My decking area 4.4 x 4.5. The height fekm floor to door is 165. I was wondering whether i should go for 140 frame or 90 cm frame
Thanks
Welcome to the Bunnings Workshop community @mimughosh. It's terrific to have you join us, and many thanks for your question about decking frames.Given the height you’ve got to work with, a 90mm frame would be the better option. If you were to use 140mm framing plus 19mm decking boards, that would bring the total thickness to around 159mm, leaving you with only about 6mm clearance between the bottom of the deck and the ground. That’s simply not enough space for drainage and airflow, and poor ventilation is one of the leading causes of early timber decay and premature deck failure. By using 90mm framing instead, you’ll maintain a more suitable gap under the deck for air circulation and moisture to escape, which is crucial for the long-term durability of the structure. Low-level decks need all the airflow they can get, so keeping the frame as slim as possible while still strong enough for the span is the smarter way to go here.
Here's a helpful guide: How to build a low-level deck.Please let me know if you have any questions.Mitchell
Then i would i raise is to make 140-142mm
my board 23mm.
i will need 50 to 52 raise feom concrete/
Can i use treated sleeper blocks under to raise?
whats is the beat option?
thanks
Raising a deck would typically be done with pedestal feet @mimughosh. These Builders Edge 35 - 60mm Smallfoot Pedestal Feet will do the job. As their height is adjustable, they are really handy for levelling your deck.
Mitchell
How many would i need for a 4.5 x4.4.
how about treater sleeper blocks of 50mm??
You would need to support the 90 x 45 mm joists at least every metre with the pedestals @mimughosh, so around four per joist. Along your 4.5m span, you'd have a joist every 450mm, so around eight joists. That's 32 pedestals.
Using blocks of treated Pine sleepers is not a commonly accepted building practice. How long they would last before decaying is somewhat uncertain. Shame to go to the expense and effort of building a deck only for the supports to rot out in several years.
Any other cheaper option available in market?
Not that I am aware of @mimughosh. You could possibly lower costs if you were to excavate the ground under the proposed deck to increase the space and run bearers under the joists. A larger calibre bearer would need to be supported less frequently. However, the reduction in cost for the feet would be somewhat offset by the additional cost of the timber bearers.
