My house (early 1900's semi) has a bedroom in the loft. I've no idea when
it was put there but by the look of the construction it was many moons ago.
The walls are t&g with some sort of fibreboard fixed to the front and then
woodchip. The ceiling is skimmed but I'm not sure what's underneath. I'm
pretty certain there's little, if any, insulation between the celing and the
roof tiles.

I'd like redo the walls and ceiling with plasterboard, inserting some
appropriate insulation and generally bringing things up to a more modern
standard.

Does anyone know how much I can change before I need to start implementing
things like the door closers on other rooms and the other things that are
required for new loft conversions? I'm going to call the local planning
dept but just wondered what other people's experiences have been?

TIA

Mark

Does anyone know how much I can change before I need to start implementing
things like the door closers on other rooms and the other things that are
required for new loft conversions?

Don't get too hung up about the building regulations. With a few notable
exceptions, they are usually very reasonable and may save your life.
Personally, I'd try to bring up the current standards where possible.

Are there any areas where there is likely to be a problem?

Door closers can just be rising butt hinges. You don't need ugly door
pushers.

Christian.

Does anyone know how much I can change before I need to start
implementing
things like the door closers on other rooms and the other things that
are
required for new loft conversions?

Don't get too hung up about the building regulations. With a few notable
exceptions, they are usually very reasonable and may save your life.
Personally, I'd try to bring up the current standards where possible.

Are there any areas where there is likely to be a problem?

I can absolutely see the point of smoke alarms and a suitable fire escape
route and so on. The room will be used by my kids so I'm not going to cut
those corners. What does concern me is that what might start out looking
like a DIY job - bit of reboarding, some Celotex here and there, touch of
plastering, will very quickly get out of control if I end up having to
strengthen the floor and so on!

Just goes to show that I need to do my homework before reaching for the
hammer.

Mark

What does concern me is that what might start out looking like a
DIY job - bit of reboarding, some Celotex here and there, touch of
plastering, will very quickly get out of control if I end up having
to strengthen the floor and so on!

How deep are the joists and how long is the span?

The insulation is definitely important, and quite involved. You must design
it properly or things can go wrong with condensation or fuel economy. Just
bunging on Celotex without understanding about how the moisture in the
vapour will behave is not the best technique.

You can get the roof much thinner with better u-Values if it is possible to
redo the roof covering. If so, then you can use an unventilated system
(saving 50mm), or even a warm roof system (this may be difficult on a semi
or terrace unless doing all houses, as it may affect the roof line).

For a loft conversion, you are allowed to drop a bit on the roof u-Value.

To see the vast variety of different possible roof constructions see:

http://www.insulation.kingspan.com/newdiv/pdf/k7.pdf

If you can't relay the tiles/slates, you'll be looking at the "Ventilated"
versions, which require tile vents and 50mm gap behind the insulation (fig
2a/2b). If you have 75mm rafters, you'd need 25mm between rafters and 75mm
underneath, although I'm not sure if this may result in condensation issues
with the top layer being smaller than the underslung one. With 100mm joists
it is a non-issue, as you'd be talking 50/50 split.

If you can re-lay, something like "Fully Filled Insulation Between Rafters"
with or without sarking board and tile battens. Typically you will have 75mm
rafters and 25mm board underneath, which should satisfy building control
(fig 1a or 1c). If you have 100mm rafters, you can get 0.27 uValue and
attach plasterboard direct to rafters. Although not good enough for new
construction, most BCOs would accept this for loft conversion work, although
having a thin layer of underslung insulation does prevent cold lines
appearing on the rafter lines, which can attract mould.

If you have a detached house and can overcome planning restrictions then
50mm/50mm unventilated warm roof between and above rafters might be
appropriate. This will give you full roof underneath with plasterboard
attached directly to joists, but will raise the roof, literally!

Christian.

"Christian McArdle" wrote in message
.net...
What does concern me is that what might start out looking like a DIY
job - bit of reboarding, some Celotex here and there, touch of
plastering, will very quickly get out of control if I end up having
to strengthen the floor and so on!

How deep are the joists and how long is the span?

They're 6"x2" at 14" centres and the longest span is 13'. The rafters are
4"x2".

The insulation is definitely important, and quite involved. You must
design
it properly or things can go wrong with condensation or fuel economy.
Just bunging on Celotex without understanding about how the moisture
in the vapour will behave is not the best technique.

I was aware of the condensation issue. The roof is tiled with no felt or
sarking.
Thanks for the link, lots of useful info.

For a loft conversion, you are allowed to drop a bit on the roof u-Value.

To see the vast variety of different possible roof constructions see:

http://www.insulation.kingspan.com/newdiv/pdf/k7.pdf

If you can re-lay, something like "Fully Filled Insulation Between
Rafters"
with or without sarking board and tile battens. Typically you will
have 75mm
rafters and 25mm board underneath, which should satisfy building
control (fig 1a or 1c). If you have 100mm rafters, you can get 0.27
uValue and attach plasterboard direct to rafters. Although not good
enough for new construction, most BCOs would accept this for loft
conversion work, although
having a thin layer of underslung insulation does prevent cold lines
appearing on the rafter lines, which can attract mould.

I'm not sure about relaying the tiles - I'll have to have a look at the
cost. Also, as it's a semi, I can't change the roof line. Hopefully the
100mm rafters opens up enough other options.

Mark

The rafters are 4"x2".

Well, without sarking, you might get away with an unventilated between
rafters only. The closed cell foam may even act as a form of sarking (but
with big holes in!). I don't know what the BCO would say, though.

How deep are the joists and how long is the span?

They're 6"x2" at 14" centres and the longest span is 13'.

Quick calculation to metric:

152mm x 51mm joists at 355mm centres at a span of 3.96m.

According to Part A, your joists are good for 3.27m. To reach 3.96m, you
need 195mm joists. However, it is likely that the limiting factor is floor
bounce, not final structural strength. Certainly, your 6" joists are vastly
better than what is normally found (i.e. 3" joists) which don't even make
the tables. A 4" joist (i.e. 38x97) would only allow 1.83m span.

Christian.

On Tue, 15 Jun 2004 13:11:15 GMT, a particular chimpanzee named "Mark
Walters" randomly hit the keyboard
and produced:

My house (early 1900's semi) has a bedroom in the loft. I've no idea when
it was put there but by the look of the construction it was many moons ago.

I'd like redo the walls and ceiling with plasterboard, inserting some
appropriate insulation and generally bringing things up to a more modern
standard.

Does anyone know how much I can change before I need to start implementing
things like the door closers on other rooms and the other things that are
required for new loft conversions? I'm going to call the local planning
dept but just wondered what other people's experiences have been?

Basically, as long as the work at no stage adversely alters the
structure or the means of escape in case of fire, then a Building
Regulations application won't be needed.

However, when you come to sell the house you may well be asked by your
buyer's solicitors for proof that a Building Regulations application
was submitted for the original work. If the work was carried out
after 1985 then you can apply for a Regularisation certificate. You
haven't said if the floor is adequate (not just boards laid over the
original 4" ceiling joists) or if there's a fixed stair leading to it
from the first floor landing, and the stairs enclosed from first to
ground floors. Self closers are the least of it.

Regularising a non compliant loft may involve a fair bit of work which
you may not be prepared to do, and would probably be more expensive
than starting from scratch. If you go with your proposed option you
should perhaps consider whether it's worth spending that money lining
and insulating that loft if it's all got to be ripped out before you
can sell your house.
--
Hugo Nebula
"The fact that no-one on the internet wants a piece of this
shows you just how far you've strayed from the pack".

Does anyone know how much I can change before I need to start
implementing
things like the door closers on other rooms and the other things that are
required for new loft conversions? I'm going to call the local planning
dept but just wondered what other people's experiences have been?

Basically, as long as the work at no stage adversely alters the
structure or the means of escape in case of fire, then a Building
Regulations application won't be needed.

I think I would like to improve the current fire escape options by
installing
a road accessible velux or similar. There is already a side window but
you need to get through a gate to get directly below it.

However, when you come to sell the house you may well be asked by your
buyer's solicitors for proof that a Building Regulations application
was submitted for the original work. If the work was carried out
after 1985 then you can apply for a Regularisation certificate. You
haven't said if the floor is adequate (not just boards laid over the
original 4" ceiling joists) or if there's a fixed stair leading to it
from the first floor landing, and the stairs enclosed from first to
ground floors. Self closers are the least of it.

There is a fixed staircase leading up to the room and it was certainly made
habitable before 1985.

The floor has proper fixed floorboards - the joists are 6"x2" - and appears
to be very stable. There's no obvious bounce and the lath and plaster
ceiling
of the room below has only a few minor cracks which I take to mean that
there's
not been a lot of movement.

Regularising a non compliant loft may involve a fair bit of work which
you may not be prepared to do, and would probably be more expensive
than starting from scratch. If you go with your proposed option you
should perhaps consider whether it's worth spending that money lining
and insulating that loft if it's all got to be ripped out before you
can sell your house.

Indeed.

Thanks

Mark.

"Christian McArdle" wrote in message
. net...
The rafters are 4"x2".

Well, without sarking, you might get away with an unventilated between
rafters only. The closed cell foam may even act as a form of sarking (but
with big holes in!). I don't know what the BCO would say, though.

How deep are the joists and how long is the span?

They're 6"x2" at 14" centres and the longest span is 13'.

Quick calculation to metric:

152mm x 51mm joists at 355mm centres at a span of 3.96m.

According to Part A, your joists are good for 3.27m. To reach 3.96m, you
need 195mm joists. However, it is likely that the limiting factor is floor
bounce, not final structural strength. Certainly, your 6" joists are
vastly
better than what is normally found (i.e. 3" joists) which don't even make
the tables. A 4" joist (i.e. 38x97) would only allow 1.83m span.

Thanks - definitely time to ring the local BCO and get some advice.

Mark

I think I would like to improve the current fire escape options by
installing a road accessible velux or similar.

Yes. Given that you already have 6" joists, I'd be much more inclined to
improve fire safety and insulation than joist thickness. The 6" joists are
probably no worse than many Victorian properties would have had normally and
people don't go round replacing those.

Christian.

On Wed, 16 Jun 2004 10:17:31 GMT, a particular chimpanzee named "Mark
Walters" randomly hit the keyboard
and produced :

There is a fixed staircase leading up to the room and it was certainly made
habitable before 1985.

The floor has proper fixed floorboards - the joists are 6"x2" - and appears
to be very stable. There's no obvious bounce and the lath and plaster
ceiling
of the room below has only a few minor cracks which I take to mean that
there's
not been a lot of movement.

Apologies, I didn't read the entire thread before replying. It sounds
like it was converted legally (or at least, as near as damnit to the
requirements at the time), so you only need to concern yourself with
upgrading the insulation. A building regulations application would be
required for adding a Velux window, but only for the structural work
in trimming the rafters, and to control the heat loss through the
window.