# Forum Home Renovation Pergolas, Gazebos, Strombellas & Rotundas  Looking for pergola ideas for existing rounded corner slab

## pantryfight

Hi all, bought our first home recently and are completely green to the whole renovation game. (thankfully the house doesn't need too much work) 
One thing however is that we have this rounded rear entertaining area with a rounded slab in a corner which you can see some photos of here: house - Imgur 
Although the real estate agent's plan makes it look rectangular with a heavily rounded corner, the slab is actually curved the whole way round as you can see in the pictures.  The 2 straight sides of the slab are 4m and 6m.
We'd like to build a covered pergola over this area. 
The only requirements we have really have are:
- no posts outside of the curved slab - the sloped area is driveway
- colorbond roof, possibly with polycarbonate skylight panel
- requires guttering - the sloped driveway will run the water straight back onto the slab if water is allowed to run straight onto it (if we had the water running off to the back like the flat roof of the house does anyway) 
Any ideas on what we can do with this pergola-wise? I've had a few thoughts but can't really imagine any of my ideas looking good or being possible engineering-wise. 
We'd be completely happy if it was just rectangular shaped and squared off with the shape of the house really, but would that be possible without putting posts in the driveway? 
Thanks all for helping a newb out.

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## chalkyt

Just going through the process of building a hexagonal pergola/gazebo. Google pergola or gazebo designs as there are heaps of web sites full of pics to give you some ideas. Generally you will find that you can DIY for less than half the cost of a kit or custom made. No pics on your post but I imagine that for the rounded part you can place 2 or 3 posts with beams running off them at 30 or 45 degrees (or whatever). Try ther blocklayer web site for angles/pitches etc, and for timber sizes the DesignPine web site has a downloadable span table that covers posts/beams/rafters/battens etc. Other web sites like TABMA and some of the timber suppliers also have basic tables that would cover your needs. 
Off the top of my head, I imagine that 90x90 posts on stirrups with 140x45 or 190x45 beams and 90x45 or 140x45 rafters would do the job. Colorbond roofing on 75x35 battens would finish it off. Good luck!

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## chalkyt

Just read your post properly and found the photos. Wot I said above still seems the way to go. Three or four posts, with F7 TP beams set into the outside of the posts and through bolted with M10. The concrete slab looks O.K. to take bolt down stirrups. 
 140x45 Beams will span3.7M and 190x45 will span 4.8M. I would run the rafters across the short dimension which looks to be about 4M. 140x45 rafters will span over 4M depending on their spacing (which is also an aesthetic issue, as is overhang and how they are finished on the outside. The Timber Qld Technical Data Sheet for Pergolas and Carports (19) has some really good stuff. (find it on Google). Fit ledgers to the brick walls under the existing eaves to support the rafters/beams and possibly knee braces to a couple of the posts to ensure stability (although cross bracing on the rafters would also be O.K.). You need a minimum of 2100 head clearance but you seem to be O.K. for this. Colorbond and Polycarbonate roofing plus guttering finishes the job on 75x35 battens run longways so the fall is towards the driveway and makes it easy to tap into the existing downpipe. 
You are probably only in N2 wind zone so the above probably overcaters a bit being the sizes needed for N3 (exposed countryside). Have fun, DIY you should get you out of it for under a couple of grand.

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