Clueless deckbuilder -help please

Hi everyone,
I've just joined but have been using the forum over the past few months to get advice on my deck building issues, so thanks for all the info provided. Without the forum I would have made a couple of huge mistakes.
I am finally at the timber buying stage. The deck is 8m x 7m . I am in Sydney, the engineer has specified F7 timber, some people are telling me that the joists should be hardwood to nail tighter with the hardwood decking. The deck will be braced, I'm not sure if that affects how it behaves. Is hardwood more susceptible to termites, in one section it will be very close to the ground. What is more durable? For the decking, around here merbau and spotted gum seem to be the most available, which is better?
Any contributions would be greatly appreciated.

I don't know anything about the Sydney area, up here in North Queensland, we use treated pine for the joists and hardwood for the decking.
I think I would listen to the engineer, he probably knows what he is talking about.
Wolffie

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Originally Posted by Lloydbraun

Hi everyone,
I've just joined but have been using the forum over the past few months to get advice on my deck building issues, so thanks for all the info provided. Without the forum I would have made a couple of huge mistakes.
I am finally at the timber buying stage. The deck is 8m x 7m . I am in Sydney, the engineer has specified F7 timber, some people are telling me that the joists should be hardwood to nail tighter with the hardwood decking. The deck will be braced, I'm not sure if that affects how it behaves. Is hardwood more susceptible to termites, in one section it will be very close to the ground. What is more durable? For the decking, around here merbau and spotted gum seem to be the most available, which is better?
Any contributions would be greatly appreciated.

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We also use Trated pine. Rough header treated pine. (rhtp).

Don't use hardwood as it is suseptable to termites and here in vic you have to treat for termites so by using treated pine RHTP (kiln dries treated pine) this is H2 treated which is termite treated. It also rots unless covered with melthoid.
By using f7 RHTP you just have to make sure you span them the wright spans. Sure f17 will span further but depending on the span only means a couple of extra holes.
I doo all of my decks with treated pine but merbau decking. Span the joists at 400mm though.

Regards
JAMC

I'm a bit old school with timber decks and prefer to use hardwood joists, I recon they hold the decking down a bit tighter. Having said that I've just finished a deck using treated pine joists they're certainly a lot easier to work with and cheaper. If you do use pine make sure you get the 65 mm helical twist nails. How much clearance from the ground have you got? I think 150 mm is the minimum.

I prefer to use Austalian hardwood for the decking I think it lasts better and is a bit more ethical than Malaysian rain forest timber.

Thanks a lot guys. I'll go with a treated pine structure as termites are an issue around here. The decking choice will be a tussle between my conscience and budget.

Why is he clueless :?

Use the twist nails to put your decking down too, pre-drill and hammer manually so they twist as you hit, will never some out.

Interesting story, couple of months aqo I had to remove a 3-month old 50m² decking that was made by a halfwit. Imagine too thin joists, twisted wet sawn pine posts set into ground 300mm without concrete (and doubling as handrail posts), 10 framing nails punched into each join, bearers too far apart and decking boards nailed with bends still in them. The deck felt like a trampoline on top!

The owners wasted $7000 getting the guy to do it and then spent another $5000 to replace it with paving and gardens!

These question may show you how clueless I am, Dazzler.
Thanks for the advice.
Do I only pre-drill the decking?
How big should the drill bit be compared to the nail size?

Quote:

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Originally Posted by Lloydbraun

These question may show you how clueless I am, Dazzler.
Thanks for the advice.
Do I only pre-drill the decking?
How big should the drill bit be compared to the nail size?

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Generally, the drill bit used should be around 80% of the size of the screw. For the twist shank nails recommended here, I tend to use a 2.5mm bit for the pilot holes.

I'd build it for you but then i would have to

CHARGE YOU lol

Sorry to break it to your engineer but the timber is no longer F7 its now F5 and the code has been rewritten to suit


Sorry my humour is a little off tonight


cheers utemad

When we built our deck, we predrilled the boards to avoid splitting but drove the nails directly into the treated pine joists. Problem up here in the humidity is, the nails keep working themselves up off the boards so we replace them as we go with stainless decking screws. Expensive but worth it.
Wolffie

Quote:

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Originally Posted by Wolffie

When we built our deck, we predrilled the boards to avoid splitting but drove the nails directly into the treated pine joists. Problem up here in the humidity is, the nails keep working themselves up off the boards so we replace them as we go with stainless decking screws. Expensive but worth it.
Wolffie

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I gather you used 50mm titadecks...

65mm titadecks are both fatter and longer and are better suited to treated joists

Stick with the screws if they are working for you

cheers utemad

H2 treated is for termites but is really only intended for indoor use, but you can get H3 for near the same price, and that is termite and rot 'proofed', but only for above ground, anything that goes into the ground has to be/ should be H5 treated.

Quote:

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Originally Posted by UteMad

I gather you used 50mm titadecks...

65mm titadecks are both fatter and longer and are better suited to treated joists

Stick with the screws if they are working for you

cheers utemad

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We used 90x19 Decking Balau, whatever that is.
Wolffie

Thanks for the great advice. Will definitely go with screws.
Engineers! $1800 to draw the footings for a deck and he didn't know the codes.

Quote:

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Originally Posted by Wolffie

When we built our deck, we predrilled the boards to avoid splitting but drove the nails directly into the treated pine joists. Problem up here in the humidity is, the nails keep working themselves up off the boards so we replace them as we go with stainless decking screws. Expensive but worth it.
Wolffie

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Were they twist shank gal nails :?

I can get smartbits if enough people want them but i will have to buy a box to keep the cost down .. I would do through ebay to keep it safe and simple and estimate a posted cost of $37.50 PM if interested so i can check if there are enough people to cover buying a box

Cheers utemad

The deck is being built on sandstone.
The engineer has specified concrete piers ( 400 x 400 x 300). Where the sandstone is exposed I am considering chemsetting the stirrups to the sandstone.
How would this compare in strength to that of the piers?