What was the purpose of timber wall plates ? All of the first floor balcony joists in my early 19th C Baptist chapel home rest on a 4”x 4” timber plate built into the solid nine inch external brick walls. This original plate was only made of pine and a few sections have rotted and require replacement. It would seem to be a fundamental part of the structures design and yet it seems destined to fail at some point in its life. Were there no other materials at the time such as iron or steel? Would the brickwork wall itself not have been a sufficient base for the joists if the undersides were packed with slate ?
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Nemesis
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In the early 19th century metal technology wasn't developed to make strong and straight beams - that developed over time in the 19th century.
Cast iron was available and in use but it had its problems - in compression it was OK and hugely strong in the right place (hence its use for supporting columns in industrial buildings) but it has no real flexibility and prone to sudden failure and cracking so would not really have been reliable in this situation.
See Tay Bridge disaster...
http://taybridgedisaster.co.uk/
Steel came much later in the 19th century in use in buildings. Tower Bridge is an early use, those two great mock mediaeval towers in fact are simply clothing for huge steel columns, and steel framing developed for buildings towards the end.
Wrought iron was an interim stage - Phoenix Columns, an American invention, were widely used in the US in the latter part of the 19th century for bridges and buildings, they combined great strength with some flexibility and lightness. Wrought iron was also used for such things as railway train sheds - Newcastle Central was a very early example, and the architect John Dobson claimed to have invented the process of curving the metal. Brunel's Paddington Spans 1, 2 and 3 is another example. When his cast iron supporting columns were seen to be leaning precariously and the roof structure none too safe they were replaced with sectional steel ones in the early 20th century, which were an evolutionary step from Phoenix Columns, which is when Armstrong's Span 4, which is of steel, was added.
In the US remaining examples of Phoenix Columns construction are highly regarded. In this country we have two - one is at Redhill railway station, which is a small section example, and the other used in Sir Horace Jones' General Market building at Smithfield. This is currently under threat of demolition, and is the subject of one of the largest conservation battles in recent years. I am England's greatest living bore on the subject, which is just as well really as someone has to be in order to provide historic context for the inquiry to counter the claims of the developer.
Here's a pic, showing the sectional Phoenix Columns and smaller cast iron ones (the roof trusses are laminated wood):
(Courtesy of SAVE)
Metal additionally was expensive, heavy to transport, and remember we did not have, in the early part of the 19th century, the railway network which developed later. Nor indeed did we have the great metal manufacturing industries either.
So builders used what was to hand - and in most cases this was wood, which can bear heavy loads and if kept dry is not really too prone to disaster.
After all, your wall plate has probably lasted a couple of centuries, which really isn't too bad. I suspect the builders at that time had no reason to consider it would need to.
As for resting joists on the brickwork - it's a lot of load to put on a small section of wall. Use of a timber wall plate spreads that load.
Cast iron was available and in use but it had its problems - in compression it was OK and hugely strong in the right place (hence its use for supporting columns in industrial buildings) but it has no real flexibility and prone to sudden failure and cracking so would not really have been reliable in this situation.
See Tay Bridge disaster...
http://taybridgedisaster.co.uk/
Steel came much later in the 19th century in use in buildings. Tower Bridge is an early use, those two great mock mediaeval towers in fact are simply clothing for huge steel columns, and steel framing developed for buildings towards the end.
Wrought iron was an interim stage - Phoenix Columns, an American invention, were widely used in the US in the latter part of the 19th century for bridges and buildings, they combined great strength with some flexibility and lightness. Wrought iron was also used for such things as railway train sheds - Newcastle Central was a very early example, and the architect John Dobson claimed to have invented the process of curving the metal. Brunel's Paddington Spans 1, 2 and 3 is another example. When his cast iron supporting columns were seen to be leaning precariously and the roof structure none too safe they were replaced with sectional steel ones in the early 20th century, which were an evolutionary step from Phoenix Columns, which is when Armstrong's Span 4, which is of steel, was added.
In the US remaining examples of Phoenix Columns construction are highly regarded. In this country we have two - one is at Redhill railway station, which is a small section example, and the other used in Sir Horace Jones' General Market building at Smithfield. This is currently under threat of demolition, and is the subject of one of the largest conservation battles in recent years. I am England's greatest living bore on the subject, which is just as well really as someone has to be in order to provide historic context for the inquiry to counter the claims of the developer.
Here's a pic, showing the sectional Phoenix Columns and smaller cast iron ones (the roof trusses are laminated wood):
(Courtesy of SAVE)
Metal additionally was expensive, heavy to transport, and remember we did not have, in the early part of the 19th century, the railway network which developed later. Nor indeed did we have the great metal manufacturing industries either.
So builders used what was to hand - and in most cases this was wood, which can bear heavy loads and if kept dry is not really too prone to disaster.
After all, your wall plate has probably lasted a couple of centuries, which really isn't too bad. I suspect the builders at that time had no reason to consider it would need to.
As for resting joists on the brickwork - it's a lot of load to put on a small section of wall. Use of a timber wall plate spreads that load.
Lime
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Yes and makes for a good and easy fixing too.
I agree with Nemesis, no galvanised joist hangers or stainless steel bolts in those days I am afraid, pine was readily available and extremely easy to nail together and is ( in this case was) a good building timber, also lasts quite a few generations . Those builders had no reasons to doubt it.
I am sure that if they had lots of money they woul have chosen oak.
I am sure that if they had lots of money they woul have chosen oak.
Nemesis
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Although sadly there was a fire which destroyed a section of this a couple of years' ago and sourcing the timber to repair is not a simple matter, pine can be a very long lasting material even in wet areas, historic Baltic and other pine having a high resin content.
This is btw Grade II* now:
http://www.imagesofengland.org.uk/search/details.aspx?pid=1&id=430242
This is btw Grade II* now:
http://www.imagesofengland.org.uk/search/details.aspx?pid=1&id=430242
Thanks Nemesis, very interesting. A couple of questions though.
My chapel building was constructed in 1817. With regard to load bearing metal avaliable at that time, I understand that an engineer named Richard Trevithick built a railway traveling nine miles between the iron works at Pen-y-Darron in the town of Merthyr Tydfil, Wales to the bottom of the valley in Abercynnon. What were the rails made of as I understand they supported the load of the locomotive together with 10 tons of iron, 70 men and five extra wagons? a bit more than the brickwork in my chapel I suspect.
I live in a seaside town on the south coast and I know that a lot of heavy material from far and wide was transported into the town by ship or boat e.g. York stone being the main paving material around here and Welsh slate from which the chapel roof was constructed.(they should have thrown a few welsh iron rails on the boat as well) Was there really no better alternative than wood. Also the load on each individual joist must be quite small as they are only 2ft or less apart. Does the keyed in overlapping coursework of the brickwork not spread such a load on its own?
My chapel building was constructed in 1817. With regard to load bearing metal avaliable at that time, I understand that an engineer named Richard Trevithick built a railway traveling nine miles between the iron works at Pen-y-Darron in the town of Merthyr Tydfil, Wales to the bottom of the valley in Abercynnon. What were the rails made of as I understand they supported the load of the locomotive together with 10 tons of iron, 70 men and five extra wagons? a bit more than the brickwork in my chapel I suspect.
I live in a seaside town on the south coast and I know that a lot of heavy material from far and wide was transported into the town by ship or boat e.g. York stone being the main paving material around here and Welsh slate from which the chapel roof was constructed.(they should have thrown a few welsh iron rails on the boat as well) Was there really no better alternative than wood. Also the load on each individual joist must be quite small as they are only 2ft or less apart. Does the keyed in overlapping coursework of the brickwork not spread such a load on its own?
Nemesis
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Trevithick's rail track was cast iron - and not too successful - the recently excavated original one which runs past Stephenson's cottage in Wylam was wood I think.
However, this turned out to be only a short-term success. Whilst the locomotive was undoubtedly superior to the horses in terms of the amount it could haul, the increased loads which were possible and the weight of the locomotive itself put unsustainable stress on the rails. Being made of cast iron, these were brittle, and they cracked under the weight. The owners of the Penydarren tramway brought the experiments to an end, and the tramway returned to horse-drawn trains with smaller loads.
Ultimately, the success of the railways would depend on advances in rail technology - first in new materials (wrought iron, and later steel) and second in different shapes (for instance, rolled iron, with the flange taken off the rails and put on the train wheels).
http://web.ukonline.co.uk/cj.tolley/ctrh-pen.htm
(He was also involved with the early days of refrigeration.)
'Unfortunately, technical difficulties meant Trevithick's locomotive only ever made three journeys. Each time, the seven-ton steam engine broke the cast iron rails, and Samuel Homfray came to the conclusion that Trevithick's invention was unlikely to reduce his transport costs so he decided to abandon the project in 1808. Later that year Trevithick developed a new locomotive he called Catch Me Who Can, which he ran on a circular track in Euston Square2, London, charging a shilling for a ride. Plenty of people were willing, especially since his locomotive reached speeds up to 12 mph, but once again the rails broke and he was forced to bring the enterprise to an end.'
http://www.bbc.co.uk/dna/h2g2/A14113838
Even metal railtracks ran on wooden sleepers until not so long ago. Railway tracks also are in short sections, and metal has to have consideration given to expansion too.
http://www.dartfordarchive.org.uk/technology/engin_trevithick.shtml
Wood was an excellent choice of material for your wall plates - especially given the fact the masonry would be laid with soft lime mortar- it still is in many circumstances, so no reason to not use it. It has lasted nearly 200 years...
http://www.oxforddnb.com/public/themes/92/92727.html
However, this turned out to be only a short-term success. Whilst the locomotive was undoubtedly superior to the horses in terms of the amount it could haul, the increased loads which were possible and the weight of the locomotive itself put unsustainable stress on the rails. Being made of cast iron, these were brittle, and they cracked under the weight. The owners of the Penydarren tramway brought the experiments to an end, and the tramway returned to horse-drawn trains with smaller loads.
Ultimately, the success of the railways would depend on advances in rail technology - first in new materials (wrought iron, and later steel) and second in different shapes (for instance, rolled iron, with the flange taken off the rails and put on the train wheels).
http://web.ukonline.co.uk/cj.tolley/ctrh-pen.htm
(He was also involved with the early days of refrigeration.)
'Unfortunately, technical difficulties meant Trevithick's locomotive only ever made three journeys. Each time, the seven-ton steam engine broke the cast iron rails, and Samuel Homfray came to the conclusion that Trevithick's invention was unlikely to reduce his transport costs so he decided to abandon the project in 1808. Later that year Trevithick developed a new locomotive he called Catch Me Who Can, which he ran on a circular track in Euston Square2, London, charging a shilling for a ride. Plenty of people were willing, especially since his locomotive reached speeds up to 12 mph, but once again the rails broke and he was forced to bring the enterprise to an end.'
http://www.bbc.co.uk/dna/h2g2/A14113838
Even metal railtracks ran on wooden sleepers until not so long ago. Railway tracks also are in short sections, and metal has to have consideration given to expansion too.
http://www.dartfordarchive.org.uk/technology/engin_trevithick.shtml
Wood was an excellent choice of material for your wall plates - especially given the fact the masonry would be laid with soft lime mortar- it still is in many circumstances, so no reason to not use it. It has lasted nearly 200 years...
http://www.oxforddnb.com/public/themes/92/92727.html
I take your point about timber probably being more suitable material in a brick/ lime mortar building, particularly with regard to metals expansion however just a last point on metalwork avaliability and technology during the period just prior to the chapel being built; I note that the oldest iron seaside pier is at Ryde on the isle of Wight. Built by John Kent of Southampton it was started in 1813 and completed in 1814 (three years before the chapel) I believe that the pier was able to carry a railway which I think still exists today.
I do understand that most of the forces on a structure of that kind are directed downwards through the columns, but the horizontal ironwork spanning the columns to support the timber platform above must be spreading a considerable load as are the iron train rails themselves. I admit a lot of these horizontal sections have crossed bracing but not all of them and certainly not the rails. The rail lengths as they were, would probably have been suitable and manageable enough to insert in a wall and allow say half a bricks length between them for expansion and perhaps the soft bricks used in the chapels constuction could have acted as the sleeper.The old iron piers are quite deceiving, they look rusty on the outside but the metal under the rusty skin looks as good as the day it was made. I'm sure that if I was dealing with iron rather than wood there would be no decay problems to deal with.
What did you think on my point about the brickwork being able to spread a load by itself Do you disagree?
I do understand that most of the forces on a structure of that kind are directed downwards through the columns, but the horizontal ironwork spanning the columns to support the timber platform above must be spreading a considerable load as are the iron train rails themselves. I admit a lot of these horizontal sections have crossed bracing but not all of them and certainly not the rails. The rail lengths as they were, would probably have been suitable and manageable enough to insert in a wall and allow say half a bricks length between them for expansion and perhaps the soft bricks used in the chapels constuction could have acted as the sleeper.The old iron piers are quite deceiving, they look rusty on the outside but the metal under the rusty skin looks as good as the day it was made. I'm sure that if I was dealing with iron rather than wood there would be no decay problems to deal with.
What did you think on my point about the brickwork being able to spread a load by itself Do you disagree?
Nemesis
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I'm not a building engineer so I can't say. I think it was possibly deemed safer to spread the load across a wall plate however. It possibly served the purpose of tying the wall slightly also. Spread from a heavy slate roof can cause bowing out of walls.
I think that most builders at that time would use what was cheapest and easiest and traditional - after all, building a chapel wouldn't really require experimental building techniques.
Cast iron was used on occasions as support in buildings, alongside wood, for example the cantilevered staircase at Barlaston was found to incorporate cast iron in its structure, only discovered as it was so badly damaged by neglect it had to be rebuilt, but this was in very short sections.
http://www.simonjones.co.uk/meanwhile/extras/pictures/images/barlastonhall.html
http://www.savebritainsheritage.org/barlaston.htm
Trusses developed experimentally through the 19th century too. Cast iron can be resistant to rust, if it's thick enough, but wrought iron even more so - and was used for piers also.
Here's a more detailed history of Ryde pier, which was originally wood and developed over the course of the 19th century:
http://www.theheritagetrail.co.uk/piers/ryde%20pier.htm
http://www.shalfiow.demon.co.uk/Rydepier.htm
http://www.imagesofengland.org.uk/search/details.aspx?pid=1&id=417474
But - as I said - building your chapel possibly wasn't deemed an experiment or a major technical feat - wood had served well for hundreds of years for building with, and if kept dry then it lasts. As indeed yours has.
I think that most builders at that time would use what was cheapest and easiest and traditional - after all, building a chapel wouldn't really require experimental building techniques.
Cast iron was used on occasions as support in buildings, alongside wood, for example the cantilevered staircase at Barlaston was found to incorporate cast iron in its structure, only discovered as it was so badly damaged by neglect it had to be rebuilt, but this was in very short sections.
http://www.simonjones.co.uk/meanwhile/extras/pictures/images/barlastonhall.html
http://www.savebritainsheritage.org/barlaston.htm
Trusses developed experimentally through the 19th century too. Cast iron can be resistant to rust, if it's thick enough, but wrought iron even more so - and was used for piers also.
Here's a more detailed history of Ryde pier, which was originally wood and developed over the course of the 19th century:
http://www.theheritagetrail.co.uk/piers/ryde%20pier.htm
http://www.shalfiow.demon.co.uk/Rydepier.htm
http://www.imagesofengland.org.uk/search/details.aspx?pid=1&id=417474
But - as I said - building your chapel possibly wasn't deemed an experiment or a major technical feat - wood had served well for hundreds of years for building with, and if kept dry then it lasts. As indeed yours has.
Brickwork is more than capable to absorb load spread without the assistance of wall plates or steel girders, it basically depends in which direction the presures are applied. A perpendicular pressure acting on a wall is totally different than an orizontal pressure, the latter can be devastating even to a substantially built wall.
The reality is Michael that with our hindsight and technology available is quite easy to " pick holes" in our predecessors methods of construction, I tend to fall in the same trap at times but soon realise that if we take mass produced steel, cement, nail guns, power tools, upvc and other plastic products out of the equation we would be up to our chin in the shite.
The reality is Michael that with our hindsight and technology available is quite easy to " pick holes" in our predecessors methods of construction, I tend to fall in the same trap at times but soon realise that if we take mass produced steel, cement, nail guns, power tools, upvc and other plastic products out of the equation we would be up to our chin in the shite.
Nemesis
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And I doubt that many of today's mass produced buildings will stand two hundred years either!
We also forget that changes in building design and techniques spread very slowly - there wasn't the internet...
It's possibly a hangover from older traditional building techniques:
http://www.bedesworld.co.uk/academic-buildings-thirlings-reconstruction.php
We also forget that changes in building design and techniques spread very slowly - there wasn't the internet...
It's possibly a hangover from older traditional building techniques:
http://www.bedesworld.co.uk/academic-buildings-thirlings-reconstruction.php
Lime
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michael said:
you're not the antique dealer who tried to sell me a georgian letter box are you?
I didn't think railways were around then.
> Was there really no better alternative than wood.
Possibly this is the wrong question. If you asked was there really nothing else satisfactory but cheaper, the answer would be no, hence wood it was.
Bear in mind the early 1800s was a time of far lower material standards than today, and there were a lot less people and a lot more wood about.
NT
Possibly this is the wrong question. If you asked was there really nothing else satisfactory but cheaper, the answer would be no, hence wood it was.
Bear in mind the early 1800s was a time of far lower material standards than today, and there were a lot less people and a lot more wood about.
NT
Nemesis
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Plus - cast iron wasn't really a suitable proven alternative at that time!
Nemesis
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Lime -
Read the links!
http://www.trackoff.org/history.html
Railways have been around a considerable time, even though at first not steam hauled.
The Causey Arch still stands.
http://www.afundit.co.uk/causey1.htm
http://www.tanfield-railway.co.uk/cms/
'A Brief History
The Railways original purpose was the movement of coal from nearby collieries to ships on the River Tyne.
The oldest part, c1647, was the Lobley Hill section, it had over 300 years of coal traffic when closed in 1964. The surviving 1725 Sunniside to Causey section is now the World's Oldest Working Railway and the Causey to East Tanfield section dates from 1839.-
One of the most significant dates in railway history is 21 February 1804. It was on this date that the Cornishman Richard Trevithick ran the first steam-hauled railway train which went any significant distance. This event took place in south Wales, with the train running between the villages of Penydarren and Abercynon.
http://web.ukonline.co.uk/cj.tolley/ctrh-pen.htm
'Ultimately, the success of the railways would depend on advances in rail technology - first in new materials (wrought iron, and later steel) and second in different shapes (for instance, rolled iron, with the flange taken off the rails and put on the train wheels).
Penydarren was in many ways the start of the story, but the later chapters would be written elsewhere.'
Read the links!
http://www.trackoff.org/history.html
Railways have been around a considerable time, even though at first not steam hauled.
The Causey Arch still stands.
http://www.afundit.co.uk/causey1.htm
http://www.tanfield-railway.co.uk/cms/
'A Brief History
The Railways original purpose was the movement of coal from nearby collieries to ships on the River Tyne.
The oldest part, c1647, was the Lobley Hill section, it had over 300 years of coal traffic when closed in 1964. The surviving 1725 Sunniside to Causey section is now the World's Oldest Working Railway and the Causey to East Tanfield section dates from 1839.-
One of the most significant dates in railway history is 21 February 1804. It was on this date that the Cornishman Richard Trevithick ran the first steam-hauled railway train which went any significant distance. This event took place in south Wales, with the train running between the villages of Penydarren and Abercynon.
http://web.ukonline.co.uk/cj.tolley/ctrh-pen.htm
'Ultimately, the success of the railways would depend on advances in rail technology - first in new materials (wrought iron, and later steel) and second in different shapes (for instance, rolled iron, with the flange taken off the rails and put on the train wheels).
Penydarren was in many ways the start of the story, but the later chapters would be written elsewhere.'
Lime
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Thank you Nemesis.
Thanks everybody. Back to replacing my rotten sections of wall plate I Guess.
Middi - If the wall can take the load by itself, wouldn't it be better just to lime mortar the joists directly into the wall itself. Leaving out the plate and replacing with brick would be one less bit of timber to worry about. Alternatively could I leave out the wooden plate, brick it all in(with lime of course) and use modern joist hangers?
Middi - If the wall can take the load by itself, wouldn't it be better just to lime mortar the joists directly into the wall itself. Leaving out the plate and replacing with brick would be one less bit of timber to worry about. Alternatively could I leave out the wooden plate, brick it all in(with lime of course) and use modern joist hangers?
Nemesis
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As this is a listed and historic building, would it not be better to conserve what is there and only repair like for like? That way the historic construction method would remain for future information. After all, it has lasted two centuries.
Like for like repair, in moderation, requires no LBC. Anything else may well require it. And before trying anything else I'd get some expert opinion on your particular building.
Like for like repair, in moderation, requires no LBC. Anything else may well require it. And before trying anything else I'd get some expert opinion on your particular building.
Thanks Nemisis. I agree with you really. The historical integrity of the building and its construction is important to me. I’m really just playing devils advocate to try and understand the logic of the builders back then. Incidentally the building has a gabled frontage which appears to be a late addition (probably about 1875-1880) presumably added when the parishioners had a bit more money. This has a cement stucco render based on classical designs (imitation blocks and arches). I know you said that building a chapel wouldn’t really require experimental building techniques but wasn’t cement a bit “new wave” and experimental at that time. I only discovered that this was an addition/extension by removing a few timber wall panels and floor boards to follow the timber plate along the wall. The new (Victorian) full height frontage extends back into the chapel about eight feet creating an entrance lobby and a new balcony level above. The plate does not extend through this part of the building. What is surprising though is that this extension is not keyed into the original Georgian building. The new brickwork just finishes flush against the old. Any thoughts on this?