# Forum Home Renovation Pergolas, Gazebos, Strombellas & Rotundas  Pitched Pergola design choice- truss or suppoted ridge beam?

## stever12

Hi, 
I am going to build a pitched pergola on a raised deck at the back of my house.  It will all be constructed out of treated pine. The pitched span is 5.3m (the pitch runs parallel with the wall, ie the ridge beam is perpendicular to the wall) and the length is 4.2m. I have a concrete tiled roof. 
I am not sure whether to use a supported ridge beam (with a roof extenda bracket secured to the stud wall at one end and a post at the other) or trusses? Could someone who has experience with either of these point out the advantages and disadvantages of both methods?   
I am leaning towards the supported ridge beam, due to the fact that I can bolt it in place and then measure up the rafters in situ.  I have no experience with truss design or fabrication so the A frame method seems a bit daunting. 
Any help would be appreciated.  :2thumbsup:

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## SilentButDeadly

Trusses are easier & faster to put up but more expensive to purchase and install (because yours will probably need a crane due to their size).  They can also reduce the feeling of height overhead because of all those bottom chords. 
One option is to go with a truss at either end which supports a ridge beam between the two which is then stocked with rafters (which is what I did).  Another is to go with the full end trusses but infill with scrissor trusses which don't have a bottom chord. 
Get someone to measure, design & build the trusses...(I did)...they are easy to install - certainly easier than a ridge and rafters.  If you feel you msut build them yourself then the Roof Building Manual by Hiddle and Staines is invaluable http://www.skillspublish.com.au/BK13-06.htm

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## stever12

Thanks SilentButDeadly, sounds like a much better idea than what I was thinking of.  I'm more than happy to call in the professionals as I am having some roof trusses made up for an extension to the house any way. 
I like the idea of trusses at either end supporting the ridge beam and stocking the rest out with rafters.  Some more questions if I may: 
- Were the end trusses you had fabricated a complete A-frame, or was there a space left at the top for the ridge beam to slot into, therefore completing the truss? 
- If it was a complete pre-fab truss, how did you support the ridge beam from the truss? 
You mentioned I would need a crane to get trusses to span 5.3m into place.  I don't have access to a crane, so in your opinion, for the width of the pitched section I require, should I abort this design?  I would hate to buy trusses and get them in the back yard only to realise I've got no chance of safely installing them!!

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## SilentButDeadly

- Were the end trusses you had fabricated a complete A-frame, or was there a space left at the top for the ridge beam to slot into, therefore completing the truss?
- If it was a complete pre-fab truss, how did you support the ridge beam from the truss?  They were a complete A frame and the LVL ridge is supported on a hardwood block and held in place by a pair of heavy duty galvanised steel angles and bolted through. I positioned the block and one of the angles before the trusses were lifted into position. Once both trusses were fitted, made plumb and braced I could measure and cut the LVL beam to length and then have it lifted into place.  http://www.woodworkforums.com/blog.php?b=502     
You mentioned I would need a crane to get trusses to span 5.3m into place. I don't have access to a crane, so in your opinion, for the width of the pitched section I require, should I abort this design? I would hate to buy trusses and get them in the back yard only to realise I've got no chance of safely installing them!!   You always have access to a crane......I hired mine. Franna with two professional operators. Three hours for $420.......money well spent. Especially since it took at least two of us just to carry the thing - there was no way we were going to get it over our heads

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