cut and pitch

[chirpychippy]

How to start this post? I can cut and pitch the following, gable, hip, and irregular hip to a degree, but i am in essence still new to the cut and pitch game which is why I need the assistance of someone that has experience in this field.

I have been given drawings for the a conversion my employer has taken on and being the only chippy in the company it falls to me to work the roof out and pitch it. But I am somewhat stumped.

The property is a bungalow with a standard gable roof and a flat roof extension to the rear running the width of the house and the garage. Whilst the front of the bunglaow will remain intact we will be adding a hipped roof to the rear encompassing the garage and the existing flat roof extension.

The new hipped roof will be 900mm above the existing gable roof height and will be connected by way of a broken hip. The roof plan illustrates that the valley hip which is to be pitched to the existing ridge and intersect the broken hip is to put in at 40 degress "the all round roof pitch by the way is 35 degrees" whereas the external hip which pitches to the new ridge and is adjacent to the valley hip be pitched at 45 degrees.

This is where I am stumped, I would have thought that the valley and the hip rafter should run parallel to one another not have a 5 degree difference or is it because the hip and the valley are pitched at different heights then the 5 degree difference is the offset to allow the valley jacks to run true.


Thank you for your patience and I will be pleasantly surprised if anyone can help, cheers.

 

[gregers]

yep you lost me,


amazing ive been a chippy for over 20 years,but alas i never got into doing roofs wish i had in hindsight,helped on a lot,but take my hat off to the chaps who understand all of this.
worked with someone who used logrythium tables,amazing how he worked things out.

good luck fella.rather you then me

 

[noseall]

I don't know why the valley and hip blades are set at different angles other than one has to travel further (i.e. longer) than t'uther?

 

[joinerjohn]

I can't understand why it has been planned with a new hipped roof 900mm higher than the existing gable. Is the width of the garage at the back, perhaps wider than the bungalow?

Seems to me , it would have been better to retain the existing roof pitch and extend this over the extension and garage.
Perhaps you could scan the drawings and post them on here?

 

[ladylola]

Are both new and old roofs the same pitch, or to put it another way is the new roof steeper than the exsisting?

 

[WestmidsChippy]

go to the job and get your tape out.
measure, sit back for 5 and work it out.

if it is not ringing right in your head then mr architect is destined for a call.
he could of made a cock up or as poster says, further then t'uther.

only going on what your telling me

 

[^woody^]

Definitely post some sort of sketch, I can't make head or tail of the text

 

[ladylola]

The new hipped roof will be 900mm above the existing gable roof height and will be connected by way of a broken hip. The roof plan illustrates that the valley hip which is to be pitched to the existing ridge and intersect the broken hip is to put in at 40 degress "the all round roof pitch by the way is 35 degrees" whereas the external hip which pitches to the new ridge and is adjacent to the valley hip be pitched at 45 degrees.

.

Just re read this.
If I'm reading it correctly then the original roof is set at 35* and the new roof will have a pitch of 45* and the two ridges are at 90* to each other.
So that gives a 45* intersecting a 35* which is why the valley hip 40* i.e. neither a 45 or a 35.
So the external hips at the rear of the property are pitched for the 45* which means that the two small broken hips will need to be set at 45* in relation to the sides and 35* on the front aspect to allow the front exsisting roof slope to carry on up the new small hipped end.

I think that's it

 

[gregers]

blimey,my head hurts just reading that reply

 

[ladylola]

blimey,my head hurts just reading that reply

Think what it would be like working in a roof with all those different angles, bending for a 45* pitch and walking into a hip at 35* , now that'll make your head hurt!

 

[noseall]

The hip/valley blades are always at a different angle to say the commons or jacks of the same roof, regardless of pitch. They are always shallower due to the longer going.

It is the fact that the hip and valley differ from each other that i find hard to grasp.

 

[chirpychippy]

I will see if I can get hold of the plans again, I have given them back along with a suggestion that he get someone more experienced than myself. Its quite annoying though as I would have liked to have figured the roof out for myself, thanks for your replies on this subject though.

Whilst on the subject of pitching roofs, I taught myself how to pitch gable and standard hipped roofs using the Run and Rise method or Pi and am continuing to teach myself from a book by the name of Roof Framing by Marshall Gross. The situation is this, I went to evening college about 8 years ago qualified as a Carpenter whilst working in the Care industry, got a job with the builder I am working with to this day initially as a labourer and basically learnt my trade as I went. I would like to learn to pitch all sorts of roofs but obviously hands on experiences of this nature are few and far between in my current job. So, do you reckon I can teach myself from a book or is there another avenue I should take?

I will try and get the plans, thanks again.

 

[noseall]

. I would like to learn to pitch all sorts of roofs but obviously hands on experiences of this nature are few and far between in my current job. So, do you reckon I can teach myself from a book or is there another avenue I should take?

I learned everything i know about cutting roofs from watching other carpenters and actually building them myself. I am fairly competent at trigonometry and math's in general so this helps and is used a lot.

You can only learn so much from a book. You must find some way of getting hands on experience. Also, being financially responsible for your work is a true and stern test.

I really enjoy building cut roofs especially finishing the soffit detail. All of my work is building extensions so i am largely governed by existing roofs. I would not say that this makes my job any more difficult than new build but it certainly gets the juices flowing especially when you uncover an existing roof in the middle of winter!!

 

[chirpychippy]

Thank you Noseall, I am going to percevere with the book, but I also appreciate that hands on experience can't be beaten.

Could I ask you some advice though, I am now 37yrs of age, I have been doing chippying for nearly six years as previously mentioned, I now know that with my current employer I am not going to get the hands on experience i need, which seems I am left with one option and thats to look for a larger employer. One that could assist me in learning cut and pitch as the opportunities arise, do you think this is feesable?

Thank you again

 

[joinerjohn]

I'm afraid that cut roofs are becoming a bit if a dying art these days. I'm not even sure if they do them in the NVQ's nowadays. Most building sites use ready made trusses. Last cut roof I did must have been over 6 yrs ago now, and the one before that would have been at least 10 yrs ago. Very far and few to say the least.
Did you manage to get the drawings for this roof so you could scan them in and post on here?