Hi, I need to build a few '4 sided roofs' (hip roofs ??). Rather than using the 'cut it and see if it fits method', is there a 'proper' way to work out the size and shape of the four 'sides' and then lay that out on flat card ??
Cheers Mal Oz
P.S. if your wondering, I'm attempting to build the old GE station that was located in Haverhill in Suffolk. Alas its all gone now.
P.P.S. some colour pix (of the old station) would be luverly if any one has them !
You need accurately scalesd side and end elevations of the roof.
For the triangular sections of the hip roof, measure the length of the slope in the side elevation - that will be the _height_ of the triangle. From an end elevation, get the length at the eaves. That will be the _base_ of the triangle. You now have enough data to draw the triangular section of the hip roof.
Draw a horizontal line, mark off the eaves length, and bisect it. On the bisecting point, draw a line at right angles, and mark off the height as measured above. Connect end marks of the eaves and the end mark of the height, and there's your hip roof segment.
For the trapezoidal sections of the hip roof, use the eavea length from the side elevation for the base. The ridge length will be the opposite side. The slope seen in the side elevation will be the height of the trapezoid. That should be enough for you to draw it.
You will probbaly still have to do some cutting and fitting, though, as there will be measuring error. Trust me. :-)
Having just built the body of a BR grain hopper in Plastikard using my CAD program to do the development of the sides, I can confirm that a fair bit of cutting, chamfering and fitting is required, especially if you use a comparatively thick material to construct the shape. Nothing is at right angles and it takes a fair bit of trial and error to get it right - and a bit of body filling putty as well :-) With a roof you might not be too worried since you will probably be covering the base with tiles or slates in any case, and a big wodge of glue down the inside of the join might suffice :-)
Thanks for that. I only have very old fuzzy b/w photos of the subject and getting accurate measurements from that will be difficult - as it is the length/height/width of the building has been guestimates to say the least. But I can adapt the points you gave me to sort something out.