Ridge Board Length

[Medic1]

Hi

What's the best formula for calculating the ridge board length for a hip roof?

Regards Medic1

[Ozcar]

I'm no authority, but since nobody else seems to want to chip in...

My calculation says that for a roof on a simple rectangle with sides L and S (for Long and Short), the ridge length would simply be L-S.

My initial thought was that the ridge length would depend somehow on the pitch of the roof, but it doesn't look like it does – as long as the pitch on the short and long sides is the same.

Of course, I could be totally wrong.

[Blocklayer]

There's more than 1 way to calculate ridge length, but most use L-S (as Ozcar said) then add the thickness of a common rafter, so the 2 end jacks are the same as commons. If you don't add the thickness of a common rafter, the end jacks will be slightly longer.
This works, unless the ridge and commons are different thickness, which alters the end jack length.

If you look at this calculator and change the ridge thickness, you'll see the end jacks change.
Roof Framing Calculators - Hip + Gable Roof Framing - Online

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[Medic1]

Thanks for the input, your online calculator is a fantastic piece of software!!

[TermiMonster]

There are 2 ways of working it out, dependant on how you want to make your hip cut. Your hip can have a single bevel cut or a double bevel cut.
The formulae are difficult to explain, but the easiest way is to make a drawing of the joint you want, actual size, and measure how much the ridge must extend from that (at each end).
Hope that makes sense.

[Bloss]

There's more than 1 way to calculate ridge length, but most use L-S (as Ozcar said) then add the thickness of a common rafter, so the 2 end jacks are the same as commons. If you don't add the thickness of a common rafter, the end jacks will be slightly longer.
This works, unless the ridge and commons are different thickness, which alters the end jack length.

If you look at this calculator and change the ridge thickness, you'll see the end jacks change.
Roof Framing Calculators - Hip + Gable Roof Framing - Online

:

Blocklayer's site is an absolute gem!