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Low-level deck over concreate with picture framing

Finding My Feet

Low-level deck over concreate with picture framing

Hello Bunnings Family,


If I can do it any one can do it :smile: 


I have been always thinking about deck in my patio. After looking at multiple projects at Bunnings workshop community and the amount of support community offers I have gained confidence in build one on my own. 


My project is close to the dimensions of this awesome build Low-level deck with picture framing | Bunnings Workshop community


Here are the current pictures. Please note that I am planning to extend the deck beyond the concrete slab towards the fence.

WhatsApp Image 2021-09-18 at 6.47.54 PM - Copy.jpegWhatsApp Image 2021-09-18 at 6.47.54 PM (1).jpegWhatsApp Image 2021-09-18 at 6.47.53 PM.jpeg

In the above picture there is a clearance of 11.5 cm only at the entrance of the sliding door.


I need some help in materials and quantity that I need. Below some R&D for the materials selected


1. Merbau 90 x 19mm (SpecRite 90 x 19mm 5.7m Pre-Oiled Merbau FJ Decking - Bunnings Australia)

2. Timber H3 treated 90 x 35mm(Please correct me if I am wrong)

3. Angle brackets (Zenith 50mm Zinc Plated Angle Bracket - 12 Pack - Bunnings Australia)

4. DEKO 250 x 150 x 150mm Instant Concrete Foundation Block(DEKO 250 x 150 x 150mm Instant Concrete Foundation Block - Bunnings Australia) where the deck would be extended on the ground

5. Screws - Please Suggest

6. Deck lights 

7. Not sure anything else required. 


I hope to get a feedback from the experts here. Thanks in advance. 

Bunnings Team Member
Bunnings Team Member

Re: Low-level deck over concreate with picture framing

Welcome to the Bunnings Workshop community @Divakarz. It's sensational that you've joined us, and many thanks for your question on deck construction.


You'll need to draw up a plan of your deck before you get started. This will include various elements like how many joists you'll be using and how they'll be supported. 


The first issue you'll need to address is the minimal space you have to build your deck within. From your 115mm, you can remove 19mm for the decking boards straight away. That leaves you with 91mm for your joists. If you were to use 90 x 35mm H3 MGP 10 Treated Pine Outdoor Timber Framing on edge, that would leave 1mm of clearance under it. It will be virtually sitting on the concrete slab with no airflow and no way for water to drain. You should expect the lifespan of the deck to be reduced due to this. Alternatively, you could lay the timber on its 90mm face. That would then give you a 56mm gap under it.


Joists should be placed approximately 450mm apart across the span. The direction you wish to lay the decking boards will determine the number of joists used. The number of angle brackets and foundation blocks is directly related to the number of joists.


To calculate the amount of decking you'll need, you should find this calculator from Specrite useful. You should need approximately 227 lineal meters of decking and 1044 screws.


My recommendation for the screws would be self-drilling stainless steel. They'll save you a tonne of time by not having to pre-drill and countersink every screw hole.


If you haven't already read through it, check out @Adam_W's article on How to build a low-level deck.


Please let me know if you have any questions.




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Re: Low-level deck over concreate with picture framing

Thanks for your time in providing the detailed @MitchellMc . I shall prepare the measurements and post the details. I am doing it slowly as I can only spend time over weekends. 


I am planning to use these Ramset 10 x 100mm Countersunk DynaBolt Plus Masonry Anchor bolts for attaching brackets to the concrete slab. 






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