How to build a two-level deck?

[evisbal]

Hi Workshop Community.

I got a two-level deck + roof application council approved but I'm not sure how I'm going to build it.

The upper deck area covers the interior of the little porch, connecting on the second step of the concrete stairs [red line]. The questions I have are:

1. how could I make the deck match the second concrete step in the porch [red line]?

2. should I screw the ledger on the wall in the porch or just put stirrups and bearer over the concrete?

3. Would the the outer concrete area resistant enough to install stirrups?

These are the approved plans.

Any recommendation would be highly appreciated. Let me know if you need more details. 

[Akanksha]

A warm welcome to the Bunnings Workshop community, @evisbal. We're delighted to have you join us and hope you find our site a handy resource containing useful D.I.Y. advice and inspiring ideas for your home and garden projects. 

Thanks for your question. Sounds like an exciting project. I'm sure our resident Bunnings D.I.Y. expert @EricL will be able to assist you when he's back online on the site later today. Let me also tag @Itai, who shared this three-tier deck and pergola, along with @diy_hausdesigns, who built a multi-level wooden deck in his backyard, to see if they have thoughts. 

While waiting, you might like to read through experienced renovator @Adam_W's guide on How to build a low-level deck and How to build a deck by D.I.Y. expert @MitchellMc in case they help. You can also check out our Top 10 most popular decking projects if you're after some project inspiration.

Please do keep us updated as your project progresses. We'd love to see the final result.

Akanksha

[Itai]

Hi @evisbal 

For the roof area, the posts that attach to the roof need to be secured with a stirrups concreted into the ground properly. The Existing concrete isn't strong enough. If memory serves me correctly from my build, the concrete hole needs to be 6-700mm deep and 3-400mm wide and filled in entirely with concrete, with a stirrup inset into it, for each post.

To attach the roof to the house, you can't simply connect it to the bricks as that's a veneer (unless your home is a double brick home and not veneer). Same with the ledger for the deck. In both scenarios, they should be attached to the wooden structure within the house itself. I'm not a builder, so can't confirm the appropriate joining method for you.

For mine, I used 250mm landcscape screws to attach the ledger to the wood of the house by going through the brick, but not attaching to the brick. (I also went through a copper pipe, so watchout for anything inside the walls!) For my roof, I attached to the roof structure using Roof Extenda brackets, but that won't work in your scenario. You might be able to remove the eve of your porche and put through bolts through the wood beam there. But you need to confirm the strength and if it's appropriate.

For getting it level with the step over the concrete, you can simply use L brackets and appropriate height wood for that portion to get the heigh you want. Thinner wood, need more L brackets.

Regards

Itai

[EricL]

Hello @evisbal 

Thanks for sharing your question about your two-level deck. It's great that you've received very good advice from @Itai. Just to add to the suggestions made, I recommend studying your plan and breaking it down into sections. For example, I suggest assembling the frame of the upper deck first. Your plan should indicate how high the frame should be and what kind of footings you'll be using for that area.

A good example of an adjustable footing is Builders Edge 70 - 170mm Bigfoot Xl Pedestal Feet. Combined with the timber you'll be using you can adjust it incrementally so that you can have it perfectly level with the second step. 

@Itai brings up a very good point, is your brick wall real bricks or is it faux bricks rendered over a concrete wall. This is something you'll need to find out before you make any plans about anchoring into the wall. Please keep in mind that brick walls are great at holding vertical weight, but not so good at horizontal stress.

I suggest having a quick look at these guides - How to build a low-level deck by @Adam_W and How to build a deck by @MitchellMc. These guides will give you a good idea what to take into consideration when building your decking frame. 

Here are some excellent multi-level decks our Workshop members have shared:

• Three-tier deck and pergola by @Itai
   
• Low-level deck and pergola by @jase2 

If you have any other questions we can help with, please let us know.

Eric

[evisbal]

Thanks for the reply, Eric.

I'll done some research, and after taking some more measurements, I've build two options for the upper deck. The main difference is the number of posts for the bearers. Furthermore, the bearer in yellow would initially be attached to the brick wall, however, I'm also considering putting another line of Builders Edge 70 - 170mm Bigfoot Xl Pedestal Feet. along with the existing one [dotted circles], because there are some cracks in the wall and I'm not sure if putting dynabolts will damage it more. Would it be an acceptable solution as well?

A couple of more questions:

- Which should be the posts for the roof?. Should I put extra or can I use the exterior ones???

- What's better, more posts supporting the bearer and lighter timber or longer spans and thicker timber?

- What's the best method to attach the posts to the bearers if they will also be used for the roof?

- I've found different span tables for treated pine, where can I find the most reliable one? I live in Tasmania.

Thanks. I hope everything makes sense. Let me know if you require more details.

[EricL]

Hello @evisbal 

In regards to the bearer in yellow have you thought about using angle brackets to anchor it to the floor or perhaps use an anchor post in combination with a timber footing. 

What timber size will you be using for the frame of the deck? Will you be constructing this as a standard frame or single level frame? In regards to the post, its size is based on the load that will be applied to it, that includes the decking frame, beams and rafters of the roof.

As to what's better, more posts supporting the bearer and lighter timber or longer spans and thicker timber? You could start a whole new discussion regarding this topic. I suppose it depends on the circumstances and size of the deck. 

The most commonly used anchor is a nut and bolt assembly. I'll have to make some inquiries regarding span tables. As soon as I have more information, I'll get back to you.

If you need further assistance, please let me know.

Eric

[EricL]

Hello @evisbal 

Thanks for your patience. In regards to the span table, it's best to request them from the manufacturer of the timber you'll be purchasing. Here are the span tables from our supplier Hyne for their timber.

If you need further assistance, please let us know.

Eric

[evisbal]

Hi again, I'm close to start this project but I have another question related to the roof, which I decided will be detached, mostly because I don't want to damage the existing hardiplank when looking for structural framing to fix the ledger.

The back posts will be sitting on the existing concreted area in the small porch but the right-hand side one will be shorter as it will be on the concrete stairs. Do you see any problem with this idea? Thanks.!

[MitchellMc]

Hi @evisbal,

My only concern would be whether fixing to the edge of a concrete staircase would provide the same structural support as a concrete slab or footer, which you'd typically be using. There are some unknowns going on, like whether this is a poured concrete staircase, or is it hollow in portions, or perhaps it's bricked with a concrete render. The only person who will be able to answer your question definitively is an engineer.

Please let me know if you have questions.

Mitchell