# Forum Home Renovation Pergolas, Gazebos, Strombellas & Rotundas  suitable beam & rafter specs?

## Savvas

Hi Folks, 
I've been discussing progress with my deck in the deck forum, but have belatedly realised that I should replace the now-decrepit 4.5mx4m 'lean-to' shelter pergola over the site first. That way I can avoid building over my new deck with hazards from ladders, dropped timbers etc. 
So I need a little advice re the timbers I'm choosing from the Bunnings catalogue. I'm taking my cues from the sizes of salvaged oregon and (in the case of the main fascia beam) redgum that I originally used when I built the pergola some 20 years ago.  
The 100x75 redgum posts are being replaced with 90x90mm TP with new Pryda footings bolted to the concrete.  
The 100x35mmx3m oregon rafters spaced at 900mm (& supporting a plastic sheet roof) that I used have held up well. I plan to replace them with H3 90x35mm x3m treated pine spaced at about 500mm. I'll use multiple 42x19 TP purlins spaced at about 500mm. _Will this size wood spanning 3 metres be OK or do I need to go to (say) 130mm?_ 
I think that the main hard-wood fascia beam (200x35mm) would also have held up well if I hadn't neglected to instal a gutter or ensure adequate sheet overhang. It was all done in a hurry so I neglected such issues and the fascia is now well and truly rotten and sagging! I plan to replace it with a 240x45mm TP bean (I think H4 from memory), supported at a max. span of about 2.5m and supporting a gutter!?  _Is this wider and thicker dimension required for TP over this span or could I use maybe a 35mm plank._ 
The original 4m sloping 'end beams' (not sure what they are properly called) are 200x35 oregon and have also held up well. I plan to replace them with 190x45mm TP. _Would 35mm thick still be OK in treated pine?_ 
Do these replacement timber choices sound OK? I'm particularly interested in hearing if people think:
- the choice of 45mm thicknesses for the fascia and endbeams is a good idea or if 35mm would be OK?
- my use of extra and more closely spaced (but narrower) rafters will be OK? 
The end beams bolt to existing veranda posts BTW and the rafters go into metal hangers on the house fascia _(I'm looking for a neater way to do this BTW...)._ 
I need to replace this pergola because I doubt it'll last another Adelaide winter and it's ramshackle appearance just won't 'fit' with my new deck ;-) I'malso  aiming for a slightly 'lighter' look about the whole thing. I'll probably finish the wood with the same clear deck oil I'm planning to use on the deck boards.  
Thanks in advance, 
Sam.

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