Hi everyone,

I am looking to do a loft conversion in my house, but the roof is
supported with trussed rafters. I am looking for some advice on how to
create an alternative support for the roof so i can take take these
out and create some usable space. I have taken a few pictures and made
a drawing of the roof. I can supply measurements of the timber pieces.

thanks for any advice

pictures he

http://branoblogging.blogspot.com/20...-pictures.html

Brano wrote:
Hi everyone,

I am looking to do a loft conversion in my house, but the roof is
supported with trussed rafters. I am looking for some advice on how to
create an alternative support for the roof so i can take take these
out and create some usable space. I have taken a few pictures and made
a drawing of the roof. I can supply measurements of the timber pieces.

thanks for any advice

pictures he

http://branoblogging.blogspot.com/20...-pictures.html

Matchwood needs to be replaced with proper wood trusses that dont need
lots of latticework to survive. That means either replacing the whole
roof structure, or else cutting the matchsticks out one truss at a time
and reinforcing whats there to make it strong enough. You'd need some
qualified advice on doing that.

Also check your headroom, you lose some during a conversion.


NT

Brano wrote:
Hi everyone,

I am looking to do a loft conversion in my house, but the roof is
supported with trussed rafters. I am looking for some advice on how to
create an alternative support for the roof so i can take take these
out and create some usable space. I have taken a few pictures and made
a drawing of the roof. I can supply measurements of the timber pieces.

thanks for any advice

pictures he

http://branoblogging.blogspot.com/20...-pictures.html

Brano,

Sorry to rain on the parade, but if you have to ask that question here, you
are not really proficient to do the work.

You are talking about major structural changes, and with the roof timbers
and tiles alone weighing in at around twenty tons, then if you make a
mistake, you wil have a big headache to sort out - and remember, a decent
fall of snow can add a few more tons to that!

You will also require to insert new floor joists etc to carry the loading -
along with building reg approval and possibly planning permission.

My advice is to consult either a structural engineer, architect or loft
conversion specialist for further advice.



Brian G

"Brian G" wrote in message
...

mistake, you wil have a big headache to sort out - and remember, a decent
fall of snow can add a few more tons to that!

That's "summer" these days isn't it ;-)

Cheers
Dan.

"Brano" wrote ...
I am looking to do a loft conversion in my house, but the roof is
supported with trussed rafters. I am looking for some advice on how to
create an alternative support for the roof so i can take take these
out and create some usable space. I have taken a few pictures and made
a drawing of the roof. I can supply measurements of the timber pieces.

Unfortunately Brano, in the late '60's / early '70's penny-pinching builders
started adopting the "fink truss" roof, found in your house. This was
invented in the 1940's during the War Effort to save decent timber for
building aircraft etc. by reducing the strength (read size) of timber for
roofing. There was no consideratioin given to the likelihood of anyone
wanting to use the space in the loft, and other aspects of houses built this
way are affected - the ceiling joists are designed only to support the
plaster and loft insulation, for instance (water tanks often have to be sat
on specially constructed platforms of "proper sturdy wood" to pass the loads
to the walls), the upper wall structure is designed to take smaller dead
loads as the fink truss is lighter by far than the traditional "cut roof"
joists anad purlins. A by-product of this change is that roof pitches
decreased from around 45 degrees to between 20 and 30 degrees, with a
corresponding loss of loft height - to make an usable room one needs a
height of at least 7' over most of the floor.

To even consider a loft conversion, you *need* the services of a structural
engineer as the fink truss is an unitary structure - all the elements are
required to share the loadings - and removing one element will quite likely
mean that other elements are taken beyond their permitted loads, with the
risk of collapse... it'll need a complete new roof strucure of full-sized
timber, probaly steelwork as (for example) the spans betwen supports for the
roof will exceed the building regulation defined maximum for unsupported
purlins . While designing the new roof structure it''s likely that the
architect / structural engineer will consider that the wall structure isn't
adequate for the new loadings (particularly if there are stud-and-plaster
internal walls or timber-frame external walls, requiring additional
structural work down to foundation level... you'll need to install new floor
joists alongside the existing ceiling joists (which can't be removed in
advance, as they tie the building walls together and prevent the outward
roof load toppling them), probably 8" by 2" minimum, raising the current
"floor" level by 4" or so. The increase in "floor" height will reduce
headroom, meaning you'l need to either raise the ridge line or install
dormer windows... it goes on and on.

G/f and I are in the final stages of buying a house together, with the
possibility (or probability) of converting the loft firmly in mind - we
eliminated anything built since 1960 - 1970 for just these reasons!

My considered advice is:
..
..
..
Move house [1]. It'll be cheaper and less disruptive.

Dave H.
(The engineer formerly known as Homeless)


[1] to a nice trad house made of bricks with a nice trad roof made of 8x2"
and bigger timbers

Brano wrote:

I am looking to do a loft conversion in my house, but the roof is
supported with trussed rafters. I am looking for some advice on how to
create an alternative support for the roof so i can take take these
out and create some usable space. I have taken a few pictures and made
a drawing of the roof. I can supply measurements of the timber pieces.

One solution is to simply ignore the existing woodwork and build
yourself a new roof structure inside the loft using more traditional
joinery (i.e. rafters, purlins etc). Since the use of trusses allows
wide roof spans without need for an intermediat supporting wall it may
also be that you have nothing to support an traditional loft stucture.
If this were the case then you would probably need do find a way of
intalling a beam across the middle of the properties.

--
Cheers,

John.

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

"Brano" wrote in message
ups.com...
Hi everyone,

I am looking to do a loft conversion in my house, but the roof is
supported with trussed rafters. I am looking for some advice on how to
create an alternative support for the roof so i can take take these
out and create some usable space. I have taken a few pictures and made
a drawing of the roof. I can supply measurements of the timber pieces.

thanks for any advice

pictures he

http://branoblogging.blogspot.com/20...-pictures.html


My mate used these guys.
http://www.trussloft.co.uk/
Baz

Hi everyone,

guys firstly thanks for all your advice. Just to confirm some things. I
have checked the headroom and it will still make a nice bedroom the
highest point of the roof is about 3 meters high. One of you was saying
about old houses my house was build in 2005 and you see what it has
instead of roof... It's terrible the way houses are build in UK.

Oh as far as the snow goes there is none here where I live... so no
worries there


As far as the flooring is concerned i have walked about the roof (on
the joints) and they seem fine they are 2x4 my house is also adjoining
another and thats why my roof is basically just a half of a proper
roof. But in the middle between the two houses there are big big beams
that can be used to put the other timber pieces on them.

Does anyone know how to do the calculations of loadings to determine
what timber you need to use?

The idea of building another roof support is what i basically thought i
will need to do I think i would need to add a piece of timer to every
existing one on the ones that hold the roof the only question is how
strong it should be?

and for the people who were talking about that I am not qualified to do
this sort of job and posting adverts on their own companies thanks but
I am no looking for any replies from you guys...

for everyone else thanks for any more advice you can give

Brano wrote:

Oh as far as the snow goes there is none here where I live... so no
worries there

you're not in the uk? Im not aware of any uk location that never gets
snow.


As far as the flooring is concerned i have walked about the roof (on
the joints) and they seem fine

and for the people who were talking about that I am not qualified to do
this sort of job and posting adverts on their own companies thanks but
I am no looking for any replies from you guys...

for everyone else thanks for any more advice you can give

They may be right. If youre going to do it yourself you need to learn
more first.


NT

I'm in Belfast there was no snow that would stay on the roof for the
last 5 years...

Yes that is exactly what I am looking to do here.
thanks

wrote:
Brano wrote:

Oh as far as the snow goes there is none here where I live... so no
worries there

you're not in the uk? Im not aware of any uk location that never gets
snow.


As far as the flooring is concerned i have walked about the roof (on
the joints) and they seem fine

and for the people who were talking about that I am not qualified to do
this sort of job and posting adverts on their own companies thanks but
I am no looking for any replies from you guys...

for everyone else thanks for any more advice you can give

They may be right. If youre going to do it yourself you need to learn
more first.


NT

"Brano" wrote in message
ups.com...
I'm in Belfast there was no snow that would stay on the roof for the
last 5 years...

In that case you need to study this.

http://www.dfpni.gov.uk/index/laws-a...g-regulations/

Jim A

Brano wrote:
I'm in Belfast there was no snow that would stay on the roof for the
last 5 years...

do you only epect this to last 4 years then??

NT

"Brano" wrote ...


Oh as far as the snow goes there is none here where I live... so no
worries there

All the same, to pass building regulations approval you *must* factor in
snow loading for the one time in 50 years it falls! There's also wind
loading to be allowed for (the highest speed measured in 50 years as a
basis).

As far as the flooring is concerned i have walked about the roof (on
the joints) and they seem fine they are 2x4

Again, building regs mean you'll need much larger floor joists - you walking
around on your own is not the same as the added weight of flooring,
furniture etc

my house is also adjoining
another and thats why my roof is basically just a half of a proper
roof. But in the middle between the two houses there are big big beams
that can be used to put the other timber pieces on them.

So you have a party wall - see below for warnings!

Does anyone know how to do the calculations of loadings to determine
what timber you need to use?


Yes - a structural engineer or architect, whose calculations will be checked
by the building control officer

The idea of building another roof support is what i basically thought i
will need to do I think i would need to add a piece of timer to every
existing one on the ones that hold the roof the only question is how
strong it should be?


See answer above...

If you go ahead and carry out the work without building control (assuming
you're in the UK) the local authority can engage a reputable structural
engineer or architect to prescribe remedies for any deficiencies and
builders to carry out the remedial works, all at your expense. If your works
affect a party wall (and you've stated that it does in your posting), the
Party Wall Act comes into play and you'll need a legal agreement with your
neighbour before commencing work - a solicitor will advise them to engage an
architect or structural engineer, again this will be at your expense so you
may as well do it anyway! The local authority also has powers to demolish an
unsafe structure (at your expense, of course) if they consider it
irrepairable...

If you get it badly wrong, you could find yourself liable for substantial
financial damages to recompense your nrighbours for the collapse of their
roof, as well as ours, possibly damages for injuries to 3rd parties...

Either pay the professionals (who you can sue if things go wrong) or move to
somewhere bigger - either will be financially better than bankruptcy brought
about by legal liabilities and/or possible criminal prosecution!

Dave H.
(The engineer formerly known as Homeless)

"Brano" wrote in message
oups.com...
Hi everyone,

SNIP
and for the people who were talking about that I am not qualified to do
this sort of job and posting adverts on their own companies thanks but
I am no looking for any replies from you guys...

for everyone else thanks for any more advice you can give


Brano.
The link I sent you was sent in good faith.
I hope you took the time to take a look.
As I had taken the time to reply to your post.
I have nothing to do with the company, apart from "My Mate Used Them"
And they where very good, and there are quite a few good suggestions on the
web site.

See this is how it works, you ask for advice and you get advice.

Baz.

Brano wrote:
Hi everyone,

guys firstly thanks for all your advice. Just to confirm some things.
I have checked the headroom and it will still make a nice bedroom the
highest point of the roof is about 3 meters high. One of you was
saying about old houses my house was build in 2005 and you see what
it has instead of roof... It's terrible the way houses are build in
UK.

Oh as far as the snow goes there is none here where I live... so no
worries there

Yes there is! Very high winds can give the roof an excessive loading at
times and in the UK, YOU WILL get snow at some stage wherever you are!

As far as the flooring is concerned i have walked about the roof (on
the joints) and they seem fine they are 2x4 my house is also adjoining
another and thats why my roof is basically just a half of a proper
roof. But in the middle between the two houses there are big big beams
that can be used to put the other timber pieces on them.

Great just walking on the 4 x 2s, you can do that forever and all you'll get
is cracking of the ceiling below - stick a "dead load" of furniture on
those, plus a couple of fast-asleep bodies plus all the other paraphernalia
of the bedroom and loads increase dramatically with undesirable effects.

Does anyone know how to do the calculations of loadings to determine
what timber you need to use?

For what you are asking, you really don't have the knowledge to carry out
the works and you need to take professional advice - to put it bluntly, you
are risking lives if you muck up!

The idea of building another roof support is what i basically thought
i will need to do I think i would need to add a piece of timer to
every existing one on the ones that hold the roof the only question
is how strong it should be?

Take professional advice please, I have seen a bedroom ceiling bending
nearly a foot in the middle of the room with just floor decking and a train
set in the attic - along with the furniture required to support the train
set.

and for the people who were talking about that I am not qualified to
do this sort of job and posting adverts on their own companies thanks
but I am no looking for any replies from you guys...

Take it from me, I am qualified (and from your questions, you certainly are
not) and in my working career within building maintenance both as a
tradesman and manager, I've seen the real scary results of some of the
'fixes' that have been suggested here (that's I why I am so direct in my
wording) and not just a harbinger of doom and gloom.

Remember the following:

1. Do the conversion *WITHOUT* building reg approval etc, and when you come
to sell the house, you may have quite a surprise at what you will lose
financially.

2. The TDRA roof-truss is structurally designed to make the best use of what
are comparatively short lengths of timber that will support the dead load of
a roof that itself can weigh in excess of 20 tons, plus weather loading.
The ceiling rafters (effectively the bottom of the roof truss) are designed
to carry and disperse the downward loads of the roof and the ceiling plus a
person walking along them for maintenance purposes. Start cutting this
about and/or applying higher than designed loads, then you will have
problems.

3. If, after carrying out the works yourself, something goes wrong, see how
quick your insurance company will invoke the clauses in their small print so
that they will not have to pay - along with the possibilty of you appearing
in the 'dock' in front of the fella with the red robes and funny wig facing
a serious charge!

4. If you have a mortgage, and you carry out the works *WITHOUT* the lenders
knowledge or permission - and they find out, you are literally up the creek
without a paddle, as you are effectively reducing the value of their
invesment - read the small print in your mortgage contract/agreement about
various permissions that are required for virtually all works on a mortaged
property - the can be quite restrictive.

for everyone else thanks for any more advice you can give

Yes, if you really want to do the works yourself -- visit a good structural
engineer, architect or loft conversion specialist and pay them to design
what you want and to carry out all the calculations.

You then apply for the necessary permissions from your local authority and
mortgage lender, then arm yourself with the practical knowledge, tools, a
couple of good mates to give a hand as and when needed and get in with a
good builders merchant to get the best material prices - that way, you can
safely and economically carry out a D-I-Y a loft conversion and add value
to the property - along with the proud feeling of having done a damn good
job!


Best of luck in you efforts Brano.

Brian G

A quick question before we get to the detail:

Do you understand that work of this type needs to be notified to, be
supervised by, and ultimately approved by, the building control
department of the local council?

[note this is notthing to do with planning permission which is a
separate unrelated issue]

[If so were you intending to notify and use the building control
department for this work]



Brano wrote:

guys firstly thanks for all your advice. Just to confirm some things. I
have checked the headroom and it will still make a nice bedroom the
highest point of the roof is about 3 meters high. One of you was saying

Which would suggest plenty of height...

Oh as far as the snow goes there is none here where I live... so no
worries there

You still need to take these things into account even if they are only
rare in frequency.

As far as the flooring is concerned i have walked about the roof (on
the joints) and they seem fine they are 2x4 my house is also adjoining
another and thats why my roof is basically just a half of a proper
roof. But in the middle between the two houses there are big big beams
that can be used to put the other timber pieces on them.

This may be the case, but you will need to prove this via calculation.
This in turn means you need a very good understanding of how the current
loft structure works structurally. Note that changes you make might also
affect the neighbours.

To give you some idea of the work involved in constructing the new floor
you can see what I needed to do with my one he

http://www.internode.co.uk/loft/floor.htm

Does anyone know how to do the calculations of loadings to determine
what timber you need to use?

Yes...

The idea of building another roof support is what i basically thought i
will need to do I think i would need to add a piece of timer to every
existing one on the ones that hold the roof the only question is how
strong it should be?

and for the people who were talking about that I am not qualified to do
this sort of job and posting adverts on their own companies thanks but
I am no looking for any replies from you guys...

As long as you are prepared to learn (and there is plenty you will need
to get to grips with if you want to do the whole job yourself) then you
should be OK. The danger comes if you end up having to make guesses or
failyng that, rejecting good advice because you believe you know better.

for everyone else thanks for any more advice you can give

Have a look around my site link above, see if that helps get started

--
Cheers,

John.

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

On 30 Jun 2006 13:05:11 -0700, a particular chimpanzee named "Brano"
randomly hit the keyboard and produced:

I am looking to do a loft conversion in my house, but the roof is
supported with trussed rafters.

http://branoblogging.blogspot.com/20...-pictures.html

Your section appears to show that the roof is a monopitch. Is that
the case, and if so, is it supported on a load-bearing wall at the
top? If so, then you can support your new rafters (or a dormer) from
this wall to the wallplate. If not, then you would have to install a
steel beam at the ridge.

It can be done, but it is a lot more work than a 'conventional' loft
(as said elsewhere, it virtually involves replacing your roof).
Consult a structural engineer in the first instance to see if it's
feasible. If you decide to go ahead, then get a surveyor or architect
to draw up the plans for Building Regulations. Don't be tempted to
let the engineer do more than draw up the structural details, as IME,
they don't have enough of a grasp on the details of the Building
Regulations to do more than **** the BCO off.
--
Hugo Nebula
"If no-one on the internet wants a piece of this,
just how far from the pack have you strayed?"

I am looking to do a loft conversion in my house, but the roof is
supported with trussed rafters. I am looking for some advice on how to
create an alternative support for the roof so i can take take these
out and create some usable space.

The cheapest method is probably to remove the entire roof and build it again
properly. Trussed systems are simply unsuited to conversion. They are
computer designed to save every cm of wood and only resist the loads used in
design, which did not include several people and furniture.

Modification of the existing would be fiddly, and, in all probability, more
expensive because of the labour cost.

An additional advantage of entirely reroofing is that the roof covering gets
relaid and you get to install breathable membrane felt which lets you
install more effective insulation.

Christian.

Christian McArdle wrote:
I am looking to do a loft conversion in my house, but the roof is
supported with trussed rafters. I am looking for some advice on how to
create an alternative support for the roof so i can take take these
out and create some usable space.

The cheapest method is probably to remove the entire roof and build it again
properly. Trussed systems are simply unsuited to conversion. They are
computer designed to save every cm of wood and only resist the loads used in
design, which did not include several people and furniture.

Modification of the existing would be fiddly, and, in all probability, more
expensive because of the labour cost.

An additional advantage of entirely reroofing is that the roof covering gets
relaid and you get to install breathable membrane felt which lets you
install more effective insulation.

Christian.

I dont know whether in such situations you could stretch to another 2'
of wall height added on, but if you can that will much increase the
usable space up there.

NT