Pergola Questions.

[ozni]

Currently building a pergola from steel and wood. Using 100mm square steel posts by 3.1m long. Dug holes 300x300x800. From what I've read these would appear to be the correct size or have I over done it? Ran out of cement on last post so hole is only half full. Would there be any problem in topping up the last 300mm with another batch? The beam is patio tube 76x36mm or there abouts. I plan on using the same material for the rafters from the house to the beam - its a 3.5m span.The house is a steel framed tiled roof (no wooden rafters etc.). Does anyone know about attaching a leadger to these? The fascia is only shhet metal. I was thinking of strenghening the metal rafters with wood that goes back all the way across the wall plate and attaching some sort of angle brackets that would allow a leadger to be bolted through the metal fascia. Any thoughts or ideas would be great. I'm assuming that the steel rafetrs would be as strong as wooden ones for such a job. Wrong assumption?

Thanks Mac

[Spider]

I just built my pergola out of treated pine, and am about to place some polycarbonate roofing on it this weekend.
Your hole sizes are fine. Whilst it is not ideal to fill the last whole with a new batch on concrete, it should be OK.

[manoftalent]

Currently building a pergola from steel and wood. Using 100mm square steel posts by 3.1m long. Dug holes 300x300x800. From what I've read these would appear to be the correct size or have I over done it? Ran out of cement on last post so hole is only half full. Would there be any problem in topping up the last 300mm with another batch? The beam is patio tube 76x36mm or there abouts. I plan on using the same material for the rafters from the house to the beam - its a 3.5m span.The house is a steel framed tiled roof (no wooden rafters etc.). Does anyone know about attaching a leadger to these? The fascia is only shhet metal. I was thinking of strenghening the metal rafters with wood that goes back all the way across the wall plate and attaching some sort of angle brackets that would allow a leadger to be bolted through the metal fascia. Any thoughts or ideas would be great. I'm assuming that the steel rafetrs would be as strong as wooden ones for such a job. Wrong assumption?

Thanks Mac

holes are dug deep enough no problem, acctually deepest I have ever dug mine would be 700mm....the house being steel framed is not a problem ...you could build your pergola as a stand alone ......or lift up some roof tiles to "see" where the metal "studs" are and bolt 200 x50....treated pine/oregon....to the fascia....you could then fix joist hangers ...and run your rafters through to the metal framework, which you could use joist hangers again, they do come with both nail hole and bolt hole for this purpose ....although only using 76x36mm beams I would use 50mm hangers even though the rafters would be 75 x 50mm just make sure you have enough slope for water run off .......
To keep costs down I would probably use steel on the outer edge frame work., and posts...and timber inside ( joists& bearers )......