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Introductory Post - 50m2 Deck/Pergola

HandyAndy
Building a Reputation

Introductory Post - 50m2 Deck/Pergola

Hi All,

just wanted to kick off by saying hello and introducting myself, my name is Andy, live in south west vic, I am an electrician by trade, working in an electrical (light engineering) design/drafting role and the big boss has been hassling me to get on to our outdoor area, we've been in the house for about 5 years so time to get cracking.

due to my role and skillset, i have decided to take on the design/drawings myself (using AutoCAD, although this BIM software i read alot of on here seems interesting), which i intend to have reviewed by a structural engineer before submitting for permit approval, and i will likely tackle the build also.

 

I have come across this site in many of my google searches to gain inspiration and find answers, it is a great community here, hoping i can get some project specific advice and wish i can also add some value by contributing and sharing my journey.

 

the deck layout is pretty much set, and design is almost complete still trying to determine some minor details (footings - we have clay soil and i have 2 soil reports with varying information and some terminology that doesn't return a defining google search).

the deck will start in my existing concreted alfresco and span ~9m long ending at a 400mm high retaining wall by upto ~7m wide (unusual shape) to run along the fence line.

 

deck layout.JPG

our house is full of tasmanian oak features, so we have decided to go with 140x22 Silvertop Ash decking boards.

 

i will be using pryda post anchor (stirrup) mounted bearers likely 2/120x45 with 120x45 inline joists, spans and load widths vary due to the unusual shape, but 1800 max. bearer spans, and biggest load with is ~1100.

 

unfortunately, i had to put a ledger along the house due to having inline joists (to avoid a large gap between the house and the deck), i will be asking for advice (possibly from a pest specialist) on what is required for termite protection in regards to this. unless someone has an alternative to the ledger board.

 

i am interested in any feedback people have for my selections and materials, i have been using a "Decks & Pergolas Construction Manual" i bought from bunnings a while back in conjunction with AS 1684.2.

 

over the existing slab i will be using 90x45 joists fixed with klevaklip adjustable joist supports. we would like to deck flush upto the sliding doors (over sill) so a finished height from the concrete slab is 157mm putting top of joist at 135mm.

 

footings near the retaining wall are a little tricky, due to the moisture present and the finished height of the footing (for termite protection) has to be lower than the retaining wall, so i have given my bearers a little overhang to keep away from the wall.

the retaining wall is constructed with treated pine sleepers and doesn't have any dedicated drainage.
i am thinking of sloping the base of the retaining wall down to my finished ground level, i may need a realm drain length ways under the deck to try and direct any water or moisture.

 

the pergola has been a bit of a mission to try and negotiate, due to the location, shape and proportions of the house, the pergola needs to be L-Shaped with the internal and one end against a wall, skillion roofs weren't looking great, gable ends didn't really suit the style of our house and a hip-roof seemed excessive and over-complicated for the space, then i had this "Grand Idea", our house facade (the Pagoda) has some rendered features, columns with a large landing at the front with a big square arch way, i thought it would be great to compliment the house by incorporating that in to the pergola.... a week later, i finally finessed the design (not 100% sure on the structural integrity as yet) and... well.. talk about excessive, haha.

 

pagoda facade rendering.jpg

not my house pictured above.

.

front.JPGrear.JPG

side.JPG

 

floor.JPG

these "structures" will be cement sheet (or blue board foam) covered and render, housing 3 150x150 posts with 2/240x45 bearer/beams, the roof connection will be via roofextenda brackets holding a 290x45, 2 of 140x45's interconnecting joists/rafters spanning from the house connection to the post bearer/beam, will also framed and housed inside the rendered cement sheet.

 

for roofing, we are waiting for a quote back on a louvred roof system to be recessed in between the structures, this is budget dependant, so an alternative would be to replace the louvred roof system with a colorbond trimdek/steel roof (or similar) rafters & battens with a box gutter.

providing we design/engineer for the worst case roof load, we can build the structure and drop a roof in at another time, the louvred roof supplier has some alternative "off the shelf" systems that could work as an alternative to a louvred roof.

 

apologies for the large post, i thought it would be a good idea to sign up and create a thread at 11pm on a friday.

look forward to the discussions to follow

thanks all.

MitchellMc
Bunnings Team Member
Bunnings Team Member

Re: Introductory Post - 50m2 Deck/Pergola

Welcome to the Bunnings Workshop community @HandyAndy. It's great to have you join us and many thanks for sharing your project.

 

That's a fair amount to digest but I trust our members will appreciate the detail you've gone to in laying out the specifications of the project. This sounds like it will be an amazing build and we can't wait to go on the journey with you.

 

I really don't have anything to add except well done on such a thorough plan and your designs look fantastic.

 

Please let us know if you need any assistance with the project or if you have questions that the community can help with.

 

Mitchell

 

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Jason
Community Manager
Community Manager

Re: Introductory Post - 50m2 Deck/Pergola

Hi @HandyAndy,

 

Just also wanted to extend my own warm welcome to the Bunnings Workshop community. We're so thrilled to have you join us and look forward to seeing you join in lots of discussions across the site. You obviously have a great deal of knowledge and experience to share with our members, and I trust you'll get plenty of helpful information and inspiration in return. 

 

Please let me know if you ever need a hand getting the most from the site, or have any feedback about how we can improve Workshop for you. 

 

Thanks again for introducing yourself and your fantastic project. 

 

Jason

 

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HandyAndy
Building a Reputation

Re: Introductory Post - 50m2 Deck/Pergola

hi all,

 

thanks @MitchellMc & @Jason for the welcome.

 

unfortunately, the boss has canned the pergola idea, due to the columns and where the roof finishes, there is a fair amount of space wasted, so she just wants a plain and simple roof, probably go with a skillion but i might go with something that requires minimal fall.

 

I have also just learned that there is some issues with building a deck/pergola within 900mm of a boundary, can anyone offer some advice here?

 

thanks in advance

Andy

Re: Introductory Post - 50m2 Deck/Pergola

Hi Andy,

 

I believe the code reads "an unroofed deck cannot encroach into the minimum 900mm setback required by the NCC, unless it is provided with some means of fire-resistant construction". However, the code then goes on to say that "a deck is not considered an un-roofed terrace and therefore not permitted as an allowable encroachment". 

 

Depending on your location there might be the option to get a siting relaxation which could require engaging a private certifier to produce a building cert for both the council and the adjoining properties owner.

 

Mitchell

 

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HandyAndy
Building a Reputation

Re: Introductory Post - 50m2 Deck/Pergola

thanks mitchell, so is it as simple as putting a roof over it?

although, I'm tipping a roofed pergola (patio?) would need fire protection if it goes within the 900mm also.

 

it seems there are 2 reasons,

1. a fire issue, with the fence? what's the reason? so if my house catches fire the fence won't and therefore possibly spread to the neighbours house? or vice versa?

 

2. an issue with the neighbour not liking it? a privacy issue? or is it all a fire issue? and the neighbour just needs to be ok with the fence burning down? because in regards to privacy, it wouldn't be much different than me putting a slab there. i don't think the neighbour would mind anyhow.

 

ultimately, are these things i need to discuss with my building surveyor, or things I need to address prior to engaging one?

Re: Introductory Post - 50m2 Deck/Pergola

@HandyAndy,

 

I do not believe it is as simple as just putting a roof over it. If you are encoaching close to a boundary, whether it is a deck or a structure with a roof, I would certainly seek the assistance of a building surveyor.

 

As you have mentioned it seems to be both related to the spread of fire between structures and also a privacy issue.

 

Mitchell

 

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