Low-level deck building advice needed

Hi team,

Newbie here - looking to build my first backyard deck.

It is a difficult area, there is an oddly shaped brick area that needs to be covered and extended out on to the lawn. I want the deck to cover from when you exit the door, to a few meters over the lawn area. Please see photos attached.

I need advice for:

- what footings and timber width I would use for the base structure over the bricks.

- what footings I would need for the lawn area - I imagine I would need to put cement weight bearing points in to the grass area.

- any advice for navigating the drain area - I want to keep that where it is, so I think it would be possible for that portion of the deck to be a lid that can be lifted out?

Thank you in advance.

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Comments

MitchellMc

Welcome to the Bunnings Workshop community @TrentW. It's marvellous to have you join us and many thanks for your question about building a deck.

You should find this guide useful: How to build a low-level deck. You might also like to read through some of the deck projects our members have contributed.

Unless you are planning on stepping out the door and up onto a deck, there doesn't appear to be much room to construct the deck on top of the bricks. What's the height from the bricks to the doorsill? This is the height you have to work within and will affect the size of timber you can use to construct the frame. If you can let me know the working height I can suggest some timber selection options.

On the lawn, you could concrete in post anchors or perhaps look at using the TuffBlock 300 x 300 x 90mm Instant Foundation System Deck Support.

For the drain section, you can frame around it and nail the decking off around its perimeter. A removable lid can then be fashioned to cover the area.

I'm keen to hear more about your project and provide further assistance. Please let me know the height from bricks to door sill and I can suggest what timber you can use.

Mitchell

TrentW

https://www.workshop.bunnings.com.au/discussion/comment/17459#Comment_17459

Hey Mitchell,

Thank you for your prompt reply.

The cement step down under the white screen door is 100 MM drop to the brick - the other cement step down under the white wooden door is 150 MM drop to the bricks. Would it be possible to pull up a row of the bricks along that wall facade to assist with achieving greater depth to work with?

For the TuffBlock foundation, would this be placed straight on to the lawn? Would this hold up for a long down or would the softer soil potentially sag for example? For longevity would cement be more appropriate?

Thank you mate,

Trent.

MitchellMc

https://www.workshop.bunnings.com.au/discussion/comment/71349#Comment_71349

Hi @TrentW,

Unfortunately, the working height needs to be established across the whole deck and not just at the door's threshold. Since there's not enough room to place a 90 x 45mm timber and 19mm decking board in that 100mm height, you'd need to consider placing your joists on their side. This would mean more supports are required over their length. With the joists on their 90mm face, that will be 64mm with decking. That leaves 36mm for a support on the bricks. I'd suggest Builders Edge 35 - 60mm Smallfoot Pedestal Feet. They can also be used on the grassed area if you lay some compacted gravel and place a paver where the feet need to go.

With either the pedestal feet or Tuffblock, you'd need to excavate 100mm of soil, replace 50mm with crushed compacted gravel and the other 50mm with a paver. This will stop the supports from subsiding and sagging.

Mitchell

TrentW

https://www.workshop.bunnings.com.au/discussion/comment/98918#Comment_98918

Hi Mitchell,

Okay brilliant, thank you - if I run into any snags I will get in touch.

I will provide an update in here as I progress also.

Thanks mate,

Trent.

TrentW

https://www.workshop.bunnings.com.au/discussion/comment/98918#Comment_98918

Hi @MitchellMc

Just an update on this post.

I have ripped up half the bricks - I will follow your original advice using the height and pedestal feet instructions. However, to save costs I will then dig holes and concrete in posts and complete the job this way - as height will not restrict that half of the deck, ultimately less materials will be required as I can use stronger timber etc.

I have uploaded new photos - could you please answer a couple questions. I would like to add a patio/pergola over the deck;

- If attaching to the existing fascia, how could this be achieved? My worries are that the gutter system would need to be moved, and the overall height of the roof over the deck would not be sufficient.

- If building a standalone roof, am I able to go higher than the fascia in the photo or am I restricted to being the same height? My understanding is that I can go higher than that fascia, but not higher than the highest fascia on the entire roof? Or higher than 3 metres in general? See the link https://hv.com.au/how-to-get-nsw-council-approval-for-your-patio-pergola-or-deck/

Thank you in advance.

MitchellMc

https://www.workshop.bunnings.com.au/discussion/comment/116411#Comment_116411

It's great to hear from you @TrentW, and I'm pleased to see you've commenced work on your project.

The eave setup you have there is a little unique with the exposed beams, but that might work in your favour as they are easily accessible. The fascia is to hang the gutter off and is not a structural member for connecting structures to. You'll be attaching to the house beams.

The first step is to contact your local council and source information to assist you with this build. For an attached pergola with a solid roof, I suspect there will be several restrictions and rules that you must adhere to. I wouldn't necessarily bet that your build will be exempt from needing approval. Please contact them as each council has varying rules, and it's best to find out the specifics in your location.

Regarding how to connect your new structure to the house, you might be best consulting a qualified engineer as building codes can be pretty challenging to follow. They'd also need to assess whether those beams and the wall's framing are up to the task.

If you were to build a freestanding pergola, you should find this step-by-step guide useful: How to build a pergola frame. Once again, your local council is the place to get the correct information on how high you can build, where you can build, what type of drainage needs to be employed, what type of roofing is allowed and whether you are allowed to build a pergola at all. Some councils won't even allow you to build a pergola that's larger than a couple of square meters if it has a solid roof.

Mitchell

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