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UK diy (uk.d-i-y) For the discussion of all topics related to diy (do-it-yourself) in the UK. All levels of experience and proficency are welcome to join in to ask questions or offer solutions. |
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Beam Calculation
Hi There
As a strict DIYer i would like to calculate the size of beam required to support a wall, when I make a 2m wide opening in a wall. I am an engineer, but have been working in science for years, so don't know where to start! Can anyone offer any help or advice? Thanks Andrew |
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Andrew Barnes wrote:
Hi There As a strict DIYer i would like to calculate the size of beam required to support a wall, when I make a 2m wide opening in a wall. I am an engineer, but have been working in science for years, so don't know where to start! Can anyone offer any help or advice? Aye - Tony Bryer will be along in a while, but until he's here I'll plug his allegedly excellent SuperBeam program, which you can get a fully-functional print-disabled version of at http://www.sda.co.uk/sbwdemo.htm More design factors than you'd ever considered ;-) For such a relatively tiny gap, you'll prolly find a simple off-the-shelf part at your local Jewsons which is more than adequate. But that's just me handwaving... |
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"Andrew Barnes" wrote in message ... Hi There As a strict DIYer i would like to calculate the size of beam required to support a wall, when I make a 2m wide opening in a wall. I am an engineer, but have been working in science for years, so don't know where to start! Can anyone offer any help or advice? Thanks Andrew Use a wooden "I" beam, not over engineered steel. See: http://www.masonite-beams.se They will do the calcs for you. |
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In article , Imm wrote:
Use a wooden "I" beam, not over engineered steel. See: http://www.masonite-beams.se I quite agree on not using an over-engineered steel. But, by definition, the correctly chosen section in any particular location will not be over-engineered. I suspect that the OP will find that a 127 x 76 UB, 13kg/m is quite adequate but would advise him to get the calcs to confirm this from someone who is qualified (small 'q') to do so. As to using a wooden I-beam I could not find any span/load tables on the above site but generally would not advocate supporting masonry walls off timber, even though this was done in past times. -- Tony Bryer SDA UK 'Software to build on' http://www.sda.co.uk Free SEDBUK boiler database browser http://www.sda.co.uk/qsedbuk.htm |
#5
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"Tony Bryer" wrote in message ... In article , Imm wrote: Use a wooden "I" beam, not over engineered steel. See: http://www.masonite-beams.se I quite agree on not using an over-engineered steel. But, by definition, the correctly chosen section in any particular location will not be over-engineered. I suspect that the OP will find that a 127 x 76 UB, 13kg/m is quite adequate but would advise him to get the calcs to confirm this from someone who is qualified (small 'q') to do so. As to using a wooden I-beam I could not find any span/load tables on the above site but generally would not advocate supporting masonry walls off timber, even though this was done in past times. In the USA it is common to support brick walls with TJIs. |
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In article , Imm wrote:
In the USA it is common to support brick walls with TJIs. It's a fundamentally unsound idea. TJI beams have got next to no lateral stability. This is not a problem with floors because the diaphragm effect of the floor deck keeps them straight and upright. If you put a beam under a wall where does the lateral support come from? In addition the OP wants to take out a wall at ground floor level and support the wall over with a beam taking ? 2-3 tons which means that at either end there will be an upward reaction of one ton or more on the bottom flange of the beam. There's no way any checking engineer would let you do this on a ply web beam without designed stiffeners. If you can direct us to some span/load tables we might just see what would be needed. -- Tony Bryer SDA UK 'Software to build on' http://www.sda.co.uk Free SEDBUK boiler database browser http://www.sda.co.uk/qsedbuk.htm |
#7
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"Tony Bryer" wrote in message
... In article , Imm wrote: In the USA it is common to support brick walls with TJIs. It's a fundamentally unsound idea. TJI beams have got next to no lateral stability. This is not a problem with floors because the diaphragm effect of the floor deck keeps them straight and upright. If you put a beam under a wall where does the lateral support come from? In addition the OP wants to take out a wall at ground floor level and support the wall over with a beam taking ? 2-3 tons which means that at either end there will be an upward reaction of one ton or more on the bottom flange of the beam. There's no way any checking engineer would let you do this on a ply web beam without designed stiffeners. If you can direct us to some span/load tables we might just see what would be needed. -- Tony Bryer SDA UK 'Software to build on' http://www.sda.co.uk Free SEDBUK boiler database browser http://www.sda.co.uk/qsedbuk.htm Although I agree that use of such a beam is a bad idea, it is interesting to note the many houses built up to the mid 60's with first floor walls built off a single or doubled timber joist. Walls built off timber from new would settle naturally, but its a different matter when retrospectively fitting a timber support in situations like this. dg |
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"Tony Bryer" wrote in message ... but generally would not advocate supporting masonry walls off timber, even though this was done in past times. Why on earth not ? In most old houses it is the stone lintels that fail, not the wooden ones. The only time wooden ones fail is when there is an unfixed source of damp causing decay. Our house has bits up to 400 years old and a good mixture of oak, stone and modern lintels in the extension, and I bet I know which bits will still be intact in another couple of hundred years. |
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"G&M" wrote in message
... "Tony Bryer" wrote in message ... but generally would not advocate supporting masonry walls off timber, even though this was done in past times. Why on earth not ? In most old houses it is the stone lintels that fail, not the wooden ones. The only time wooden ones fail is when there is an unfixed source of damp causing decay. Our house has bits up to 400 years old and a good mixture of oak, stone and modern lintels in the extension, and I bet I know which bits will still be intact in another couple of hundred years. Well the main problem is progressive and seasonal movement, which may not only play havoc with the decorations of a modern house, but may not be suitable to other materials in the structure which don't cope to well with such movement. dg |
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"dg" wrote in message .. . "G&M" wrote in message ... "Tony Bryer" wrote in message ... but generally would not advocate supporting masonry walls off timber, even though this was done in past times. Why on earth not ? In most old houses it is the stone lintels that fail, not the wooden ones. The only time wooden ones fail is when there is an unfixed source of damp causing decay. Our house has bits up to 400 years old and a good mixture of oak, stone and modern lintels in the extension, and I bet I know which bits will still be intact in another couple of hundred years. Well the main problem is progressive and seasonal movement, which may not only play havoc with the decorations of a modern house, but may not be suitable to other materials in the structure which don't cope to well with such movement. Use lime mortar (as Grand Designs did tonight) and such problems go away. |
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Andrew Barnes wrote:
As a strict DIYer i would like to calculate the size of beam required to support a wall, when I make a 2m wide opening in a wall. Knowing what load is going to be supported by said beam would be one of your prerequisites. Is this a load bearing wall? What is is made out of? -- Cheers, John. /================================================== ===============\ | Internode Ltd - http://www.internode.co.uk | |-----------------------------------------------------------------| | John Rumm - john(at)internode(dot)co(dot)uk | \================================================= ================/ |
#12
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Knowing what load is going to be supported by said beam would be one of your prerequisites. Is this a load bearing wall? What is is made out of? It is a solid brick wall (single thickness) supporting a similarly sized wall above. The joists upstairs run parallel to it, as do those in the loft, so I assume there is no load from the floors on it? The wall is between my kitchen and dining room, I wish to make a kitchen-diner. The calcs need to satisfy a building officer! Thanks Andrew |
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In article ,
Andrew Barnes wrote: It is a solid brick wall (single thickness) supporting a similarly sized wall above. The joists upstairs run parallel to it, as do those in the loft, so I assume there is no load from the floors on it? The wall is between my kitchen and dining room, I wish to make a kitchen-diner. I'm willing to bet anything you can buy of that length (2m) will be fine. The calcs need to satisfy a building officer! But my bet won't. ;-) -- *Real women don't have hot flashes, they have power surges. Dave Plowman London SW To e-mail, change noise into sound. |
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Andrew Barnes wrote:
Knowing what load is going to be supported by said beam would be one of your prerequisites. Is this a load bearing wall? What is is made out of? It is a solid brick wall (single thickness) supporting a similarly sized wall above. The joists upstairs run parallel to it, as do those in the loft, so I assume there is no load from the floors on it? The wall is between my kitchen and dining room, I wish to make a kitchen-diner. The calcs need to satisfy a building officer! In that case just get a structural engineering firm to do the calcs. They will be believed by the BCO and have professional indemnity insurance if it falls down. Thanks Andrew |
#15
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On Wed, 15 Sep 2004 08:10:59 +0100, a particular chimpanzee named
"Andrew Barnes" randomly hit the keyboard and produced: The calcs need to satisfy a building officer! Are you sure? Has he asked you for calculations, or just to let him know what beam you intend to put in? IME, for a 2m opening, if you were to specify a reasonably-sized beam (i.e., a 178 x 102 UB) then it's unlikely that the BCO wouldn't accept this without calculations. If necessary you could try a box lintel from Catnic, who I understand will provide calculations for you. -- Hugo Nebula 'What you have to ask yourself is, "if no-one on the internet wants a piece of this, just how far from the pack have you strayed?"' |
#16
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"Hugo Nebula" abuse@localhost wrote in message ... On Wed, 15 Sep 2004 08:10:59 +0100, a particular chimpanzee named "Andrew Barnes" randomly hit the keyboard and produced: The calcs need to satisfy a building officer! Are you sure? Has he asked you for calculations, or just to let him know what beam you intend to put in? IME, for a 2m opening, if you were to specify a reasonably-sized beam (i.e., a 178 x 102 UB) then it's unlikely that the BCO wouldn't accept this without calculations. Mine wanted calculations for a 80 cm opening over a doorway (2 standard 100*65 lintels) |
#17
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On Fri, 24 Sep 2004 21:24:59 +0100, a particular chimpanzee named
"G&M" randomly hit the keyboard and produced: Mine wanted calculations for a 80 cm opening over a doorway (2 standard 100*65 lintels) With point loads on them or less than three courses of masonry over them, perhaps? Pre-stressed lintels require the composite effect of the masonry over them to work satisfactorily. Perhaps asking for calcs was a way of proving to someone who argues every point that they won't work. Or maybe you've just ****ed him off something rotten. -- Hugo Nebula 'What you have to ask yourself is, "if no-one on the internet wants a piece of this, just how far from the pack have you strayed?"' |
#18
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"Andrew Barnes" wrote in message
... Hi There As a strict DIYer i would like to calculate the size of beam required to support a wall, when I make a 2m wide opening in a wall. I am an engineer, but have been working in science for years, so don't know where to start! Can anyone offer any help or advice? Thanks Andrew There are various examples to be found by a quick Google. Try BS 5950 But a good general building reference book, which has some basic worked examples is The Building Construction Handbook, by Chudley and Greeno. Its about £15 and well worth it First you need to know the load that a beam of a given section can carry, then work out the load that it will be supporting. Once you have the formula, steel section tables are available from Corus, and another Google on ' weights of building materials ' will get you the info to work out the loading. I don't know if the Superbeam program already mentioned is available as a trial. But its the lazy option if you want it ! dg |
#19
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"dg" wrote in message k... "Andrew Barnes" wrote in message ... Hi There As a strict DIYer i would like to calculate the size of beam required to support a wall, when I make a 2m wide opening in a wall. I am an engineer, but have been working in science for years, so don't know where to start! Can anyone offer any help or advice? Thanks Andrew There are various examples to be found by a quick Google. Try BS 5950 But a good general building reference book, which has some basic worked examples is The Building Construction Handbook, by Chudley and Greeno. Its about £15 and well worth it First you need to know the load that a beam of a given section can carry, then work out the load that it will be supporting. Once you have the formula, steel section tables are available from Corus, and another Google on ' weights of building materials ' will get you the info to work out the loading. Steel? get real a TJI "I" beam will do for most instances. |
#20
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"IMM" wrote in message ... "dg" wrote in message k... "Andrew Barnes" wrote in message ... Hi There As a strict DIYer i would like to calculate the size of beam required to support a wall, when I make a 2m wide opening in a wall. I am an engineer, but have been working in science for years, so don't know where to start! Can anyone offer any help or advice? Thanks Andrew There are various examples to be found by a quick Google. Try BS 5950 But a good general building reference book, which has some basic worked examples is The Building Construction Handbook, by Chudley and Greeno. Its about £15 and well worth it First you need to know the load that a beam of a given section can carry, then work out the load that it will be supporting. Once you have the formula, steel section tables are available from Corus, and another on ' weights of building materials ' will get you the info to work out the loading. Steel? get real a TJI "I" beam will do for most instances. In the real world, price is always a consideration. Not sure what the price of a 2m Trus Joist is, but a 14' 6"x4" steel beam cost me £35 about 2 years ago. Cheers Clive |
#21
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"Andrew Barnes" wrote in message ... Hi There As a strict DIYer i would like to calculate the size of beam required to support a wall, when I make a 2m wide opening in a wall. I am an engineer, but have been working in science for years, so don't know where to start! Can anyone offer any help or advice? This is just an anecdote relating to the above and is not meant to be smart: I heard of an engineer whose first job was for the Irish Telephone company in the early 1980s and his first assignment was to put a generator up on a "beam". He got the weight of the generator and calculated load factors and stuff by looking up some big tables for different materials and doing some calculations. Then he went to put the beam up. When he tried to find beams of certains sizes and/or materials, his choice was severely limited. In the end he used the biggest beam he could find. I suspect you will end up doing something similar (or biggest beam that is cheap and manageable)? Des Thanks Andrew |
#22
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Des Higgins wrote:
"Andrew Barnes" wrote in message ... Hi There As a strict DIYer i would like to calculate the size of beam required to support a wall, when I make a 2m wide opening in a wall. I am an engineer, but have been working in science for years, so don't know where to start! Can anyone offer any help or advice? This is just an anecdote relating to the above and is not meant to be smart: I heard of an engineer whose first job was for the Irish Telephone company in the early 1980s and his first assignment was to put a generator up on a "beam". He got the weight of the generator and calculated load factors and stuff by looking up some big tables for different materials and doing some calculations. Then he went to put the beam up. When he tried to find beams of certains sizes and/or materials, his choice was severely limited. In the end he used the biggest beam he could find. I suspect you will end up doing something similar (or biggest beam that is cheap and manageable)? Indeed. In the end, 'big enough' is all it has to be. 'Too big' is when it won't fit... The steel cost is not huge. Just get an I beam that comfortably fits in, and use that. I'd say a 6x3 I beam is more than man enough. Des Thanks Andrew |
#23
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In article ,
Des Higgins wrote: I suspect you will end up doing something similar (or biggest beam that is cheap and manageable)? I removed a stud but load bearing wall between kitchen and scullery. About 4 metres wide. BO was involved because of other works, and wanted calculations. Which I got. Smallest RSJ was fine, not surprisingly. -- *You are validating my inherent mistrust of strangers Dave Plowman London SW To e-mail, change noise into sound. |
#24
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Des Higgins wrote:
I suspect you will end up doing something similar (or biggest beam that is cheap and manageable)? To be fair, some of the steel fabricators are very flexible these days. You can order pretty much exactly what you need. -- Cheers, John. /================================================== ===============\ | Internode Ltd - http://www.internode.co.uk | |-----------------------------------------------------------------| | John Rumm - john(at)internode(dot)co(dot)uk | \================================================= ================/ |
#25
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"John Rumm" wrote in message
... Des Higgins wrote: I suspect you will end up doing something similar (or biggest beam that is cheap and manageable)? To be fair, some of the steel fabricators are very flexible these days. You can order pretty much exactly what you need. -- Cheers, John. Our local steel suppliers will do the calcs, and select a suitable beam for you if you ask nicely dg |
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I had some advice from the group recently on getting a beam. The
structural engineers I contacted wouldn't get out of bed for less than =A3250! I downloaded the SDA product. which worked a treat to calculate the beam I needed. Tim dg wrote: "Tony Bryer" wrote in message ... In article , Imm wrote: In the USA it is common to support brick walls with TJIs. It's a fundamentally unsound idea. TJI beams have got next to no lateral stability. This is not a problem with floors because the diaphragm effect of the floor deck keeps them straight and upright. If you put a beam under a wall where does the lateral support come from? In addition the OP wants to take out a wall at ground floor level and support the wall over with a beam taking ? 2-3 tons which means that at either end there will be an upward reaction of one ton or more on the bottom flange of the beam. There's no way any checking engineer would let you do this on a ply web beam without designed stiffeners. If you can direct us to some span/load tables we might just see what would be needed. -- Tony Bryer SDA UK 'Software to build on' http://www.sda.co.uk Free SEDBUK boiler database browser http://www.sda.co.uk/qsedbuk.htm Although I agree that use of such a beam is a bad idea, it is interesting to note the many houses built up to the mid 60's with first floor walls built off a single or doubled timber joist. Walls built off timber from new would settle naturally, but its a different matter when retrospectively fitting a timber support in situations like this. =20 dg |
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