In the loft in my (end of) terrace house the end of the roof is square
(not slanted like a semi-detached house).

Inside to support the wooden uprights is a long beam on each side
which runs from left to right 1/2 way up the wooden uprights obviously
to stop them sagging in the middle. This beam is very thick in excess
if 12" I guess so if I were to convert the attic it would intrude in
the interior space.

Is it normal to leave these beams in or replace them with something
thinner (steel?) I know the thickness of all the insulation etc will
be quite thick but not sure if it will be as thick as the beam.

The house is a 1935 red brick victorian style affair.

405 TD Estate wrote:
In the loft in my (end of) terrace house the end of the roof is square
(not slanted like a semi-detached house).


Gable end rather than hipped?

Inside to support the wooden uprights is a long beam on each side
which runs from left to right 1/2 way up the wooden uprights obviously
to stop them sagging in the middle. This beam is very thick in excess
if 12" I guess so if I were to convert the attic it would intrude in
the interior space.

Purlins?

What 'wooden uprights'?

Normally there are angled rafters and a ridge, and purlin half way along
the rafters to stop them bowing laterally, not to support them.

If vertical support is required that's normally done by verticals to the
ceiling joists, or W bracing from the rafter centers to the roof center
line under the ridge.


Is it normal to leave these beams in or replace them with something
thinner (steel?) I know the thickness of all the insulation etc will
be quite thick but not sure if it will be as thick as the beam.


In the absence of photos, get a structural engineer in. These sound
MASSIVE for purlins. Something does not compute.


The house is a 1935 red brick victorian style affair.


1935 was about 33 years after Victoria died. as it happens..if its 1935
they were NOT known for massive over-engineering, so something is going
on here that needs more investigation.

Phone up local structural engineers and ask them to take a look, (report
not needed less cost) - it's too much of a structural thing to make a
guess on the Internet..and the implications of getting it badly wrong
are expensive and dangerous.

405 TD Estate wrote:

In the loft in my (end of) terrace house the end of the roof is square
(not slanted like a semi-detached house).

You mean there is a gable end wall, and not a hipped roof by the sounds
of it.

Inside to support the wooden uprights is a long beam on each side
which runs from left to right 1/2 way up the wooden uprights obviously
to stop them sagging in the middle. This beam is very thick in excess
if 12" I guess so if I were to convert the attic it would intrude in
the interior space.

If by "uprights" you mean the slanted beams that run up the slope of the
roof (usually known as rafters), then what you describe is a purlin. Its
purpose is as you say to stop the rafters sagging under the weight of
the tiles etc.

Is it normal to leave these beams in or replace them with something
thinner (steel?) I know the thickness of all the insulation etc will
be quite thick but not sure if it will be as thick as the beam.

Depends on the exact position, and if you are having dwarf walls at the
edges. The dwarf wall can replace the purlin in some cases. You may find
they are behind where you want a wall anyway.

I had a purlin like this:
http://www.internode.co.uk/loft/images/goal.jpg

Picture taken shortly before I took a chainsaw to the whole rear roof
section ;-)

At the front there was a matching one. This was replaced with a swarf
wall that intercepted the rafters a few inches lower:

http://www.internode.co.uk/loft/images/dwarfwall.jpg

This is load bearing and transfers the roof load to the new strengthened
floor.


--
Cheers,

John.

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

On Sep 21, 12:12 pm, 405 TD Estate wrote:
In the loft in my (end of) terrace house the end of the roof is square
(not slanted like a semi-detached house).

It has a gable rather than a hipped roof. Nothing to do with it's
attachment, or otherwise.

MBQ

John Rumm wrote:
405 TD Estate wrote:

In the loft in my (end of) terrace house the end of the roof is square
(not slanted like a semi-detached house).

You mean there is a gable end wall, and not a hipped roof by the sounds
of it.

Inside to support the wooden uprights is a long beam on each side
which runs from left to right 1/2 way up the wooden uprights obviously
to stop them sagging in the middle. This beam is very thick in excess
if 12" I guess so if I were to convert the attic it would intrude in
the interior space.

If by "uprights" you mean the slanted beams that run up the slope of the
roof (usually known as rafters), then what you describe is a purlin. Its
purpose is as you say to stop the rafters sagging under the weight of
the tiles etc.


It is not that effective at that. I thought the real problem was that
the rafters, under compession, would suffer Euler collapse. The purlin
stops that neatly. As indeed does nailing battens across them. Or indeed
a sheet of ply over the whole of the rafters :-)



Is it normal to leave these beams in or replace them with something
thinner (steel?) I know the thickness of all the insulation etc will
be quite thick but not sure if it will be as thick as the beam.

Depends on the exact position, and if you are having dwarf walls at the
edges. The dwarf wall can replace the purlin in some cases. You may find
they are behind where you want a wall anyway.

I had a purlin like this:
http://www.internode.co.uk/loft/images/goal.jpg

Picture taken shortly before I took a chainsaw to the whole rear roof
section ;-)

Thats the spirit!

At the front there was a matching one. This was replaced with a swarf
wall that intercepted the rafters a few inches lower:

http://www.internode.co.uk/loft/images/dwarfwall.jpg


I THINK you mean a DWARF wall ?


This is load bearing and transfers the roof load to the new strengthened
floor.

And is very nicely done if I may say so, and ideal for a loft conversion
anyway.

The Natural Philosopher wrote:

If by "uprights" you mean the slanted beams that run up the slope of
the roof (usually known as rafters), then what you describe is a
purlin. Its purpose is as you say to stop the rafters sagging under
the weight of the tiles etc.

It is not that effective at that. I thought the real problem was that
the rafters, under compession, would suffer Euler collapse. The purlin
stops that neatly. As indeed does nailing battens across them. Or indeed
a sheet of ply over the whole of the rafters :-)

Well, I should add that it does not achieve this on its own, it in turn
needs supporting by something. In the style of property described this
is usually by struts from the mid section of the purlin, at an angle
down to a plate over the centre spine wall of the property. The lateral
thrust of the strut being counterbalanced by that of the opposing member
for the other side of the roof.

These struts and the purlin do prevent sagging of the rafters by quite a
significant amount though. When I did my roof, having partially de-tiled
the rear section of roof that was to be removed, we took out the purlin
strut. The centre span of the rafters immediately fell by over 4" - and
that was without the full weight of tiles on.

I had a purlin like this:
http://www.internode.co.uk/loft/images/goal.jpg

Picture taken shortly before I took a chainsaw to the whole rear roof
section ;-)

Thats the spirit!

Was fun that bit... ten mins work, a whole world of space appeared that
had been just waiting to be set free!

At the front there was a matching one. This was replaced with a swarf
wall that intercepted the rafters a few inches lower:

http://www.internode.co.uk/loft/images/dwarfwall.jpg


I THINK you mean a DWARF wall ?

;-) Yup, I expect a swarf one could prove quite feeble!

This is load bearing and transfers the roof load to the new
strengthened floor.

And is very nicely done if I may say so, and ideal for a loft conversion
anyway.

Ta. Seems to be holding so far at least! ;-)

--
Cheers,

John.

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

John Rumm wrote:
The Natural Philosopher wrote:

I had a purlin like this:
http://www.internode.co.uk/loft/images/goal.jpg

Picture taken shortly before I took a chainsaw to the whole rear roof
section ;-)

Thats the spirit!

Was fun that bit... ten mins work, a whole world of space appeared that
had been just waiting to be set free!

So you didn't feel even the *slightest* hint of trepidation as you
started cutting...?!

David

Lobster wrote:
John Rumm wrote:
The Natural Philosopher wrote:

I had a purlin like this:
http://www.internode.co.uk/loft/images/goal.jpg

Picture taken shortly before I took a chainsaw to the whole rear
roof section ;-)

Thats the spirit!

Was fun that bit... ten mins work, a whole world of space appeared
that had been just waiting to be set free!

So you didn't feel even the *slightest* hint of trepidation as you
started cutting...?!

Only in the sense I remember thinking, I wish I had a pair of ballistic
nylon trousers!
--
Cheers,

John.

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