Hello and welcome to today's design and technology lesson.

I'm really glad you've decided to join us for our learning today.

My name's Mrs. Fletcher and I'm here to help and guide you through today's learning.

Now today's lesson is called Wood Functional Properties and it's part of the Cam's Automat Unit.

In the lesson today, we'll get to look in depth at the wonderful material that is wood and we'll get to learn a little bit more about the properties of this material.

So let's have a look at what we'll be learning about today.

We are going to be learning about the two main groups that wood can be categorised into, the hardwoods and the soft woods.

And we're going to be learning about the properties of those different types of woods.

By the end of today's lesson, you'll be able to explain the difference between hardwoods and softwoods and even be able to discuss some of the different types of products that they are used for.

Now as always, there are some key words that will come up in today's lesson that we need to make sure we have an understanding of.

So let's have a look at these together.

So first of all, we've got the word deciduous and that's used to describe trees and shrubs that lose their leaves every year.

So their leaves turn brown in the autumn and they fall from the tree in the winter.

The second word is the word evergreen.

And this is used to describe trees and shrubs that do not lose their leaves so they stay green throughout the seasons.

The word hardwood is used to describe the wood that comes from the trees that lose their leaves in autumn.

So those deciduous trees, a soft wood is wood that comes from trees that keep their leaves all year round.

So those evergreen trees.

And then we've got the word grain.

And this is used to describe the pattern that you can see in wood when it's usually when it's been cut open.

So today's lesson is going to be split into two parts.

First of all, we're going to be learning about the properties of hard wood and soft wood, and then we're going to move on to looking at hardwood and softwood timber products.

So that's what those woods are used to make.

So let's get started with the properties of hardwood and soft wood.

Now, wood is a renewable natural material that means it grows naturally on the earth and it's renewable.

So it grows again, continues to grow so we can use it.

And it's been used throughout history for many different purposes.

From fuel for fires to building homes and furniture and structures like bridges.

There are many more things that wood has been used for.

Can you have a think of any other things that you can think of that have been made from wood in the past or are currently made from wood? Pause the video, have a think, talk to a partner or write down some ideas.

What else has wood been used for? Welcome back.

So what do you think, what has wood been used for in the past are is currently used for? There's lots of other examples.

You could have said something like weapons and tools, toys, transport and even art.

Wood can be grouped into two different types.

So as I've already mentioned, there are the hardwoods and there are the soft woods.

The type of wood depends on the tree that it comes from.

Hardwood timbers usually come from slow growing deciduous trees.

So that's those trees that lose their leaves in the winter.

Some examples of those types of trees are oak, beach, ash, mahogany and walnut.

There's a picture of an oak tree, you may recognise it.

Deciduous trees have broad, that means wide and flat leaves that turn brown and fall in the autumn and in the winter, deciduous trees have a very tight close grain.

So remember the grain was that pattern that you can see inside the wood.

It's very close and very tight, which makes it much harder to cut.

It's a much harder wood.

All types of wood have knots in it.

And knots are those circular patterns that you see on a piece of wood.

And they're formed where branches once grew on that tree.

So it's the part of the wood where a branch used to come out from.

Now, because hardwoods take longer to grow and because they have a very close grain, they are often much stronger and more durable than softwoods.

So they use for things that need to be strong and durable.

The rings here, you might know show the age of a tree because each ring is a stage of growth, it's a new year's worth of growth.

So sometimes people say you can count the rings to see how old a tree is.

And that's kind of true because you can see the stages of growth on a tree.

The slow growth of deciduous trees makes that grain, that pattern really tight and that's what makes that the wood much stronger.

Hard wood trees can take over a hundred years to fully mature into full grown trees and this means it takes much longer to replace them.

So once it's been chopped down, it can take up to a hundred years to replace that tree to make it fully grown.

And that's why this type of wood usually has a higher cost.

So it costs more to buy compared to a soft wood tree which can usually be replaced in 20 to 40 years.

And Alex is given us a really interesting fact there that some hardwood trees can even take up to 250 years to grow.

So you can see why those slow growing trees might cost a little bit more to buy.

Quick check then how long do softwood trees take to grow? So I've just talked about how long it takes hardwood and softwood trees to grow, but how long do the softwood trees take to grow? Was it zero to 20 years? Was it 20 to 40 years? Was it 40 to 60 years or was it more than a hundred years? Pause the video, have a think.

Well done if you said it was 20 to 40 years, so much quicker than those hardwood trees.

Now whilst they are known for their strength and durability, not all hardwoods are actually dense and hard.

Some of them are quite the opposite.

In particular, a wood called balsa.

Now balsa is a very, very light, very soft wood, but it comes from a deciduous tree.

The balsa tree is actually a deciduous tree, but the wood that comes from it is very, very light.

It's often used for things like model making.

And again, Alex is here with another interesting bit of information that he has used this type of wood to make a balsa wood aeroplane with his sister.

And it is typically used for things like that because it's a very light, very easy to cut type of wood.

Now, quick check, true or false, the close grain in most hardwoods is what makes it strong.

Is that true or false? Have a think, pause the video if you need to.

Well done if you said it is true, but why? Why does that close grain make the hardwoods strong? Well it's because the slow growth makes the wood dense, which means tight.

So it's stronger because there's less room for flexibility, less room for the fibres of the wood to move around.

Okay, so let's move on to soft wood timbers now.

So soft softwood timbers usually come from a very small group of fast growing evergreen trees and those trees typically have needles and cones.

And when we get a tree that has needles and cones, they are referred to as coniferous trees.

So specifically, things like pine, cedars, fur trees, large trees and you, you may recognise some of those names.

Needles and cones are what define those types of trees.

So these kind of pine cones and instead of leaves, they have those needles instead.

These types of evergreen trees usually have needles and cones instead of the leaves and they stay green all year round.

So that's the characteristic of this type of tree.

They have a loose grain, so the opposite of those deciduous trees.

So the pattern inside is much more open and that makes it much easier to cut.

Just like the hard wood, they still contain knots because just like the other trees, the branches would've grown on there at one point.

And where they used to grow is where we get those knots in the wood knot can sometimes leave weaknesses in the wood, but that can be true of hardwoods and soft woods because those soft woods have a quick upward growth.

So that means they grow really tall really quickly and they have that grain.

They are often more sustainable.

So sustainable means that we can use them and replace them and keep using and replacing them without completely getting rid of all the supply of that wood.

But it does mean that they are less durable than hardwood.

So that means that they don't last as long, they're not as strong, they don't put up with as much use as a hardwood wood.

So the characteristics of those softwood trees is those long straight trunks because they're growing upwards very quickly and that wider looser pattern inside that grain inside the wood is what characterises those types of trees.

So quick check, which of these trees then would be a soft wood tree.

So think about those characteristics we've just talked about.

Which of these would be a soft wood tree? Pause the video, have a think.

Okay, what did you think? Did you look some clues there? So well done if you said the answer was B.

Because if you remember I said that softwood trees are coniferous, that means that they have needles and cones and the other two trees were trees that you could see there were trees that lose their leaves in the autumn, which is a characteristic of a deciduous tree.

Okay, so those soft wood trees, they're known for their flexibility and their loose grain.

But again, not all softwoods fall into that group.

Not all of them are soft and light.

A yew is a very heavy hard wood, but it comes from a coniferous softwood yew tree.

And traditionally that type of wood was used to make tools and weapons which needed to withstand really heavy use.

So it's a hard wood but it comes from a soft wood tree.

So there are some exceptions to the rule about hardwood and soft woods.

Okay, time for a task.

I would like you to sort the properties of hardwood and softwood into two groups.

Now you can use the template on the next slide on your worksheet, cut out and sort the cards into two groups.

Or alternatively you can write them out on your own pieces of paper or just write them into two columns on a whiteboard or on a piece of paper.

So you're going to think about the types of trees that those woods come from and the characteristics.

So that's how we know what type of wood it is.

So you're going to have a look at the cards on the next slide, pause the video, have a go at sorting them and come back when you are done.

So those words are close grain, broad leaves, slow growing, sustainable, coniferous trees, quick growing, hard, heavy yew wood, deciduous trees, durable, evergreen, loose grain, affordable, expensive, light, soft balsa wood, long straight trunks and wide trunks.

Good luck.

Welcome back, how did you get on? Did you manage to sort them into those two groups? Let's have a look at what we should have in each group.

So in the hardwood group we should have that they have a close grain, that they are expensive compared to a softwood.

They come from the deciduous trees.

They are more durable.

A light soft BOLs of wood is actually an example of a hardwood even though it's light and soft.

It's one of the exceptions to the typical properties of a hardwood.

They have those broad leaves.

So those wide flat leaves, they're slow to grow and they have wider trunks because of that slower growth.

They grow outwards as well as upwards.

So that means in the softwood column we should have had that.

They have a loose grey, they're more affordable, they come from those coniferous trees, those ones with the needles and cones.

They're more sustainable.

A hard heavy yew wood is actually a type of soft wood.

Again, it's one of those exceptions.

They are evergreen, they're quick to grow and they have those long straight trunks.

Because of that quick growth, they grow upwards very quickly, which leaves them with a long straight trunk.

Okay, so time to move on to the next part of the lesson now.

So now we know the difference between those two words.

We can have a look at hardwood and softwood timber products.

So that's looking at what those different types of woods are used for.

So wood that is specifically grown and used for manufacturing.

So that's for making things is referred to as timber.

So when we use the word timber, we're talking about wood that has been cut down, ready to use.

Trees are first fell, which means chopped down to collect the raw material which is the wood.

The logs are then sent to be processed and the timbers are used to make new products.

So it turns from a wood into a timber just by being processed, ready for use.

Quick check then which word is used to describe wood that is to be used to make things? Is it A, resin, B timber or C fibres? Pause the video.

Have a think.

Well done if you said timber.

So timber is the word we use to refer to wood that's been processed ready for use in manufacturing.

Okay, so hardwood timbers are typically used to make products that are decorative, durable and long lasting things like instruments are made from hardwoods, doors and window frames, particularly external ones.

So that's ones that are outside and furniture particularly very decorative furniture.

Softwood timbers though are typically used to make products that are lightweight, cheaper to buy and easier to replace.

So things like internal doors, inside buildings garden sheds and decking and things like that that might be used as flooring.

Softwoods are used to make paper and card products.

So it's actually the type of wood that is used to make paper.

Sometimes paper is made from recycled paper products or things that have already been made, but if it's made from new, it's made from those soft wood fibres.

It's also good for use in the building industry.

So paper made from the pulped soft wood and those long straight trunks are what make them good choices for building materials.

'Cause you want a nice good straight piece of wood if you're building a new house or a roof on a house.

Quick check then, why are external windows and doors, that's the ones on the outside often made from hardwood? Is it because they're more durable in all weathers? Is it because they're easier to cut and shape or is it because they are more affordable? Pause the video, have a think.

Okay, what did you think? Well done if you said they are more durable in all weathers.

That's exactly right.

They are much more durable against the weather that it might come across outside.

So the type of timber that's chosen to make a product depends on the user.

So that's who's going to use that wood product, the functions, that's what we'll want it to do and the affordability.

So how much it's going to cost.

Some products can be made from either hard or soft wood and it wouldn't matter.

Some products can be made from either, for example, this table, we could have a soft wood side table, we could have a hard wood side table, they might look different, they might have different properties but essentially they're doing the same job.

So some products can be made from either woods, it doesn't really matter.

Now Izzy has been looking at some products made from hardwood and softwood timbers and she's been looking at the side table that we've just had a look at there and she's been thinking about those characteristics of the wood and why it was used for that product.

So she's thinking this table's been made from soft wood, it's got a simple design so it's not very decorative so it's quick to produce.

And the loose grain from a soft wood makes it easy to shape.

So because it's very easy to make the parts of that table, it makes it much quicker to make.

So it makes it more affordable because it's quicker to make.

We can make many more of them quickly.

It makes it cheaper for the user to buy.

And because the wood is soft that would make mean it could get scratched or marked more easily.

But because it's got that lower price it could be replaced more easily too.

So that's what Izzy's been thinking about that timberwood, that timber product.

She compared that first product that she's just been looking at there to a similar one made from a different timber.

So this time the hard wood side table she's been looking at and this time she's thinking that this table is made of hardwood, it has a decorative design so it would take more time to produce, which would make it more expensive, it's more durable because hardwood has a much closer grain and that makes the wood stronger but it would be harder to replace because of the cost.

So it would be more expensive and the fact that they would be made in much fewer numbers so there would not be as many of those to replace the ones that you might want to replace.

So she's compared the two different products, the same essentially the same products but made from different woods which mean they will function in a different way and they might appeal to a different type of user.

Quick check then why are those soft woods more affordable? Is it because of they've got those straight trunks? Is it because they're evergreen or is it because they grow quickly? Pause the video, have a think.

Okay, what did you think? Why are softwoods more affordable? Well done if you said it's because they grow quickly.

So because they act quick to replace, quick to grow a new tree, they're much less expensive to buy time for a task now.

So this task is going to be split into four parts.

So I want you to listen and have a look at part one and two, then go away and have a go at answering those parts.

Come back and we'll see what you thought and then we'll have a look at parts three and four after that.

So for part number one, I want you to explain why building materials are often made from soft wood.

So why is that type of wood chosen for building materials? And then I want you to explain why external doors and windows, so those on the outside of a building are often made from hardwood.

So again, I want you to use the properties and characteristics of those types of woods to explain why they are used for those two products.

Have a go at doing that on the worksheet or on a separate piece of paper and come back when you're finished.

Okay, welcome back.

What did you think about those two types of products and the types of woods that are used to make them? So you may have answered something like this.

So for number one, softwood timber is often used in the building trade or for building materials because it provides those long straight planks, it's more affordable to buy and it's easier to cut and shape on the building site because it has a loose grain.

So it's much easier to cut to the size that they need in the moment.

And for part number two, they might have written something like this.

External doors and window frames need to be hard wearing and durable because they're exposed to all types of weather and they provide protection.

It's the close grain of the hardwood that makes it stronger and therefore that's it'd be more suitable for the job of protecting and being hardwearing from the weather.

Well done if you answered something similar to that.

Let's have a look at the next part of our task.

So part three then, and we just have a look at this product.

So this is an outdoor climbing frame and they are often made from hardwood.

Now I want you to have a think.

Can you explain using again the properties of a hardwood, why this wood would be chosen for this type of product? So explain in your own words but using those characteristics and properties of a hardwood.

You can do it on the worksheet or on your own piece of paper.

Pause the video while you do this task and then come back and we'll see what you think.

Okay, welcome back.

So for that task then, what did you think the key reasons why this product is made from hardwood is that it's durable so it can be exposed to all types of weathers.

It's hard wearing, so it's suitable for heavy use, which a climbing frame would get.

It has a close grain which makes it a dense hardwood, so it's less likely to be damaged if it's a very tough hardwood and it'll be long lasting because of that.

So it'll last for years, it'll be available to use for a long time.

So hopefully, you included those properties and characteristics in your explanation And I can have a look at the next part.

So this product is made from softwood.

So this is a delivery pallets and these are used by delivery companies to move products from one place to another.

So you usually see them piled high with boxes of products on top of them and they're used by forklift trucks to lift and put into trucks and then delivered to wherever they're going.

So could you explain then why they might choose a soft wood for this product? Why would a soft wood be better for this type of product? Again, you can write it on the worksheet or have a go in your own piece of paper, pause the video and come back when you finish and we'll see what we think about this product.

Okay, welcome back.

So the delivery pallets are often made from softwood and the key reasons why they're made from softwood is because of the low cost.

So because they need large quantities of these for delivering all over, lots of different companies are using them, they need a lot of them, they need to be low cost, cheap to buy, and softwoods are cheaper to buy.

They need to be lightweight because they don't want to add any weight to the delivery vehicles on top of the products that they are delivering.

And they need to have a loose grain which makes them easier to cut and shape.

So, that means they are quick to produce so they can be produced, lots of them can produce very quickly 'cause they're used every day by lots of different companies.

So being able to produce them quickly makes this type of wood more suitable for that product.

So well done if you included those key points in your description of why a soft water is used for pallets.

So we are at the end of today's lesson and we learned lots about hardwoods and softwood.

So let's have a quick summary of exactly what we have learned today.

So we've learned that hardwoods and softwoods come from different types of trees.

So those hardwoods comes from deciduous trees and those softwoods come from coniferous trees.

Softwoods are usually cheaper to purchase to buy and they're more sustainable because they're quicker to grow.

So because we can replace them much quicker, they don't cost as much as a hardwood.

Softwoods are easier to shape and change.

So they're much easier to use on something like a building site where they need to change the shape and size of the wood very quickly.

But hardwoods are usually much stronger and more durable.

So they're often used for products that are intended to last a lot longer or to withstand a lot more use or weather and things like that.

So I've really enjoyed learning about this subject with you today and hopefully you'll join me again for another lesson.

But that's it for now.

I'll see you again soon, goodbye.