making roof trusses and joints

[happyhero]

Hi I am building a big shed and I want to build it with a Gambrel roof

http://en.wikipedia.org/wiki/Gambrel

I am going to make the trusses (I think thats what they are called) myself and I have looked in a few books (some American) that give information on building sheds with this roof shape. On some of them they cut plywood shapes out to fit over the joins of the 2"x4" and others they use metal plates, some which are used with nails and some that have a load of spikes. The plywood idea seems too long winded when you consider how many pieces you will need on each truss especially if you have to make many roof trusses. The favoured method seems to be the plates with spikes.

Firstly do these metal plates give you a strong structure? I have not used them before but it just seems to me joins made this way as opposed for example a join which is screwed and glued would be rickety, am I wrong? Also do you put them on both sides of a join?

Secondly the spiked type, can you get them here or are they only available in America?

Lastly anything else I should consider?

Any help appreciated.

 

[^woody^]

You can get nail plates, but I thought that the spiked plates had to be pressed in by a machine?

If you think ply gussets are long winded, wait until you've nailed a few plates!

 

[big-all]

your roof will need to be less than 4m high unless you have planning permision!!!!

 

[happyhero]

your roof will need to be less than 4m high unless you have planning permision!!!!

Yes I have watched out for that and should be 10cm or more within that without problem, including any bits stuck on roof that stick out etc. I was actually amazed after building fairly big shed walls how high 4m is, when you see how much roof I can add.

Where is the cheapest place to get these nail in plates, ie can you get them from any DIY places (would these be any good
http://www.screwfix.com/prods/35844/Building/Builders-Metalwork/Nail-Plates-76mm-x-152mm-Pack-of-50)

or do i have to go to a builders merchant for this sort of thing?

Do you put them on both sides of the join?

What length nails do I need if I am using 4"x2"?

What type of nail do i need?

How do I know what size plate to use if I am making this roof out of 4"x2"?

Finally what are they called so that I can search the net for them, have not had much luck so far?

 

[Deluks]

Shop around at builders and timber merchants (let those fingers do the walking...)

You can fix the spikey types with a block of wood on top of it, then several whacks with a mallet (or club hammer if you like to be obtuse)

 

[happyhero]

Ok I have been researching this in roof book I have and online and I have come up with another method, which would save me the plywood and metal plates it seems. Trouble is although I had a picture in a book I have spent ages trying to find it online to give a link but here is a picture, maybe not the best but you can enlarge it and see how it is built. It seems a bit like a pdf file and when you click on this link it seems to take you straight to page 195 which is where the diagram is. Click the plus to enlarge.

http://books.google.co.uk/books?id=...-05Rt-8&sig=Uj0A1JfErEsGqs6UQMDo0FIuwBk&hl=en

I would appreciate comments on this method, good bad or otherwise please.

Heres a better one

http://www.barnsbuilt.com/Gambrel_Barns.asp