Constructing pyramid roof

[tom patton]

Hi all. I will soon be constructing my pyramid roof in 200x45 rafters.It is 6.1 metres square by about .8 metre high.It has a centre post and doubled rafters at the corners all laid on a 400mm high upstand.It has rafters at approx 600 centres and they are connected by purpose made skewed hangers to match the 15 degree sloped roof held by tie straps and truss clips at the upstand. How do I get the rafter profiles top and bottom-is there an easy way? Do you put in the middle rafter on each face and work out? Do you saw off the vertical "birds mouth" last for the facia board?

[Rick]

I have never done this, but am happliy framing away my first roof,

I would make a triangle first forming opposite corners of the pryamit, with the top vertical faces flat. I'd then put up the other corners flat to the first triangle. What I would not do, is try to mitre the 4 corners together at the top. To get the sides exact, the second two corner pieces would be just a bit shorter than the first two.

I'd work out my rafter centers, and have it symetrical, so either one in the middle, or 2 each side of the middle.

This is gonna take ages to do, I am running at about 60-90 minuites per rafter on my roof right now, and I have 60 odd to do.

If possible I'd build this on the floor, then take it apart, lift it up, and assemble.

Rick

[tom patton]

[smudger]

you do cut your rafter feet once all are fixed, use a string line to get straight line, if you have a fixed point top and bottom you can use a string line pulled between them to get all your angles, on the plate line you will have to allow a bit for your backing (the bit left on where you cut your birds-mouth) at least half the depth of timber,

[tom patton]

Got the rafter hanger bracket prices £20+VAT each I need 32 so its standard rafter hangers for me £3 each.I will get advice from the structural engineer who has been really helpfull--I am finding construction costs expand to meet your budget.

[Rick]

Construction costs expand to exceed your budget ..........

I have a desire to use local items on my build, so I have had wood from the forrest out the back of the house. For C16, I have made the stuff 50% thicker, for C24 I used Oak. As most of the woodwork is exposed, I have been able to be very picky about what bits I use. This means none of the standard metalwork fits. I have used "Universal Framing Anchors" from screwfix, at about 20 pence each.

Rick

[tom patton]

Yup I agree keep things simple.I saw the brackets in screwfix and they look as if they would be ok for my pyramid roof.I got a price for C24 220x45 its quite a modest price £2.20 per metre+VAT I need 100 metres so its not expensive in construction terms in fact wood is almost as cheap as block cement sand etc its the "bits" that run up the budget eg 5 skips at £100- tool hire-specialist things eg I took my eye off the ball and my 4 hardwood windows cost £1700 did nt have time to get quotes.My zinc roof is £70 per square metre labour[50+metres] so I will be practicing my old O grade soldering skills-perhaps buying a new professional plumbers torch that runs a propane mix-although zinc melts at 400C-perhaps needs some practice on zinc first!. I find I must keep on top of prices-always-get 2 prices-my local builder supplies company-big chain-wanted £20 per board for cavity insulation boards when I said I thought they should be around £4 per board he immediately said I could have them for £3.92.I needed 90 boards that could have been a very expensive mistake!.

[Rick]

You have found the stuff that really gets me going.

In my walls, the insulation costs more than the bricks/stone/sand/cement added together (I have free stone), the foundations cost me more than the walls, a grands worth of steel mesh in there never to be seen again. A bag of cenent ranges from 2.50 to 5 quid depending where you get it from.

In the roof, again the insulation cost almost as much as the welsh slate, and the wood cost about the same again (lots of oak).

I am looking at about 500 quid worth of nails/fixings for my roof, I need long (expensive) fixings for the "over rafter" insulation.

I am guessing the leadwork I need doing is going to run the materials cost up a good way.

Its the little bits and bobs that run the bills right up.......

I grt the prices from a cupple of web suppliers, then phone round for stuff, sometimes the less obvious people are cheepest, hence all my blocks & sand comming from B&Q.

I have a roofer round next weekend to give me some lessons. I guess I will do the major "long slog" work in the middle of the roof, and get him to do all the edge details.

Rick

[tom patton]

I see Homebase are selling cement at £3.42 per bag thats cheaper than anywhere-but- I am only using 15 bags so I would save about £10 buying it there. Try Build Base for your insulation-but-like you I have found it astronomically expensive-dearer than 7N breeze block--thats daft. If you intend to do the lead yourself will you be using oxy/acetylene I ve got a BOC mini pack oxy bottle and just use throw away acetylene. I am working on the logistics of zinc roofing it looks D-I-Y able with a little soldering and a lot of thought.D-I-Y is possible for almost every building operation.Its just painfully slow eg prepare my foundations-remove soil 8 compacted cubes-set reinforcing mesh-pour readymix build foundation pour sollum[base]- by hand using rotavator 2 weeks £800-using machines contractor 3 days£3200+VAT - both excluding 4 days setting time-

[Rick]

DIY is I have found possible with almost all of a house build, and like you I find it slower than getting a professional. However I do just love to sit back and look at what I have done, a very pleasurabe experience. I also find working out how heavy my walls are, or my roof is, to see how many hours at the Gym I have saved by doing something usefull to get fit ......

I agree working with machines on a DIY basis can get expensive, as you are slow - but its really good fun. I found a guy who has machines & hires them, and I get them at the weekends, so he drops one off on his way home Friday night, and collects it monday morning. Its worked out quite well.

Rick

[tom patton]

Like you I have found tool hire a great saver of time and energy the biggest to date-a cobra self powered concrete breaker-being disabled I do nt have enough strength to hold it so my wife and I hung on to it while breaking 6 inch concrete-very hard work.I m getting a caterpillar tracked machine for digging my soil pipe trench 8 cubic metres of compacted soil so it should be fun. One of the irritating things about my project is that most of it will be covered up!!.

foundations-remove