Bearers joists span tables etc

[pharmaboy2]

Hello everybody,

have read literally hundreds of posts here, and a pretty common problem is timber sizing etc. Anyway happened upon a very good site that has tables for timber sizes, beams, lintels, rafters etc

http://www.fordtimbers.com.au/dpr_span_tables.htm

also for pine

http://www.designpine.com/designandengineering/spantables.asp

and I've often found CHH pretty useful for beams - light and easy to install

http://www.chhfuturebuild.com/WSMApage/0,1565,18720-1,00.html
designIT software is good.

Saved me buying a table book which last time I looked were a hundred bucks or so. Anyway happy renovating!

[ausdesign]

If anyone wants to know any span sizes etc just let me know through the forum.

[Gaza]

The hardwood that Ford produces is a great product, i can stand by it, beware that if using hardwood from Vic it will not reach aceive the same spans as this stuff.

[Glen Bridger]

Hi Peter,

Here is the drawing with the dimensions.

[Glen Bridger]

Peter,

Here are some photos.

Thanks,


Glen

[readnik]

I could not find on these sites how deep footings should be when building a deck or the like.
Pharmaboy2 or anyone else do you know where i could get this info?
I live in Townsville which has a cyclone rating and i want to build a varandah along the side of the house (shade cloth roof). Could anyone give me some info on footing sizes?


readie

Ps thanks for the other sites they will help with the framing dimensions. I wish i had found this website 5 years ago

[readnik]

Another great website is this for the qld people on the forum

http://www.timberqueensland.com.au/application/diy.asp

readnik :)

[ausdesign]

readnik, the foundation depth is determined from the site soil classification.
if this is unknown or you do not wish to go to the expense of having a soil test done many councils will accept 'founded at depth of existing footings'

The minimum embedment for Class A & S sites is 400mm
Class M 500mm
Class M-D 800mm
Class H 1000mm

The area of deck supported by each post then determines the pad size required.

[readnik]

thanks very much ausdesign much appreciated


I live in an estate in townsville so i am sure the developers would no this soil type so i will hit them up on my next break.

thanks again


readnik

[AshleyM]

Hi Ausdesign

I am looking into doing a deck (when they finish the house that is). Could you possibly give me some help on spans, post sizes etc.

It will be coming straight of the back of the house enclosed in the "Alfresco" area. It will be approx 6m square. I wanted to do the construction from treated pine and deck it with merbau or preferably jarrah if the budget permits.

Any tips would be greatly appreciated.

Ash

[ausdesign]

Greetings Ash.
There are many configurations of bearers & joists that you could use.
For example 140*45 joists could span 3 met, requiring 3 rows of bearers ( one at the house) 2/240*45 bearers will span 3 met requiring 3 stumps along each length.

The Timber Promotion Council victoria have a booklet (used to be around $14) with spans and info on stumps, step materials, posts etc etc - called "Timber Decks design & construction manual" I don't know if this no. is still current 9662 3222.

Alternatively if you send a detailed sketch of the layout and what you want to do I'll look at it but as i said there are many configurations

[Dion N]

Pharmaboy - thanks for the links.

I have had a look at the DPR tables and have a few questions. I am looking a buiding a small shed (3x4m) on a slab with a gable roof. Looking at the tables for 2400mm studs there a several columns I'm not to sure about.

Frame Size (75 or 100mm) - I assume that this is the depth of the wall frame?

Roof Span in mm - is this the span along the wall frame (ie the length of the frame) or is it the roof span perpendicular to the wall frame (ie the distance between the two frames spanned by the rafters/truss)?

I also have a question re timber grading - I have access to recycled hardwood 50mm x 75mm - what stress grade should I use? It is well seasoned! I was thinking F11 or F14?

[Terrian]

Well, the house is just about paid off (10 years into the 25 year loan :) and she who must be obeyed wishes to extend.

Currently a 3 bedroom timber home, steel roof.

What we would like to do is add (to the rear of the house) 2 bedrooms, and a toilet, convert the existing bathroom to an ensuite and one of the existing bedrooms to the new bathroom.

The fall of the land would allow an additional room under where the wanted extention would be.

What I woud like is to have is a wall free area of approx 6m x 5m (7m x 6m would be nicer :) for use of whatever I want (games room, home theatre, garage, workshop, bar, whatever :)

Suggestions to accomplish this ?
Steel beams perhaps to support joists ?

All suggestions accepted :)

cya

[ThePope]

Frame Size (75 or 100mm) - I assume that this is the depth of the wall frame? Yes


Roof Span in mm - is this the span along the wall frame (ie the length of the frame) or is it the roof span perpendicular to the wall frame (ie the distance between the two frames spanned by the rafters/truss)? Span is overall measurement of the wall frame, usually the shortest run. In your case it would be 3m.
http://www.josephfusco.org/Articles/Roof_Cutting/raftercutting.htm#What%20is%20the%20span%20of%20the


I also have a question re timber grading - I have access to recycled hardwood 50mm x 75mm - what stress grade should I use? It is well seasoned! I was thinking F11 or F14? Your 75*50 Hwd will be fine, no need to worry about what grade it is.
Only worry you'll have with it is how to get a nail through it :)

[ThePope]

What I woud like is to have is a wall free area of approx 6m x 5m (7m x 6m would be nicer :) for use of whatever I want (games room, home theatre, garage, workshop, bar, whatever :)

Suggestions to accomplish this ?
Steel beams perhaps to support joists ?

Running a steel UB down the centre of the room to carry the joists is usually the cheapest option.

[Dion N]

Yes

Span is overall measurement of the wall frame, usually the shortest run. In your case it would be 3m.
http://www.josephfusco.org/Articles/Roof_Cutting/raftercutting.htm#What%20is%20the%20span%20of%20the

Your 75*50 Hwd will be fine, no need to worry about what grade it is.
Only worry you'll have with it is how to get a nail through it :)

Thanks - I guess the drill will be getting a workout, although at $1.50 per length (min 3m ) the hwd is too good to pass up.

[pharmaboy2]

What I woud like is to have is a wall free area of approx 6m x 5m (7m x 6m would be nicer :) for use of whatever I want (games room, home theatre, garage, workshop, bar, whatever :)

Suggestions to accomplish this ?
Steel beams perhaps to support joists ?

All suggestions accepted :)

cya

Another option apart from the steel, is to use the hyspan beams, and use joist hangers so that you dont have to deal with the beam in the downstairs room when you go to line it (can do this with steel as well, but its a little trickier with connections).

Check out the cost comparisons, because I'd just spend the extra money and get the manufactured joists that will span the full distance - probably at 300 centres or therebouts, you can certainly span 6m using only 350 depth, which is neat easy, check the cch site out for it.

[AshleyM]

Hi Peter
I have a copy of my plan with the decking area sketched in. How can I get this to you? Could you send me a pm with an email address?
Regards
Ash

[Dion N]

For those interested in Span tables, check out the free programs available from Hyne Timber (Design in Hyne) and Carter Harvey Holt (DesignIT). I found DesignIT to be user friendly and you can deisgn in a range of soft and hardwoods as well as their engineered products such as Hyspan LVL and Hybeam. It was 39mb to download (including Microsoft .NET program), 17Mb if you already have .Net

You can order the programs on a CD if your connection is slow. I still downloaded the program using dialup whilst I watched a DVD!:rolleyes:

[jewelsandrew]

If anyone wants to know any span sizes etc just let me know through the forum.

Hi Peter,

I am building a 5m wide deck out the back of my house by 7.6m long (the 5m width is perpendicular to my house slab/wall. I propose to use treated pine size 140*45 for the bearers and joists. According to the new tables and technical note 1, I can get away with spans of 2.2m for F5 (single span) and 2.3m for F7 single span. i sthis correct!

or 2.6m for F5 (continous span) and 2.8m for F7 (continous span)!

I am approx 0.5m above ground and propose to bolt a waling plate size 140*45 to my house slab/wall which the bearers can be connected to, the next support will be 2.250 meters away and then another set of supports 2.250m away follwed by a 500mm cantilever. The joists will then be at 450mm centres. For the supports I am looking to use a 300mm concrete foundation formed by using a 300m pipe as a sleeve.

Are the timber sizes I proposed okay for both the bearers and the joists?and is this a single span or continous because the first connection is bolted to the waling plate. any comments would be greatly appreciated.

[jewelsandrew]

I am building a 5m wide deck out the back of my house by 7.6m long (the 5m width is perpendicular to my house slab/wall. I propose to use treated pine size 140*45 for the bearers and joists. According to the new tables and technical note 1, I can get away with spans of 2.2m for F5 (single span) and 2.3m for F7 single span. i sthis correct!

or 2.6m for F5 (continous span) and 2.8m for F7 (continous span)!

I am approx 0.5m above ground and propose to bolt a waling plate size 140*45 to my house slab/wall which the bearers can be connected to, the next support will be 2.250 meters away and then another set of supports 2.250m away follwed by a 500mm cantilever. The joists will then be at 450mm centres. For the supports I am looking to use a 300mm concrete foundation formed by using a 300m pipe as a sleeve.

Are the timber sizes I proposed okay for both the bearers and the joists?and is this a single span or continous because the first connection is bolted to the waling plate. any comments would be greatly appreciated.

[me3_neuralfibre]

Greetings Ash.
There are many configurations of bearers & joists that you could use.
For example 140*45 joists could span 3 met, requiring 3 rows of bearers ( one at the house) 2/240*45 bearers will span 3 met requiring 3 stumps along each length.

The Timber Promotion Council victoria have a booklet (used to be around $14) with spans and info on stumps, step materials, posts etc etc - called "Timber Decks design & construction manual" I don't know if this no. is still current 9662 3222.

Alternatively if you send a detailed sketch of the layout and what you want to do I'll look at it but as i said there are many configurations

I thought those books got canned when they amalgamated to the 2006 AS for timber.
I bought a copy of the standard and have all the spans etc. What I can't find is useable information on what diagonal bracing is requried in the legs. The deck will be on a high set qld house, wrapped around one corner (L shaped). It's basically a 10X13L that is 4.5m deep. Any suggestions appreciated. I want to minimise the diagonal bracing on the legs.

Thanx
Paul

[echnidna]

DesignIt is available here (http://www.timberbuilt.com.au/software/designit/index.html) as a free download

[pawnhead]

That looks like a handy tool. I'd imagine that engineers wouldn't be too happy about it.

[chessp]

You may be regretting ever saying those imortal words of anybody needing any help....

I really would appreciate some guidance - I bought the Allan Staines book on decks and pergolas and the book contains the spanning tables however I must be losing the plot as I cannot make heads or tails about what he is talking about.

The top column is the size of bearers for bearer span. This gives you distances from 1200-3000 (I am assuming that this is the maximum distance of the piece of timber from start to finish). Please tell me if I am wrong. The vertical column to the left of the table denotes the "Load Width" - whats this all about? Is it the maximum gap between posts allowed? Likewise if you have a value for instance 2/120*45 I am assuming this requires 2 pieces of timber either side of the post?

I really could do with somebody telling me the following based on my attached drawing of how I want to lay my deck out:


How far apart do my posts need to be from each other?
What size ledger do I need to secure to the wall to rest my joists on to?
What size bearer timber do I need?
What size joist timber do I need to span 5.4m?

If nobody can tell me answers to this question maybe they can give me an idiots guide on how to work the tables so as I can calculate myself? Any assistance would really be appreciated.

[silentC]

Span is the distance that the bearer must span - ie the distance between posts or other supports. It's usually given as two sets of figures: single span where the bearer spans only two posts - it is supported only at the ends; and continuous span in which the bearer spans at least three posts or supports.

Without having the table in front of me, I can only assume that by Load Width he is referring to the spacing of the bearers - which in turn gives the span of the joists. The wider the spacing, the heavier the bearers need to be because each is carrying proportionally more weight.

How far apart your posts need to be is a factor of the bearer size you select. The full length of the bearer is immaterial in this because using the continuous span sizes, you could theoretically make a deck of infinite width, as long as individual spans between posts were within the specified distance. Likewise for joists. You select the joist to suit your bearer spacing. The closer the bearer spacing, the lighter the joist required.