Browse Forums Building Standards; Getting It Right! 1 Sep 30, 2016 7:59 pm Hi all I'm struggling to interpret the span tables in AS1684 I'd like to know the following 1. What size beam required on the 9.2m side if it only has to span 3m ish. 2. What rafter size to span 3.6m I want to keep them as small as possible as I want to minimise how far below the facia they stick. I've attached a pic to help. Like ⋅ Add a comment ⋅ Pin to Ideaboard ⋅ Re: Timber span tables 2Oct 01, 2016 11:05 am Hi Crazyk I am not a big fan of that detail Reasons 1. Change of function? Consider it's an open pergola now will you be putting a roof/shade cover on it at a later date? 2. You also haven't considered/details beyond what's already there the roof rafters and wall plate connections? 3. Wind loading and hold down provisions? 4. Effectively you have increased the eaves overhand by half the width of the pergola & connecting to the fascia is inadequate due to the above. BTW nice rough sketch tho you need connection details & Photos Designer,Engineer (Civil,Const & Envir),Builder,Concrete & Masonry Contract.Struct Repairs Re: Timber span tables 3Oct 01, 2016 2:39 pm Given the size of pergola you are proposing it will require a building permit in which case you have to have it professionally drafted and comped and including connectionist existing rafters and not forgetting bracing and ground footings. Foremost Building Expert in Australia,assisting with building problems/disputes, building stage inspections,pre-contract review advice for peace of mind 200 blogs http://www.buildingexpert.net.au/blog Re: Timber span tables 4Oct 01, 2016 4:04 pm Thanks guys I do understand that I'll need a permit. No worries there. Anything above 8m2 from memory. What I'm trying to do is understand what I can use before going to the design stage. I've already been led down the garden path with my builder, trusting in them with their knowledge and expertise, only having to learn it all to see how wrong they were. And to run on the basis that whoever I get to do engineering will do it right....yeah whatever that's what I thought when the built my house. So in order for me to become more educated and question engineers or designers can anyone assist? My fascia is a non structural fascia so I'm going to have to tie in some very long steel brackets that support the ledger beam independently of the fascia. These will be tied to every truss. Re: Timber span tables 5Oct 01, 2016 6:04 pm ![]() My fascia is a non structural fascia so I'm going to have to tie in some very long steel brackets that support the ledger beam independently of the fascia. These will be tied to every truss. Rafter straps here http://wesfab.com.au/brackets.html You will also need to trip-l-grip each rafter to the wall plate Do you have hold down rods into the wall plate cast into the footings? I'll put up a detail here https://www.softwoods.com.au/assets/upl ... racket.png Cheers Designer,Engineer (Civil,Const & Envir),Builder,Concrete & Masonry Contract.Struct Repairs Re: Timber span tables 6Oct 01, 2016 7:32 pm Thanks yeah I thought about that but not sure the existing gutter would cope with the extra water runoff. From what I've read the tie in strap should also go past the wall stud for strength. I am also contemplating putting the roof on top of the existing roof set back 2 tiles. Not a real fan of it though Re: Timber span tables 7Oct 02, 2016 7:03 am 3m spacing I would use anything on or above 190x45 treated pine. Side beam 190x45 again Whaling plate 90x45 Re: Timber span tables 8Oct 02, 2016 9:03 am ![]() I am also contemplating putting the roof on top of the existing roof set back 2 tiles. Not a real fan of it though If you do that you could use brackets like these to tie in to the trusses: http://www.roofextenda.com.au/re-index.php Not sure if they are any good, but that's something I've thought of using if and when we put a cover over the soon to be deck. Re: Timber span tables 9Oct 02, 2016 9:15 am ![]() ![]() I am also contemplating putting the roof on top of the existing roof set back 2 tiles. Not a real fan of it though If you do that you could use brackets like these to tie in to the trusses: http://www.roofextenda.com.au/re-index.php Not sure if they are any good, but that's something I've thought of using if and when we put a cover over the soon to be deck. Oh yeah I see they screw to the truss and too plate. Looking at pictures on the internet they don't place them on every truss so I'll need to get the designer to work out wind load and number them accordingly. Re: Timber span tables 10Oct 04, 2016 6:45 pm ![]() 3m spacing I would use anything on or above 190x45 treated pine. Side beam 190x45 again Whaling plate 90x45 Sorry I just saw this post. Are you basing this advice on gut feel or the AS span tables and what sort of timber? Treated pine, hardwood etc and grade. Timber span tables 11Oct 04, 2016 8:04 pm That's what I used on 3 pergolas with no issue if you need span tables can have a quick look In general, a member continuous span means it’s continuous (one whole piece of timber/steel or any material) over at least three supports (two spans). Single span means… 1 9389 So, how is the comparison between the two ( Alpha and Hebel ). Do you still put the yellow/red tounge over the alpha also or it's not required and their noise reduction… 16 18427 I'm in the same boat. Many many years ago the rear timber fence fell down & was replaced with colorbond. We have a 2nd fence falling down (3rd fence not far off). Pricing… 1 18825 ![]() |