Span Table problems

Hi

There are a hundred threads here for these things (Span Tables) and it has confused the hell out of me

I am building a deck off my house, attached to the weather boards.

It is 3.6 deep and 6 mtrs wide. I am putting 100x100 pine stumps every 1.2 (3 of these make the 3.6) and every 2 mtrs - 4 of these make the 6 mtrs

I am planning to use F7 pine as follows

Bearers: 190x45
Joists: 90x45

Unsure of my wind rating (I plan to add a roof later) but I am in Brisbane and the houses I have built have always been w33.

Do these numbers look right... I really have had some trouble with these damn tables :doh:

Cheers

GMC

So I guess others have the same problems with these tables as me - lol

So does anyone know of a calculator that I can punch these numbers into, to see of they will work

Thanks

GMC

You can go to www.timber.org.au and get theirs, then design it as a floor. Or you can get one of Allan Staine's books, which will also explain the wind ratings. Or you can buy the framing code from Government bookstores.

If no one else responsd I'll try to look in my tables tomorrow.

I pressume when you say pine ... it's all treated?

Quote:

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Originally Posted by OBBob

You can go to www.timber.org.au and get theirs, then design it as a floor. Or you can get one of Allan Staine's books, which will also explain the wind ratings. Or you can buy the framing code from Government bookstores.

If no one else responsd I'll try to look in my tables tomorrow.

I pressume when you say pine ... it's all treated?

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I would expect it to be treated!!!

Thanks for the reply, and I'll have a look at the site above.

GMC

OK ... so you are stuck with me! I'm not a builder so you would be best to get yourself a book that explains the tables, however the posts look OK as long as the deck isn't some huge height off the ground.

I'm not sure from above, which way your bearers run. TP 90 x 45mm joist can span 1700mm continuous span at 450mm crts. (according to Allan Staines).

He doesn't list 190 x 45 as a bearer, that seems very tall and skinny? If I'm reading it correctly :) he suggests 2/170 x 35 to span 2.1m. Happy to send you the table if you want to PM me.

So, I guess you have to decide if you want to spend more on timber or dig more holes!! Hope this helps.

Have a look at the "timber solutions" program at www.timber.org.au.

I gave a quick rundown in how to use it in this link, but if you don't understnad span tables it may be over your head.
https://www.woodworkforums.com/showthread.php?t=55014

Alan Staines book is a good place to start.

OBBob. Did you refer to Alan Staines book? The tables I have from his book only covers spans of 1800, 2400, 3000, 3600

Quote:

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Originally Posted by bpj1968

OBBob. Did you refer to Alan Staines book? The tables I have from his book only covers spans of 1800, 2400, 3000, 3600

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Yeah, I was referring to the 5th editoion of the Deck & Pergolas book. You may be looking at the load widths, the actual spans are across the top of teh table I think. Correct me if I'm wrong!!

Hit the wrong button, But assuming the bearers run the 6 metre length and spaced every 2 m, then 190 x 45 can span 2400, and each bearer can be 1800 apart. But the tabels for joists don't go down to the size of 90 x 45.

Timber solutions gices teh following
Seasoned Pine F7
Bearers. 2/120x45 (just)
an

Hit the wrong button, But assuming the bearers run the 6 metre length and spaced every 2 m, then 190 x 45 can span 2400, and each bearer can be 1800 apart. But the tabels for joists don't go down to the size of 90 x 45.

Timber solutions gices teh following
BEARERS
Seasoned Pine F7
2/120 x 45 (just) good for 2080
2/140 x 35 good for 2140
All others are also 2 per bearer
Unseasoned F 7
125 x 100 (just) good to 2020
150x75 2160
150x100 2430
175x50 2090
175x75 2530

JOISTS


Seasoned Softwood, F7

Single Span Continuous Span
Joist Spacing (mm)
450 500 450 500

90x35 N/A N/A 1340 1310
90x45 1260 1260 1520 1500
120x35 1740 1720 1800 1800
120x45 1800 1800 1800 1800

190*45 spans 2.1 on a deck more than a meter out of the ground - 3m if under one meter out of the ground, with a bearer spacing of 1.2.
90*45 at 450 centres spans 1400 single & 1700 continuous.

The original post was because GMC was confused ... I hope we've helped!! :)

You've confused me! :D

How you doing GMC?

GMC,

For bearers and joists I always use F17. Can use bigger spans without bounce. I either paint them (roller on / paint brush smooth over some Dulux X10 - 2 coats if some members are going to get water) or use Protectadeck plastic capping. It's an extra cost but better that than bounce and compromise. For roof members I use F7 or now as it's known F5 (treated / dry). Can't go wrong.

Cheers,
Dr - 307.

Quote:

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Originally Posted by OBBob

The original post was because GMC was confused ... I hope we've helped!! :)

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Well yes - I think I need to understand the tables before I use the website programs - so that sucks

Thanks everyone for the advice.. I appreciate it

GMC

Quote:

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Originally Posted by ausdesign

190*45 spans 2.1 on a deck more than a meter out of the ground - 3m if under one meter out of the ground, with a bearer spacing of 1.2.
90*45 at 450 centres spans 1400 single & 1700 continuous.

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Ah haaaa

These are the numbers I was looking for

These numbers seem to work for my plan. the 190x45 spans 2.1 and I am looking at 2... and the 90x45 at 450 centres span 1400, and I am only looking at 1.2

So all looks good to me

Thanks ausdesign

GMC

PS I still havent worked out what continuous and single is - but I think I am over it now :D

That's OK GMC.
Single span is when a length of timber is only supported at each end.
Continuous span is when a length of timber is supported at both ends plus is supported (once or several times)along its length.
The tables refer to the different types because a single span is weaker.
The joists in your project could be 3.6 long - they would then be continuous - or you could have 3/1.2 & they would each be a single span.

does anyone have a pdf of span tables that i could download
thanks squ3ak:roll:

Quote:

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Originally Posted by ausdesign

That's OK GMC.
Single span is when a length of timber is only supported at each end.
Continuous span is when a length of timber is supported at both ends plus is supported (once or several times)along its length.
The tables refer to the different types because a single span is weaker.
The joists in your project could be 3.6 long - they would then be continuous - or you could have 3/1.2 & they would each be a single span.

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Thats so simple... thanks

Sometimes we need to look at the obvious, rather than look at it for the complicated

Thanks again ausdesign

GMC