How to build low-level decking with Tuff Block?

njblackah

Hello,

I am wanting to build a decking 5 x 3 about 1m back from my pool edge. The deck will be a lounge area and will never have more than 2-3 people sitting on it. Do avoid having to dig around pool plumbing and electrical, i am hoping to build a low profile deck using the following method. The deck will be in full sun/weather

1. single layer sub-frame using 90x 45mm H3 pine spaced 450mm

2. tuff blocks every 900m sitting on level compacted gravel

3. noggins spaced every 600mm

4. perimeter  joists fixed to brick wall behind and concrete pool edge with galvanized dynabolts

5. under surface and ends of the joists painted with bitumen paint

6. top surface of the joists covered in deck tape

7. 100mm opening at either end to allow some ventilation 

My concerns are the following

1. will it be strong enough using 90x45mm? It will be low traffic and will just has two lounge chairs and some pot plants. I could use 120x45mm if this is recommended.

2. Is it to low to the ground to use H3? I am struggling to fine H4 in the lengths that i need to run a continuous 5m joist

any help would be highly appreciated

thanks,

nic

MitchellMc

Welcome to the Bunnings Workshop community @njblackah. It's amazing to have you join us, and many thanks for your question about decking.

What you've suggested complies with standard deck construction techniques and your joist spacing and Tuffblock supports are spaced adequately.

H3 is suitable for above ground use. As long as it's not touching the ground it should be fine. Adding the gravel underneath is a great idea. Just ensure that if the area typically pools water you provide a gradient for it to escape out from under the deck. A decks worst enemy is lack of airflow underneath and pooled water, which creates a humid environment that enables decay.

You might like to take a look at this guide: How to build a deck. It shows a very similar build as to what you intend. 

Please let me know if you have any questions.

Mitchell