Waaw so helpful thank you

Fantastic informative video 👍

Can rafter be unequal in the building code? I have a flat roof, and need to design a gable but the chimney is right in the middle, so I need to make a rafter shorter than the other

@martineisbrenner

6 жыл бұрын

Rafters are sized according to the tables in the National Building Code according to span so yes, they can.

Hi Martin, how do you get to the slope gain factor? I can follow everything your doing, but I got confused when you started multiplying by the slope gain factor??? Yet again any advice would be greatly appreciated thanks again Steve

@martineisbrenner

5 жыл бұрын

The slope gain factor is helpful for calculating the length of the rafter when you know the run of the common rafter. If it was a 6/12 roof the calculation would be 6÷12=.5. Then take .5 and square it .5²=.25. Then take .25 and and 1 = 1.25. The last step is to take 1.25 and find the square root = 1.118. Then take that and multiply by the run of the rafter. Presto!

@ssjktjessica6

5 жыл бұрын

Thank you, I've got it now, much appreciated 👍

@kushnastay

4 ай бұрын

Rise divided by run = x squared plus 1 than square root that= slop gain factor for 90 degrees For a hip it’s almost the same except after your square your number you would add 2 instead of 1 , then square root it

how you get the 1.202 number?

@martineisbrenner

Жыл бұрын

Hello @juniorpalomera-garcia7448. That number is a handy trick that takes the slope of the roof and converts into a number that when multiplied by the run of a rafter, results in the sloping length of the rafter. A couple of comments below this there is an explanation on how to find the SGF.

Hi there again ,I know that imperial measurements Express pitch as 4 over 12 or 6 over 12 ,how do you Express it in metric increments?? Is it 30 mm over 300mm ?? Please help 👍🏻

@martineisbrenner

5 жыл бұрын

Hi Steve. Back in the day when metric was adopted all the square manufacturers wanted to be the ones to decide the basis for run. I have heard of three different numbers, 250, 300, and 1000 mm. The Chappell metric square uses 300 mm. Therefore a 6/12 would be the same as a 150/300.

@martineisbrenner

5 жыл бұрын

I also recall the Frederickson Metric framing square but don't recall the base unit that he used.

@adebad1

3 жыл бұрын

@@martineisbrenner can one not just use the imperial unit slope triangle to work out the rise in metric if one already has run in metric?

The left hypotenuse is the wrong length

Nice to see you working in metric 👍🏻

@martineisbrenner

5 жыл бұрын

Thanks Steve! It's a real mixed up situation here in Canada. Housing is practically always done in imperial and commercial is usually metric. I teach at a government funded institution so it's usually metric.

Disregard everything I am wrong

It should be 1820 instead of 2035

You left side measurements are wrong

@martineisbrenner

5 жыл бұрын

Where do you see a mistake?

Do this video in feet