Great British Builders

Download Subtitles

Transcript

0:00:02 > 0:00:04Can you manage? ..Oh, wonderful!

0:00:04 > 0:00:10In the olden days when they built these things, they always had a grand party on top with a brass band,

0:00:10 > 0:00:15when really this is best we can do, the old gramophone and the champagne.

0:00:15 > 0:00:18It's a bit sad really because,

0:00:18 > 0:00:22you know, I've knocked lots and lots of these things down

0:00:22 > 0:00:28and this really is the last one to be built in Bolton, hopefully, you know.

0:00:28 > 0:00:30And long may it stand.

0:00:32 > 0:00:35May it have many years of happy smoking.

0:00:59 > 0:01:05Fred Dibnah's work as a steeplejack involved a lot of restoration and repair work on great mill chimneys.

0:01:05 > 0:01:07It gave him real, first-hand knowledge

0:01:07 > 0:01:12of how huge structures like this had been built in the first place.

0:01:12 > 0:01:14By the middle of the 19th century,

0:01:14 > 0:01:21we were constructing some magnificent spinning mills with beautiful chimney stacks like the one behind me.

0:01:21 > 0:01:26This thing here is India Mill in a place called Darwen near Blackburn.

0:01:26 > 0:01:34It were constructed in 1875 and of course when it were first built it were even more ornate than it is now.

0:01:34 > 0:01:39It had loads of beautiful iron work round top which were removed in 1936, I think.

0:01:39 > 0:01:43Really, I think the man who designed it must have been to Venice,

0:01:43 > 0:01:48you know, because there's a tower there that looks almost identical.

0:01:48 > 0:01:52It would all be built from the inside off a platform in the middle,

0:01:52 > 0:01:58and as the walls went up the platform would be moved at six-foot centres up the middle.

0:01:58 > 0:02:04But at the top, the great stones, they weren't allowed to have a steam engine, a steam winch to pull them up

0:02:04 > 0:02:09because some of them were five ton maybe, a piece, and of course the overhang, you know.

0:02:09 > 0:02:13The way they kept them in position while they got more weight on top

0:02:13 > 0:02:16were to put great vertical tie rods down the middle,

0:02:16 > 0:02:22anchored into the brick work below so they couldn't fall off and then they built a bit more on, a bit more on.

0:02:22 > 0:02:29You can see how it goes back in, there's quite a few ton above the cantilever coping stones

0:02:29 > 0:02:33or the collar, as you might say, very interesting, you know.

0:02:33 > 0:02:39I wouldn't like to have to try and dismantle it the same way they put it up, you know, pretty difficult.

0:02:39 > 0:02:42And he could unfold a picture

0:02:42 > 0:02:44of how the chimney were constructed.

0:02:44 > 0:02:46I'd say to him, "Look, the chimney's made of

0:02:46 > 0:02:50"massive stone blocks, how they heck would they get the stone blocks up?"

0:02:50 > 0:02:56"Oh, they'd use so and so, they'd use a tripod on the top and it'd be all handraulic action,"

0:02:56 > 0:03:01as he used to call it. Pulling down, guys with plenty of muscles, they'd use a horse and a pulley wheel.

0:03:01 > 0:03:05In later years they'd use a miniature steam engine hauled to the top.

0:03:06 > 0:03:10The spire at Salisbury's Cathedral is the biggest in all of England

0:03:10 > 0:03:13and, of course, being a steeplejack,

0:03:13 > 0:03:17I've always had a great interest in church steeples and church spires.

0:03:17 > 0:03:21The thing is, finally I've come to rest me eyes on it.

0:03:21 > 0:03:25I'm afraid to say it doesn't impress me as much as I thought it would.

0:03:25 > 0:03:30Number one, I always thought it were 500 feet high and its only 404,

0:03:30 > 0:03:33and it doesn't really look as impressive

0:03:33 > 0:03:39as the one I'm presently repairing in Preston which is 100 feet less in height.

0:03:39 > 0:03:42I think it's because the one at Preston is much narrower

0:03:42 > 0:03:48than Salisbury and that gives it this wonderful impression of great height.

0:03:50 > 0:03:53Because he was up there doing the work himself,

0:03:53 > 0:03:59Fred knew what the challenges were that faced the builders of the great cathedrals of the past.

0:04:02 > 0:04:08This is St Margaret's Church at Bodelwyddan near Rhyl in North Wales

0:04:08 > 0:04:11and I've always greatly admired it, you know.

0:04:11 > 0:04:14Number one, they call it "the marble church" because of

0:04:14 > 0:04:20all the different types of marble that have been used in the interior decoration of it, you know.

0:04:20 > 0:04:26Basically, it's same stuff outside, but the bit I really like is the steeple, the spire.

0:04:26 > 0:04:28It's a work of art.

0:04:28 > 0:04:34The man who actually designed it must have known a lot about the material that the thing's made of,

0:04:34 > 0:04:37because he must have known how many pounds per square inch

0:04:37 > 0:04:42them eight corner stones would take or else he were a bit of a gambler.

0:04:42 > 0:04:46And it's a proper built steeple with a curve on the outside.

0:04:46 > 0:04:50If you stand right underneath the shadow of it and look up,

0:04:50 > 0:04:53you can see the distinct barrel shape of it.

0:04:53 > 0:04:59When you come far away, the trick of the eye, or something to do with perspective,

0:04:59 > 0:05:04it disappears and goes perfectly straight and looks like a needle point.

0:05:13 > 0:05:17Ever since I passed by here, years and years and years ago,

0:05:17 > 0:05:20I stopped one day and had a look at it, you know, beautiful steeple.

0:05:20 > 0:05:25I always wanted to have a closer look and get inside, like where we are now, you know.

0:05:25 > 0:05:29It's interesting because you can see the eight stones up above

0:05:29 > 0:05:34that takes the weight of the top three-quarters of the steeple.

0:05:34 > 0:05:41The other interesting thing is you can see where they had all the timber in the walls when they built it,

0:05:41 > 0:05:43all the put logs across to put the platforms on

0:05:43 > 0:05:48as the spire progressed in an upwards direction.

0:05:48 > 0:05:52If you look right up to the top, you can see the iron cross tree in the top

0:05:52 > 0:05:57that the great nut and bolt comes through to hold the top on the steeple.

0:05:57 > 0:06:01I think I'll go outside now and have a look round on the veranda.

0:06:01 > 0:06:07It just shows you really, it wasn't just industrial history, he was interested in architecture as well.

0:06:07 > 0:06:11He just loved knowing how things had been constructed

0:06:11 > 0:06:15and he was fascinated with the men that did the work.

0:06:15 > 0:06:19Fred was always a great admirer of the ordinary working man,

0:06:19 > 0:06:23and the skills that they built up in the same way that he did.

0:06:29 > 0:06:34Quite beautiful, i'nt it? You can see there's evidence of

0:06:34 > 0:06:36steeplejacking activity of long ago

0:06:36 > 0:06:40up there in the copper rods in the corner plates.

0:06:40 > 0:06:43Mr Firs from Nottingham.

0:06:48 > 0:06:53These lovely pinnacles on the corners with the slender supports,

0:06:53 > 0:06:59you know, fretworked out and the flying buttresses that join one to the other,

0:06:59 > 0:07:01lovely bit of stonework really.

0:07:01 > 0:07:05The fact that he knew what he was talking about

0:07:05 > 0:07:08and the folks liked Fred for himself

0:07:08 > 0:07:11and they liked the way the programme was put together,

0:07:11 > 0:07:15they were learning how things were done without realising it.

0:07:15 > 0:07:17They didn't realise that they were watching the programme

0:07:17 > 0:07:20to learn how these buildings were being put together.

0:07:20 > 0:07:23They just liked the way Fred explained it.

0:07:23 > 0:07:27At the end of the day, they would go away so much the wiser.

0:07:29 > 0:07:32Fred served his apprenticeship as a joiner and,

0:07:32 > 0:07:34at Stokesay Castle in Shropshire,

0:07:34 > 0:07:36he was able to draw on these skills

0:07:36 > 0:07:41to explain the medieval construction technique of jettying.

0:07:41 > 0:07:43When you get up here on the second floor,

0:07:43 > 0:07:48all the walls are timber framed and filled in with lath and plaster.

0:07:48 > 0:07:52It must have been a very important room for the family, and if you had friends round,

0:07:52 > 0:07:57wonderful views of the countryside out through these lovely windows.

0:07:57 > 0:08:02But you must have felt a bit vulnerable if there were any enemies about.

0:08:02 > 0:08:09I rather think that when this bit was stuck on top of here, you know, they were more peaceful times.

0:08:09 > 0:08:13This timber framing, this window frame that I'm stood in,

0:08:13 > 0:08:18protrudes out as much as four feet over the stone walls down below.

0:08:18 > 0:08:23It's a technique developed in the Middle Ages known as jettying

0:08:23 > 0:08:30and of course this north tower here at Stokesay Castle is one of the earliest examples of it.

0:08:30 > 0:08:34Joists to the beams used to support a floor or the floorboards.

0:08:34 > 0:08:39With this business of jettying, they actually protrude over the wall.

0:08:39 > 0:08:45I'm stood in the area where immediate below me there's the outer stone wall of the tower proper,

0:08:45 > 0:08:50then there's about four feet of the joists protruding out into space,

0:08:50 > 0:08:55but when I stand over here, I'm actually stood on top of the moat.

0:08:55 > 0:08:59There's nothing in-between me and the moat, only these floorboards.

0:08:59 > 0:09:02I could show you better if we went downstairs

0:09:02 > 0:09:08and outside and climbed up the ladder to underneath the jetty.

0:09:12 > 0:09:15Now, really, the idea of the jetting is

0:09:15 > 0:09:20you can get a room maybe as much as eight or nine feet bigger

0:09:20 > 0:09:24than you would inside the actual stone walls.

0:09:24 > 0:09:28With the stone walls being very thick and the timber framing very thin

0:09:28 > 0:09:33with the laths and plaster inserts in-between,

0:09:33 > 0:09:36you can really see why they did it, you know.

0:09:36 > 0:09:43They could gain maybe as much as four or five feet all the way around the room, which is quite a big item.

0:09:43 > 0:09:49Must have been a bit draughty because you can see great quarter-inch gaps

0:09:49 > 0:09:50in the floorboards, you know.

0:09:50 > 0:09:54Had thick carpets down they must have had.

0:09:54 > 0:09:57The joists, the actual floor joists,

0:09:57 > 0:10:01are the ones horizontal, sticking out,

0:10:01 > 0:10:05they go straight across inside from one wall to the other.

0:10:05 > 0:10:08Then there's the stone corbels

0:10:08 > 0:10:14with the vertical props which are braced by these 45-degree members

0:10:14 > 0:10:19which in turn are mortise and tenoned into each end and pegged

0:10:19 > 0:10:24so they give the final overhang a bit of extra support, as you might say.

0:10:24 > 0:10:27I think as Fred developed his TV programmes,

0:10:27 > 0:10:31one of the big changes I saw was from "Here's something interesting"

0:10:31 > 0:10:34to "Here's how you should do it, or how it worked."

0:10:34 > 0:10:38I remember clearly his descriptions of how people built cathedrals

0:10:38 > 0:10:42which I thought I knew about until he was able to explain them.

0:10:42 > 0:10:48I'm sure that got over to a huge number of people who never really thought about it before.

0:10:48 > 0:10:52The thing that distinguishes these great Norman Cathedrals

0:10:52 > 0:10:55from the Saxon buildings they replaced

0:10:55 > 0:10:58is their sheer size and scale.

0:10:58 > 0:11:03Of course, the Normans brought these ideas and building techniques

0:11:03 > 0:11:05all the way from France

0:11:05 > 0:11:09and of course left us with these magnificent pillars and arches.

0:11:11 > 0:11:16Fred takes us to the heart of buildings, he shows us,

0:11:16 > 0:11:19not just the grand scale of places like Ely Cathedral,

0:11:19 > 0:11:23but then he helps us understand how they were constructed,

0:11:23 > 0:11:25how they're still standing today.

0:11:25 > 0:11:31We take so much for granted about our great cathedrals, castles and palaces,

0:11:31 > 0:11:33but he shows us the men and women

0:11:33 > 0:11:39who helped to build them bit by bit to make them beautiful.

0:11:39 > 0:11:44This is a demonstration of building an arch.

0:11:44 > 0:11:48Yeah, the wooden bit in the middle, like this bit down here,

0:11:48 > 0:11:50is what's known as the centring.

0:11:50 > 0:11:57Of course, when the thing's set, we can withdraw these wedges down here

0:11:57 > 0:12:02and hopefully the wood'll come slack and then,

0:12:02 > 0:12:06you know, the arch will stay in position.

0:12:06 > 0:12:08It's...

0:12:08 > 0:12:13I'm very confident that it will stay in position.

0:12:13 > 0:12:16I'm not worried about it at all.

0:12:20 > 0:12:22Even though it's waggling about now!

0:12:31 > 0:12:35We'll come back after dinner and take the middle out

0:12:35 > 0:12:37and hopefully it'll stay up.

0:12:37 > 0:12:40I'm fairly confident, I think it will do.

0:12:40 > 0:12:46I'm not really a bricklayer, you know. I'm only a sort of...

0:12:46 > 0:12:48self-taught mechanic, in a way.

0:12:48 > 0:12:51Right...

0:12:51 > 0:12:55now, that's what all good bricklayers do at brew time.

0:12:55 > 0:12:59I'm off now, we'll come back after lunch and take the middle out.

0:13:03 > 0:13:07This is it, the great moment, we're now going to strike the arch.

0:13:27 > 0:13:29Aye, success!

0:13:32 > 0:13:36I don't know what Mr Brunel would have thought about it

0:13:36 > 0:13:38but I'm quite pleased, yeah.

0:13:41 > 0:13:44It looks terribly fragile in its present state

0:13:44 > 0:13:50but if you imagine it being contained at the bottom and at ten to and ten past on the top,

0:13:50 > 0:13:55the more pressure you put on the thing, the stronger it becomes.

0:13:55 > 0:13:58I'm going to attempt to sit on top of it and see what happens.

0:13:58 > 0:14:03I don't think it'll fall down but you never know.

0:14:03 > 0:14:04Here we go.

0:14:08 > 0:14:11I can't really get high enough up, you know.

0:14:19 > 0:14:21How's that?

0:14:35 > 0:14:39Well, as you can see, that were one arch down at ground level.

0:14:39 > 0:14:43The thing is, basically you get the principle or the idea

0:14:43 > 0:14:47of how they actually built arches from that disaster.

0:14:47 > 0:14:51If I'd used a bit more cement in the mortar, it would have stayed up.

0:14:51 > 0:14:54But how did they go on building summat like this behind me?

0:14:54 > 0:14:59You know, three tiers or arches, and all quite slender, really,

0:14:59 > 0:15:03Must have waited a fair time for the mortar to go off

0:15:03 > 0:15:08before they struck the centring out, not quite like what we did.

0:15:09 > 0:15:13His particular contribution was in conveying and explaining

0:15:13 > 0:15:16in an immediate way how things were put together.

0:15:16 > 0:15:22I've seen several TV programmes on which people have tried to explain the principle of a Gothic vault,

0:15:22 > 0:15:26but Fred's the only person I've seen building one in his back garden.

0:15:26 > 0:15:28That was particularly good.

0:15:28 > 0:15:32There's the other one where he demonstrates with a model crane

0:15:32 > 0:15:35how the lantern of Ely Cathedral is put together.

0:15:36 > 0:15:41This magnificent lantern, which is over 200 feet high

0:15:41 > 0:15:45and weighs 200 tons, made of wood and lead,

0:15:45 > 0:15:49is hanging precariously over this great void.

0:15:49 > 0:15:52This really is my personal idea

0:15:52 > 0:15:56of how they managed to get it up all them years ago.

0:15:56 > 0:16:01To raise up these great bauks of timber, which I think are about 60-odd foot long,

0:16:01 > 0:16:05there'd be maybe 50 or 60 blokes on the end of the rope

0:16:05 > 0:16:07that controlled the set of rope blocks

0:16:07 > 0:16:10that raised the real weight of the thing.

0:16:10 > 0:16:14Of course, as it came up, it'd have other guy ropes on

0:16:14 > 0:16:18and men pulling the bottom out and keeping the top in the right shop.

0:16:18 > 0:16:23When they got it in a position where they could anchor it to the stonework

0:16:23 > 0:16:25the next stage of the game would be

0:16:25 > 0:16:29everybody would be holding onto the ropes

0:16:29 > 0:16:34while some intrepid character crept out onto the stonework

0:16:34 > 0:16:37and shoved in the big iron pin.

0:16:37 > 0:16:40This would have to be repeated

0:16:40 > 0:16:43eight times all the way around, or 16 times really,

0:16:43 > 0:16:45cos there's two for every corner

0:16:45 > 0:16:51and of course the next piece would come up in the same manner with the rope blocks.

0:16:51 > 0:16:55Here again somebody would have to pin it to the masonry.

0:16:55 > 0:17:02Then...with the aid of a couple of planks,

0:17:02 > 0:17:05chucked out on here for somebody to go out on,

0:17:05 > 0:17:09it'd be pretty easy to secure the corner there together.

0:17:09 > 0:17:14So you see how real strong it is. I'm pressing down fairly hard on this corner

0:17:14 > 0:17:16and there's not a lot happening, it's pretty tough.

0:17:16 > 0:17:19So if they did that 16 times all around,

0:17:19 > 0:17:23it would be easy then to lace it up with planks from one to the other

0:17:23 > 0:17:28and then construct what I've called the foundation ring for the lantern proper.

0:17:28 > 0:17:33Once they'd reached that stage, they'd reached the stage of stability

0:17:33 > 0:17:36where they'd realised the thing couldn't collapse.

0:17:36 > 0:17:39Up until then it must have been very precarious

0:17:39 > 0:17:44and they must have been a bit, you know, excited and uptight while they were doing.

0:17:44 > 0:17:46I know if I had to do it, I would.

0:17:46 > 0:17:50I mean, you can't compare it so well with modern steel structures

0:17:50 > 0:17:55cos, you know, you can cantilever out for miles, like the Forth Bridge,

0:17:55 > 0:18:00but things like this, they didn't know whether it were going to start creaking and collapse

0:18:00 > 0:18:04till I reckon they'd got that big octagonal shape ring in.

0:18:04 > 0:18:08It's a matter of looking, and Fred was very good at looking and understanding.

0:18:08 > 0:18:15You've only got to see how he approached the technology

0:18:15 > 0:18:19of the medieval carpenters who put up the octagon at Ely Cathedral

0:18:19 > 0:18:22and quite clearly he's really in there,

0:18:22 > 0:18:25getting into their thought processes,

0:18:25 > 0:18:28understanding how they had put those things together

0:18:28 > 0:18:32and what sort of machines they needed to make it work,

0:18:32 > 0:18:34and how they put a rope here and a rope there,

0:18:34 > 0:18:39and what order they put those great timbers up in, in just the same way

0:18:39 > 0:18:44as he would be understanding how an engineer would assemble a steam engine.

0:18:44 > 0:18:47I think that's a lovely thing to be able to do.

0:18:47 > 0:18:51Really, a simple way to explain it all is like a crossroads.

0:18:51 > 0:18:55If you imagine houses coming up to each corner of the crossroads

0:18:55 > 0:18:59and something shoving on the bottom corners of them,

0:18:59 > 0:19:04you've got to shove a row of houses out the way before the thing can go downwards.

0:19:04 > 0:19:10In a way, down below here we've got the nave and the transepts, which in actual fact is a crossroads

0:19:10 > 0:19:15and of course the main thrust is on the end corners of the walls,

0:19:15 > 0:19:19so you've got to shove out the way the whole length of the cathedral.

0:19:19 > 0:19:23It would never come to that, but that's in theory what it is,

0:19:23 > 0:19:26before this block can actually descend.

0:19:26 > 0:19:29It's all very cleverly done really, you know.

0:19:29 > 0:19:35When you think it's so old and what have you, it's a credit to them how they managed to do it.

0:19:35 > 0:19:38All for the glory of God.

0:19:38 > 0:19:42And he very often said, a thing I liked about him,

0:19:42 > 0:19:44"That's a great credit to them."

0:19:44 > 0:19:46And you felt he really meant it.

0:19:46 > 0:19:52There was somebody who centuries before had created this thing and he was there appreciating it.

0:19:52 > 0:19:56Anyway, Jonathan, tell me which is Cardinal Wolseley's bit?

0:19:56 > 0:20:00From that gable and the gate house to the other gable,

0:20:00 > 0:20:04that's all Wolseley's material, and then Henry VIII added these arms.

0:20:04 > 0:20:06That one's a toilet for 28 people.

0:20:06 > 0:20:11This wonderful, diagonal sort of diamond brick,

0:20:11 > 0:20:15it's quite beautiful, that.

0:20:15 > 0:20:21If you look closely at the Tudor stuff, you see it doesn't quite carry through the whole facade.

0:20:21 > 0:20:26- I've been straining me eyes at it. It's all a bit different, isn't it? - Yes, very irregular.

0:20:26 > 0:20:29- There's no proper symmetry about it, is there?- No.

0:20:29 > 0:20:34This new brickwork in the middle, how come that's nice and pink?

0:20:34 > 0:20:39- Alarm bells ring when you see a completely different colour brick. - A rebuild of some sort.

0:20:39 > 0:20:42It's an 18th-century rebuild and reface of that gatehouse

0:20:42 > 0:20:46because Wolseley built too quickly for his foundations to last long

0:20:46 > 0:20:52and originally that gatehouse had two wings on each side, which made the centre part the lower

0:20:52 > 0:20:56and they were taken down in 1777 after cracks were seen.

0:20:56 > 0:20:58So now it's reversed its original appearance.

0:20:58 > 0:21:01It looks like a podium now, doesn't it?

0:21:01 > 0:21:05Yeah, the chimney stacks, they're summat else, aren't they? Every one different.

0:21:05 > 0:21:09None are Tudor, the ones you see, but they're faithful copies of Tudor designs.

0:21:09 > 0:21:14I wonder how they got...that beautiful twist on them, you know.

0:21:14 > 0:21:17That's an interesting thing, you know.

0:21:17 > 0:21:21I read somewhere about a stick, you know, up the middle.

0:21:21 > 0:21:27I think that's how they built them. A pole in the middle, a template on it and move the template round

0:21:27 > 0:21:30because you only need about two or three types of brick.

0:21:30 > 0:21:33It's economical to get a spiral - just move the next course round.

0:21:33 > 0:21:38Yeah, it's a good way of doing that, it's quite simple and practical, if you think about it.

0:21:38 > 0:21:41And made a wonderful skyline. When all the pinnacles are there,

0:21:41 > 0:21:47all the lead caps on the turrets, it must have been a wonderful view from afar, and with gilding on top of it.

0:21:47 > 0:21:48All painted as well.

0:21:48 > 0:21:53Sometimes, when we stand in front of a great palace like Hampton Court

0:21:53 > 0:21:55it's hard to take it all in.

0:21:55 > 0:22:01We can see it's so complex and it's built up over so many generations, but Fred leads us through it.

0:22:01 > 0:22:07He shows us how each space functions and the people who helped build it

0:22:07 > 0:22:09and then we can understand it and enjoy it more.

0:22:09 > 0:22:14- You're a man who works with your hands, Fred.- Oh, yeah.- How would you make something like that?

0:22:14 > 0:22:17That particular panel, it'll be about...what is it?

0:22:17 > 0:22:2112 inches by maybe 23 inches long or thereabouts.

0:22:21 > 0:22:26It would initially start off as a piece of oak on a bench

0:22:26 > 0:22:32and the guy would cut in vertically down the edge of the panels.

0:22:32 > 0:22:36They must have had a bit of a gauge to know they were at the right depth.

0:22:36 > 0:22:41Same at both ends and then the timber in-between all the folds

0:22:41 > 0:22:46would be done with like concave and convex moulding planes and small grooving planes.

0:22:46 > 0:22:50- So you groove the whole length and that's done in an instant?- Yeah.

0:22:50 > 0:22:54That looks to me as though it could have been done same as masonry

0:22:54 > 0:22:59- with an hammer and chisel, you know, cos it's all a bit up and down. - I see, right.

0:22:59 > 0:23:04That's the sort of effect to get it to look like folded up material.

0:23:04 > 0:23:10I had a friend once, God bless him, he's dead and gone now, but he actually played the fiddle

0:23:10 > 0:23:14in the Halle Orchestra but he were a budding woodworker.

0:23:14 > 0:23:17His favourite timber were oak, and before he died,

0:23:17 > 0:23:20he promised me he'd learn me how to make linen-fold panelling

0:23:20 > 0:23:23and he did all his house with it.

0:23:23 > 0:23:26It was quite magnificent, the doors, panelling and everything.

0:23:26 > 0:23:29It were very effective and looked very nice.

0:23:29 > 0:23:32Aye, this is Henry VIII's bit, is it?

0:23:32 > 0:23:36this hall was rebuilt by Henry VIII on the site of Wolseley's.

0:23:36 > 0:23:40I'm researching that at the moment and it seems almost certain

0:23:40 > 0:23:44that Wolseley's hall was actually longer, bigger by area.

0:23:44 > 0:23:47It's 39 feet wide and 114 feet long

0:23:47 > 0:23:51and this was the great ceremonial entrance room,

0:23:51 > 0:23:53so it's decked with tapestries,

0:23:53 > 0:23:56each costing as much as an armed battleship to make,

0:23:56 > 0:23:58- took about four years. - Blooming heck.

0:23:58 > 0:24:01So it's a show-off room, designed to impress you.

0:24:01 > 0:24:07I mean, this magnificent roof is summat, and I've always thought that they designed that

0:24:07 > 0:24:11because they couldn't get any big lumps of timber really.

0:24:11 > 0:24:17If you think of the size of an oak tree, as compared with later architectural feats

0:24:17 > 0:24:21of big engineering works with 60-foot long beams, you know,

0:24:21 > 0:24:28I mean, there's no bit of wood up there that's more than maybe ten feet or 12 foot long, is there?

0:24:28 > 0:24:32You're limited by the length of trunk a tree can provide for a beam.

0:24:32 > 0:24:36If you imagine spanning 40 feet, you'd need a beam of immense depth.

0:24:36 > 0:24:41I've seen that myself in industrial premises in Lancashire, you know.

0:24:41 > 0:24:46To get across here it would be maybe two feet deep by nine inches thick

0:24:46 > 0:24:53with a queen post and two vertical posts heavily braced up with iron rods to accomplish the same thing.

0:24:53 > 0:24:58And if you imagine the feeling of lightness and space you want to get within this hall,

0:24:58 > 0:25:02if you have beams coming across, you've spoilt it already, I think.

0:25:02 > 0:25:06In Westminster Hall in the 1390s they pioneered this technique,

0:25:06 > 0:25:12using a hammer beam and building it straight out from the wall like a cantilever, so that can support

0:25:12 > 0:25:15a vault just under the central section of the roof.

0:25:15 > 0:25:19So it's a very light construction, like the underside of a ship.

0:25:19 > 0:25:24Yeah, and when it is all bolted together, the weight's basically

0:25:24 > 0:25:28straight down on the walls instead of trying to shove them out.

0:25:28 > 0:25:33It is a very elegant engineering solution, and this is one of the latest cos Westminster was 1390s,

0:25:33 > 0:25:37this was 1530s, so it's quite late on in history.

0:25:37 > 0:25:40Before, they used to build a stone arch across, didn't they?

0:25:40 > 0:25:44- Then, you know, put the timber on top of that.- Sometimes they did.

0:25:44 > 0:25:48They had a variety of timber trusses but most are less elegant than this.

0:25:48 > 0:25:50Oh, I know. This is beautiful.

0:25:50 > 0:25:54Yeah, it's Henry VIII's best piece of building here certainly.

0:25:54 > 0:25:58He would actually show with practical demonstrations

0:25:58 > 0:26:03how timber beams worked, for example, and how it was a very precise art.

0:26:03 > 0:26:06Something which I think people tended not to notice before,

0:26:06 > 0:26:10they tended to look at things and say, "Oh, the ceiling's up there,"

0:26:10 > 0:26:13rather than, "Isn't it clever how that is kept together?"

0:26:13 > 0:26:17I remember, I suppose because I was quite interested in it myself,

0:26:17 > 0:26:20the whole business of hammer beam roofs.

0:26:20 > 0:26:24He actually made a hammer beam joint on one occasion

0:26:24 > 0:26:28and I remember the slight nerves he managed to exhibit,

0:26:28 > 0:26:30I'm sure he wasn't feeling them at the time,

0:26:30 > 0:26:36of hammering in the last pin and saying, "Once this goes in it won't come out," and he proved it.

0:26:36 > 0:26:42He made a very good locking joint and made the point of how these great roofs do hang together.

0:26:42 > 0:26:46In the Middle Ages, the roof construction,

0:26:46 > 0:26:50like hammer beam roofs and crook beam constructions,

0:26:50 > 0:26:55the main joint really in all of it were the mortise and tenon joints,

0:26:55 > 0:26:59which is basically a hole in one block of wood

0:26:59 > 0:27:02and a bit sawn on the end of the other that fits in the hole.

0:27:02 > 0:27:07The tools needed to form such a joint are fairly simple -

0:27:07 > 0:27:09a chisel and a hammer.

0:27:11 > 0:27:17And then of course a saw for sawing the tenon on the end of the beam.

0:27:17 > 0:27:22Then of course it's held together by a dowel or a peg,

0:27:22 > 0:27:26and you drill the hole slightly out of centre,

0:27:26 > 0:27:31so when you put the tenon down the mortise hole and knock the peg through,

0:27:31 > 0:27:36the peg has a pulling effect on the shoulders of the tenon and pulls it all together.

0:27:36 > 0:27:39That's what I'm about to undertake to do now.

0:27:39 > 0:27:43That goes in there, like that,

0:27:43 > 0:27:46and then we've got this beam.

0:27:46 > 0:27:52The hole is slightly out of line so when I knock this wooden peg in here

0:27:52 > 0:27:58it'll have the effect of pulling the tenon down into the mortise hole.

0:27:58 > 0:28:02Of course, once we've knocked it in, we won't be able to get it out, so here goes.

0:28:08 > 0:28:11That feels very good and very tight

0:28:11 > 0:28:14and I think...

0:28:14 > 0:28:16it's solid as a rock.

0:28:19 > 0:28:21No daylight,

0:28:21 > 0:28:23slightly out of square

0:28:23 > 0:28:28but I think it's the fact that that side of the timber's round.

0:28:28 > 0:28:31Of course, on this side it's flush all the way over.

0:28:31 > 0:28:36Even for the Middle Ages, that's a pretty good joint...I think, anyway!

0:28:43 > 0:28:47Subtitles by Red Bee Media Ltd, 2006

0:28:47 > 0:28:51E-mail subtitling@bbc.co.uk