Help with Deck Plans

[Needsy]

Hi all. First of all can I say I am new to this forum but the information here is fantastic!!

I have searched for an answer to questions to my decking query but failed to find anything so here goes.

I am looking to build a deck 4.8m x 3.5m (no roof) with a height of 300mm. I looked at the bearer and joist tables but I think I am confusing myself. My queries are:-
1) Could I use the metal post bases to hold my bearers (say 100x100) rather than timber stumps??

2) What spacings would I need on the bearers - could I space them 1750 apart??

3) I am fixing direct to masonry on the house, is it best to dynabolt a bearer to the masonry face to sit the joist on?

4) What size joists would I need (at 450mm spacings)?

5) Could the joists be fixed in line with the bearers using joist hangers (rather than on top)??

Hoping you can help me??

Thanks:)

[Eastie]

Have a look at this link. In relation to steel posts they'd be more suitable than timber so long as they're galvanised.

http://www.timberqueensland.com.au/application/free_pubs/tds04%20residential%20timber%20decks.pdf

[pharmaboy2]

1) Yes
2) Yes - depends on size
3) your choice - although with only 300mm clearance termite inspection may be difficult - I'd leave them separate with a 10mm gap between house and end deck board, (parallel i assume) - some people screw last decking timber down to enable inspection - this is if there is contact between the timber and house timber, if you are below house frame, then you can connect direct.
4) depends on span
5) Yes - preferable given your low clearance of 300mm

for the unanswered, go to search bar at top of page, type in "span tables"
- and Bob will be your uncle.

cheers

[Needsy]

Thanks for the info guys!!

Still a litle confused - If my bearers are 1750 apart and then fixed to the house at 1750 spacing - wouldn't the span on my joists be 1750 continuous??

Also How do I calculate FLW???

Thanks once again

[barrysumpter]

I spent quite a bit of time building mine and posting my progress here.

Took a course at tafe.

And had to get the teacher (long time contractor) to sort the tables out for me.

The tables I remember seemed much harder to read than the ones posted by eastie above.

We build from the bottom up.
But have to design from the top down.

You'll need to decide which decking you are going to use.
Jara/Meribau are hardwood and need less support than the soft wood treated pine to keep them from sagging.

i.e. less support meaning the joists span can be greater.

Again depending on the type of wood your joists are made of the bearers are set to a standad to keep them from sagging or giving slightly under weight.

etc....

Following the standards makes a deck feel like its made as solid as a rock.



Some older homes have a second story veranda that were built using a more leaniant standard or simply made - not following the standard.

I get the willies walking out on a second story deck that sags or has the decking set too far apart.

The Timber Counsel of Australia supplied the current reference book of standards.

My Tait Home Hardware timber specialist was happy to give heaps of advice from designing a simple square deck to finilizing the details on the octagon deck I ended up building.

He also allowed me to hand select each and every piece.

There was also a decking booklett from better homes and gardens (I think) that had the most relivant info on the octagon deck.

Anyway, all the best,

[ThePope]

Based on the assumption you're running bearers the long way (4.8m)

Attach 100*50 Hwd or 90*45 Treated Pine to brickwork, dynabolt say every 1200mm

Run a bearer down the centre of deck spaced at 1750, metal post base at each end of bearer and two evenly spaced in the middle (1600mm). Same again for your outside bearer at 3.5m. You could use either 100*75 Hardwood or 90*90 Treated Pine.

Joist size needed for a 1750 span you'll need 100*50 Hardwood. If you wanted to use 90*45 Treated Pine you'd have to add another bearer to reduce that joist span. Max joist spacing 450mm.

And if you need to keep the the top of joists in line with top of bearers utilising metal joist hangers as you mention that's fine. Just slightly more work and cost.

As I love the longevity of treated pine, I'd be using that extra bearer and using treated pine throughout.