I have drawings for an extension 5200mm wide and 4400mm long. The architect has specified a roof pitch of 20 degrees all round. This geometry means that about half the roof is the hip. I am wondering if the hip pitch could be steeper and allow a greater section of the roof to be spanned by the 5200mm engineered trusses? Any thoughts?
hip end roof pitch
- Thread starter elmsoft
- Start date
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Why?
Shorter the better, yes....but.
If you make the hip end a different pitch to the rest then you will create an angle anomaly that won't be a comfortable 45 degree cut.
Instead you will have the nightmare of alternating the compound cuts to suit the odd angles etc. Plus at a regular 45 degrees the off cut of one compound does the opposite side. Could work for an obtuse one I guess mebbe?
Also it will look a bit odd.
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Usually yes. they call this loose fill.
Your biggest 'mare will be sorting the hip rafter and cutting the top plumb cut and the bottom birds-mouth accurately.
The loose jacks should come with the compound cuts already done.
The hip rafter should be at 45 deg. on plan to ensure that the fascias are at the same level and soffits are the same projection on each of the three sides.
If you arrange the side hip at a noticeably steeper angle than the front and rear slopes, you will end up with a problem matching the eaves at the corners.
It's difficult to describe in words, but try it and see how far you get with it. You may get away with it if the slopes are not too different.
Why not save the bother and do a proper cut roof instead?
If you arrange the side hip at a noticeably steeper angle than the front and rear slopes, you will end up with a problem matching the eaves at the corners.
It's difficult to describe in words, but try it and see how far you get with it. You may get away with it if the slopes are not too different.
Why not save the bother and do a proper cut roof instead?
Not sure what you mean by a "proper cut roof"
And why it would be simpler?
A cut roof is just a traditional one, whereby all the pieces (rafters, hips, purlins etc) are cut on site - ie not consisting of manufactured trusses.
I believe it would be simpler because the angle of cuts of the rafters against the hips will be the same. In trying to save work by using more trusses (ie shortening the hip-slope in plan) , you will have more complications with the rafter/hip angles, and also at the eaves.
I believe it would be simpler because the angle of cuts of the rafters against the hips will be the same. In trying to save work by using more trusses (ie shortening the hip-slope in plan) , you will have more complications with the rafter/hip angles, and also at the eaves.
Just a comment to agree totally with all above.
The old cut-roofers nightmare of unequal intersecting pitches can be overcome, even to the extent of giving a level fascia.
But its not a job for a DIY'er or the faint hearted carpenter.
A guy once wrote a book attempting to explain these kind of roofing irregularities in mathematical terms - apparently, by the time he published, he'd also lost his mind.
The old cut-roofers nightmare of unequal intersecting pitches can be overcome, even to the extent of giving a level fascia.
But its not a job for a DIY'er or the faint hearted carpenter.
A guy once wrote a book attempting to explain these kind of roofing irregularities in mathematical terms - apparently, by the time he published, he'd also lost his mind.
@OP;
To show diagrammatically the nature of your problem at the eaves, see attached sketch.
With a level wall plate, equal eaves projection and differing angles on adjacent slopes, you can see that the fascias will be at different heights, so what would you do at the base of the hip where the two slopes met?
As ree, the problem can be overcome but it would need forethought and considerable skill - probably beyond diy competence.
And as for the problems with the rafter/hip angles, I personally wouldn't know where to begin
To show diagrammatically the nature of your problem at the eaves, see attached sketch.
With a level wall plate, equal eaves projection and differing angles on adjacent slopes, you can see that the fascias will be at different heights, so what would you do at the base of the hip where the two slopes met?
As ree, the problem can be overcome but it would need forethought and considerable skill - probably beyond diy competence.
And as for the problems with the rafter/hip angles, I personally wouldn't know where to begin
Hip roofs are a 'mare whether they are cut roofs or trusses.
When the trusses get delivered you think "wow" who is gonna sort all that lot out!
You not only have all the loose fill roof stuff but also all the loose fill joists etc, that are also a pile of fiddly sticks on a hip end.
Another thing is "where do I start?" This IS important or you will make a real hash of it especially when you are marrying into an existing pitch. There will be mono trusses and girder trusses that will dictate a starting point but a diy'er won't be aware of this.
As for actually constructing the hip end, it matters not whether it is trusses or cut roof, they still require a lot of effort and skill.
Definitely not one for the uninitiated. You would not believe the amount of tools you need either to make a job like this run smoothly!
As for the weather....!
When the trusses get delivered you think "wow" who is gonna sort all that lot out!
You not only have all the loose fill roof stuff but also all the loose fill joists etc, that are also a pile of fiddly sticks on a hip end.
Another thing is "where do I start?" This IS important or you will make a real hash of it especially when you are marrying into an existing pitch. There will be mono trusses and girder trusses that will dictate a starting point but a diy'er won't be aware of this.
As for actually constructing the hip end, it matters not whether it is trusses or cut roof, they still require a lot of effort and skill.
Definitely not one for the uninitiated. You would not believe the amount of tools you need either to make a job like this run smoothly!
As for the weather....!
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