Take the plunge and experiment!
A tale of two steps forward
a long moment to sit and ponder once more
Blithely pootling along, learning as I go, sliding round and round the subject of the roof, I’ve been working on the maths of the party-wall head (where the other semi is no longer attached); hoping that I could keep doing this, nibbling a bit at a time, circling towards the centre of the task, eventually arriving more or less where I should be going. Well that has been the theory.
Where to from here
Through exploring the shapes and angles I feel I’ve gathered a bit more confidence in the possibility of working this out but realise that I can’t ignore some major decisions on special features of the real house design any longer.
- Soffit boards under protruding lower edges of roof, from which the gutters hang
Reason for keeping: an integral part of the visual line/balance of design
- A total “duh moment” which should have struck me before. The large hip roof at side has a bell shaped lower lip giving the bottom of the corner ridges an up-tilted appearance and I’ve been ignoring it.
Reason for keeping: While circling the maths and mechanics of the construction, I came across an anomaly in my sums and the whole shaping because I ignored the shaping.
Problem: At both corners where the hip bottom corner butts up to the front and back, it is impossible to maintain the depth of soffit. It’s deeper at the corners because it’s an hypotenuse and it looks pretty awful – really sticks in the eye as it were. Is this the price for going with a deep overhang and ignoring the bell shaping of the hip which would make it appear shorter?
Also a bell shape flattens out the acute angle at which the hip meets the wall head, bringing it nearer to the horizontal so that the soffit and anything that hangs from it, like the gutters, are also sitting more or less horizontal too.
Triangles and yet more triangles
Trying out thoughts in foam board; seeing if I can gauge the relative measurements and angles and, hopefully, recognising when they work. Very much a case of “when found make a note of” preferably somewhere that I can’t lose them 😉
To soffit or not to soffit?
Reduce the soffit to almost nothing and take the easy path by tailoring lower edge to wall head, or play with the problem and see if I can work out a simple way of dealing with it?
Some parameters for deciding
Easy solution – just take the roof slopes over the edge sufficiently to hang a gutter under – that has a definite vote for ring to it.
Very possibly, but then I’ll miss out on the fun of trying for the other, and lose the visual of the swan-necked down-pipes as they sit close against the wall brickwork then swoop out to the overhanging roof edge guttering which sits outboard, as it were? (see photo of original house)
Not to mention also missing out on the way the soil-vent stack has to go through the roof tiling near the edge because of the soffit depth, making it look like the smoke stack on Popeye’s boat or Bluto’s periscope when he’s searching for Olive Oyl 😀
Simplest should be best
- Part compromise: if the corners where hip meets the main slopes can have cut back ‘noses’ to blunt them, that will certainly shorten the very odd visuals.
- If I can induce a small upward curve in the hip at the lower edge that too should help, with or without a deep soffit.
Cutting corners off is easy enough and making the foam board bend a little should be do-able.
- First let’s have a look at the whole soffit ‘thing’ by having another go at mocking up the depth and come to some form of compromise between its size and its appearance.
- Bend the odd bit of roof hip shaped foam
- Need to get a suitable ridge height so that there’s a better fix on the angles for the slopes.
- Hang some pieces from the ridge against the new soffit edge and look again at the whole profile of the shape.
- Need to work out exactly what is going on at the point where the triangular roof piece over the bay meets the front slope.
Lot’s and lots still to work out and do before having a run at a skeletal framework to support the actual roof materials.
Reckon it’ll keep me out of mischief. for a wee while at least?