LAUREN:'Today's Dengineer is nine-year-old Astrid from Brighton.
ASTRID:Please Dengineers, I love Christmas so much that having it once a year just isn't enough.
MARAL:Are you ready to see your design? Here we are.
ASTRID:Wow. It looks amazing.
MARAL:I've come up with a little log cabin decorated with everything to do with Christmas. So we have kind of deep reds, greens and a little bit of brown for the log cabin. Do I get a thumbs up for the design? Can we begin?
ASTRID:Definitely.
MARAL:Yes, let's do it.
LAUREN:'Maral's come up with the ultimate festive fun pad. 'The outside of the den will be built to look like a traditional log cabin 'and Father Christmas will even be trying to make an entrance 'via the chimney.
LAUREN:'Inside there'll be a cosy fireplace to curl up by 'and an arts and crafts station 'for Astrid to create her very own decorations.' Ah Maral, I see you've brought me a nice little snack. Thank yo鈥
MARAL:Uh, it's not for eating, it's for demonstration purposes.
LAUREN:OK, don't touch it. What's it all about?
MARAL:So this is very similar to Astrids Christmas den and one of the main features is actually the pitched roof.
LAUREN:So what's a pitched roof?
MARAL:A pitch of the roof basically is the way that we measure the steepness of the slope of the roof. So Astrid's den has a 30 degree angle which is typical of log cabins.
LAUREN:So why don鈥檛 we just use like a flat roof? It would be easier for all of us wouldn't it if we just put a flat roof on it right?
MARAL:It would be a lot easier but here's a flat roof. If there was a lot of snow falling onto a flat roof it would be a lot of weight to carry and there wouldn't be anywhere for the snow to melt or for the water to go to.
LAUREN:It's just going to sit there right on top.
MARAL:It's just going to sit there like this.
LAUREN:OK.
MARAL:And if we add a bit of pressure鈥
LAUREN:Oh, so we don鈥檛 want that.
MARAL:The roof just collapses. There is a lot of weight to it. With the pitched roof over here if we have snow that's falling鈥
MARAL:the gravity will pull it down.
LAUREN:It is, isn't it?
MARAL:Gradually.
LAUREN:Like it's just falling really, really softly rather than going through.
MARAL:Exactly.
LAUREN:'Maral has designed Astrid a traditional log cabin 'with a pitched roof at an angle of 30 degrees. 'This means Astrid's roof is not too steep or too shallow 'which will allow snow and rain to fall off gently.'
Presenters Lauren Layfield and Joe Tracini and The Dengineers team help Astrid from Brighton create her dream of a Christmas den.
They investigate the steepness of the slope of the roof and how important this is in climates where there is a great deal of snowfall.
They compare a pitched roof with a flat roof and demonstrate how the weight of the snow on a flat roof will cause it to collapse, while on a pitched roof the snow and rain will fall gently off the sides.
Teacher Notes
This could be used to introduce the process of design, and as a prompt for class discussion and learning in areas such as initial research, designing and making a structure.
They could investigate how important is the pitch of the roof, testing how much weight and pressure roofs with varying pitch can handle.
Curriculum Notes
This clip will be relevant for teaching Design and Technology at KS2 in England, Wales, and Northern Ireland and 1st and 2nd level in Scotland.
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