would be reduced to 13cm not
15 (remember the joists are 47mm wide)

My loft also has approx 12" spacings but also has various places that
are cross joisted (3x2) and also some with more joists sitting on top
of existing joists (4x2) although i think the latter sitting over the
main supportiung wall had the origianl cold water tank on it -which i
need to cut up to remove at some point.

My gas installation people sat the pipework in the loft on top of the
3x2 cross joists so boarding out my loft is going to be an absolute
nightmare - i will try to make it at two levels, which will be an
infinite improvement over the current state of affairs.




Take the opportunity to fit a skylight.

Kind of takes away from the original point of doing it as cheaply and easily
as possible. So, to board out the loft I need to actually add 15 4x2's @
£7.50 each (£112), plus boarding costs, and also add a skylight...
Sounds more like a proper conversion every minute.

Thanks for all the advice - I'll bear it in mind once I get round to doing
it (and figuring out how to fit in a ladder which needs 50-60cm height
above it - probably have to use a folding wooden ladder which uses less
height, but a larger access hole which is a problem due to the T&G cladding
someone put on the ceiling below which introduces more problems...)

Thanks

D

"gaz" wrote in message
...


Take the opportunity to fit a skylight.



Alternatively, if you can't wangle them through the trap door, you could
temporarily remove a few roof tiles just above the eaves and peel back the
felt. Should be easy enough to reinstate once the joists are safely inside.

Roger

"David Hearn" wrote in message
...
I'm planning on boarding out our loft so we can store some boxes up there
easily. The joists are 4"x2" with a 30cm gap between them. It's a 1930's
semi BTW. The joists appear to be half the length of the house, with them
meeting (and joined I assume) over the middle wall of the house. This has
a
(measured from outside wall to middle wall) 11' span at the front of the
house and a 13' span at the back of the house.

The way the loft and roof is layed out, there's a large centre part which
would be best for storage due to height of roof and ease of access into
the
loft. This centre of this area is over the middle wall.

Any idea what sort of loading may be possible? I would prefer not to have
to add anything extra to the joists if I can help it. It shouldn't be
used
for anything more than storage of boxes, and not terribly heavy ones at
that
(as I have to carry them up the ladder!).

I've heard that 3x2 flex a lot and therefore aren't really suitable for
boarding directly out onto, but does the extra 1" make much difference
with
my 4x2's? Obviously, thicker joists would allow for more insulation -
but
at the moment, I'm really looking for doing it with as minimal work (ie.
cost) as possible, and therefore really want to know about the loading of
what I've already got.

Thanks

D


This site gives a lot of information on the subject.

http://www.diydoctor.org.uk/projects...ring_walls.htm

"David Hearn" wrote in message
...
I'm planning on boarding out our loft so we can store some boxes up there
easily. The joists are 4"x2" with a 30cm gap between them. It's a 1930's
semi BTW. The joists appear to be half the length of the house, with them
meeting (and joined I assume) over the middle wall of the house. This has
a
(measured from outside wall to middle wall) 11' span at the front of the
house and a 13' span at the back of the house.


4"x2" and 30cm (assuming your mix of units is correct)

Maximum unsupported span for standard loading would be 1.98m .... so your
13' span already exceeds the loading that is allowed nowadays on joists.

OK .. your house is safe as dead load is probably just ceiling boards -
hopefully any water tanks have supports over a loadbearing wall.

But the joists ain't going to take any load from above.

Even boarding out with sheet material is high risk, the dead load of the
sheets would be too high.

If it were my place as the spacing is low at 300mm ... I would be happy to
deck out in t&g 18mm wheyrock, screwed at 150mm centres.
This would spread the load well enough for storage of light weight boxes.

A thought for you ... if joists are only 4" deep and you want to board over
what about the insulation ? presumably you still have the 1930's cold roof
construction and have rolled out insulation between joists - and this must
be no more than 4" (or you couldn't board)

This is VERY poor insulation, and you would be well advised to send your
money on increasing depth of that instead of boarding out.

I have 450mm depth in my place.


Rick

"Rick Hughes" wrote in message
...

"David Hearn" wrote in message
...
I'm planning on boarding out our loft so we can store some boxes up
there
easily. The joists are 4"x2" with a 30cm gap between them. It's a
1930's
semi BTW. The joists appear to be half the length of the house, with
them
meeting (and joined I assume) over the middle wall of the house. This
has
a
(measured from outside wall to middle wall) 11' span at the front of the
house and a 13' span at the back of the house.


4"x2" and 30cm (assuming your mix of units is correct)

Maximum unsupported span for standard loading would be 1.98m .... so your
13' span already exceeds the loading that is allowed nowadays on joists.

OK .. your house is safe as dead load is probably just ceiling boards -
hopefully any water tanks have supports over a loadbearing wall.

But the joists ain't going to take any load from above.

Even boarding out with sheet material is high risk, the dead load of the
sheets would be too high.

If it were my place as the spacing is low at 300mm ... I would be happy to
deck out in t&g 18mm wheyrock, screwed at 150mm centres.
This would spread the load well enough for storage of light weight boxes.

A thought for you ... if joists are only 4" deep and you want to board
over
what about the insulation ? presumably you still have the 1930's cold
roof
construction and have rolled out insulation between joists - and this must
be no more than 4" (or you couldn't board)

This is VERY poor insulation, and you would be well advised to send your
money on increasing depth of that instead of boarding out.

I have 450mm depth in my place.

Thanks for your advice. I may well add some more joists (possibly at 90
degrees to current ones) to increase the depth of insulation. In places,
there are already some 4x2 at 90 degrees (to stop spread I think) and it
would be good to try and board out at a level height. 4" of insulation is
poor, and I'd like to improve it.

What is wheyrock? I was thinking about 18mm chipboard (I have some packs
from our old place which we didn't use). A quick google says its a
composite floor decking - but I've never seen it or know what its like. Is
it much lighter/stronger than chipboard? What's the sort of cost of it?

Thanks

D

What is wheyrock? I was thinking about 18mm chipboard (I have some packs
from our old place which we didn't use). A quick google says its a
composite floor decking - but I've never seen it or know what its like.
Is
it much lighter/stronger than chipboard? What's the sort of cost of it?

sorry, should have been clear - Wheyrock is a trade name like Thermos for
vacuum flasks ... I refer to 18mm waterproof T&G flooring grade chipboard.

Rick

ummm not waterproof, but water resistant EN312-5 or P5, but in a loft
P4 should be adequate and should be about a pound a sheet cheaper (£5
vs £6 per 8x2 board)


I agree I used the wrong word, it's made with waterproof glue - but water
resistant is the term I should have used... on new floors I use phenlioc
coated wheyrock, that will take a lot more water than water resistant board.

Rick

"David Hemmings" wrote in message
...
On Fri, 7 Nov 2003 20:14:33 +0000 (UTC), "Rick Hughes"
wrote:


What is wheyrock? I was thinking about 18mm chipboard (I have some
packs
from our old place which we didn't use). A quick google says its a
composite floor decking - but I've never seen it or know what its like.
Is
it much lighter/stronger than chipboard? What's the sort of cost of
it?

sorry, should have been clear - Wheyrock is a trade name like Thermos for
vacuum flasks ... I refer to 18mm waterproof T&G flooring grade
chipboard.

Rick

ummm not waterproof, but water resistant EN312-5 or P5, but in a loft
P4 should be adequate and should be about a pound a sheet cheaper (£5
vs £6 per 8x2 board)

Ahh, so the £3.90 + VAT (£4.58 inc) is a good price for P4 boarding (quote
given on Friday - with them not trying to beat another price). And £3.96 +
VAT for P5 is also a good price then (quoted on an leaflet advertising their
new store I've got from the same local merchants, valid until 31st Dec).

Wondering whether to use P5 seeing as the roof is unlined.... just in
case....

Total number of boards I need for the main section is 11. Need another 10
for the 2 sided portions, so even if £1 extra per board, that's only an
extra £21 - better that than having problems should there be a small drip or
something.

D

"David Hemmings" wrote in message
...
On Sun, 9 Nov 2003 13:13:49 -0000, "David Hearn"
wrote:


"David Hemmings" wrote in message
.. .
On Fri, 7 Nov 2003 20:14:33 +0000 (UTC), "Rick Hughes"
wrote:



ummm not waterproof, but water resistant EN312-5 or P5, but in a loft
P4 should be adequate and should be about a pound a sheet cheaper (£5
vs £6 per 8x2 board)

Ahh, so the £3.90 + VAT (£4.58 inc) is a good price for P4 boarding
(quote
given on Friday - with them not trying to beat another price). And £3.96
+
VAT for P5 is also a good price then (quoted on an leaflet advertising
their
new store I've got from the same local merchants, valid until 31st Dec).

Wondering whether to use P5 seeing as the roof is unlined.... just in
case....

Total number of boards I need for the main section is 11. Need another
10
for the 2 sided portions, so even if £1 extra per board, that's only an
extra £21 - better that than having problems should there be a small drip
or
something.

D

Yes good price if it includes delivery, make sure you get an en312
stamp as some boards are not up to spec.

for such a small price extra the peace of mind you will receive should
definitely make it worth it...

Yep - free delivery on orders over £30. Finally we've got a wood yard in
Guildford!! Don't have to rely on B&Q now.

D