Reasons for the relative costs of oak?

[opener]

I've been puzzling over this since I changed the material for my current job from kilned oak to air-dried as mentioned in a previous thread (garage doors).

I normally buy kilned oak as square edged which is fairly easy to convert to the sizes required.
Air-dried comes in large waney edged boards which take a lot of time and effort to cut up.

Say that 1" kd sq edged oak costs £1000 and you allow for 40% wastage = £1400 cu m.
Say that 1" ad waney edged oak costs £900 and you allow for 100% wastage = £1800 cu m

So air-dried costs £400 per cube more than kilned plus hours of extra labour although you do get a large pile of very expensive firewood.

There is also a similar price ratio between KILNED square edged and KILNED waney edged so why would anyone choose the waney edged???

As for AIR-DRIED there was no choice - only waney edged available.

Can anyone enlighten me / add their comments

Cheers
Malcolm

 

[steve tighe]

Something to do with imports.

Generally non European imports (apart from softwoods) have to come in as square edged timber.

European hardwoods usually come in as waney edged,some mills will send out square edged stuff (German mills sometimes send out beech like this),why they're allowed I don't know (more likely forgotten) but I can find out if you like.

I wouldn't go for 100% wastage on European timbers,I'd go 300% to cover my buttocks taking into account what you'd lose on length as well as width,especially on the wider boards where the the mills have dogged the ends to stop further splitting.

Also,if you're specifically talking about using oak for external joinery then AWO isn't an option,it's not an external timber,you should be using European (similar to English,but the grain has a different accent) oak,which unfortunately always comes in with the bark on.

 

[Chris Knight]

There's also something wrong with your maths!

100% wastage mean that everything goes to waste. If you need to buy twice as much wood as you will get usable boards out of it - that's 50% wastage.

 

[Anonymous]

I wouldn't go for 100% wastage on European timbers,I'd go 300% .

300%??

Throw away three times as much timber as you purchased?

 

[Sgian Dubh]

...if you're specifically talking about using oak for external joinery then AWO isn't an option,it's not an external timber,you should be using European ...which unfortunately always comes in with the bark on.

Neither statement is quite correct as far as I know steve.

American white oaks, eg, Quercus alba, are durable for exterior locations. Their structure is very similar to the European oaks most commonly used in similar situations, ie, Quercus robur and Quercus petraea (sp?). Some authorities consider these European oaks as being a form of white oak, eg, probably Gene Wengert.

European oaks aren't always sold waney edged. I understand that a substantial proportion is sold square edged, particularly the material that is exported to the far east and north America. I don't have the exact numbers, but somewhere in my researches on timbers I did come across a figure sometime in the last year or so. Square edged timber saves space and reduces the chance of bugs being exported to other countries along with the wood. Slainte.

Edit. PS. I wondered if, after I'd posted, that you were referring to the American red oaks as non-durable for exterior locations, eg, Quercus rubra? Unlike the white oaks and European oaks I've mentioned, red oaks don't form tyloses. In part, it's the tyloses that confer durability, and they certainly make the white oaks and a number of the Europan oaks suitable for cooperage work.

 

[yfs1]

I wouldn't go for 100% wastage on European timbers,I'd go 300% .

300%??

Throw away three times as much timber as you purchased?

Maybe European Oak has termites so for every length you bring home, they eat two other lengths you had in storage

 

[beech1948]

Opener,

Could I suggest that you use real world prices instead of your made up ones. I am using prices I have paid in the past 3 months at a local yard/sawyer with only air dried oak ( 2 yrs) and a depot/shop/yard with KD oak.

eg. 1" square edge KD Oak at say £40 per cube so if your using say 10 cubes the cost is £400.

1.25" air dried waney edge oak ( to end up with 1" thick finished pieces) at say £23 per cube with 50% wasteage will yieled a price per cube of £34.50 so for 10 cube the costs is £345.

In general if I were to then add in the costs of transpost, my time to go inspect and buy, dimensioning, wood preparation, drying time of air dried the real costs would probably be in the region of £600 for 10 cube.

What kills the air dried choice is the cost of wasteage at 50%. This is a maximum number and most people would probably be able to get by with about 12% to 15% to 25% wasteage.

In this case the prices would be £23 + 25% waste = £28.75 x 10 cube = £287.50.

As a hobbyist I don't charge for my time but obviously for a pro the time issue is paramount. So as a hobbyist I would save about £120 ish by buying air dried on 10 cube.

A way to control wasteage is to take a piece of chalk with you to the woodyard (+ a sharp block plane + some spit to wet the wood to see grain etc) and to measure out the rough sizes of the pieces you want on the boards you select. This enables you to have a clear view of what the costs are as well as some certainty of what pieces will be obtained. I use this to discuss with woodyard owners about shakes, cracks, splits, knots etc etc. Usually with a bit of banter and a bit of give and take, a lot of thank you's, remembering to comment on the yardmans favourite footy team I can get a moderately good deal.

regards
alan

 

[Pete W]

Could I suggest that you use real world prices instead of your made up ones.

Opener's using cubic metres; you're using cubic feet. Makes a big difference :wink:

 

[beech1948]

Pet W,
Don't make much difference Pete the savings just larger. Its not the volume of wood but the prices he used and the assumptions on waste %...........

I cubic meter = 35.314 cubic feet.

so 1" KD at £40 cube ft = £1412.26

1.12" inch air dried sawn at £23 cube ft + 25% wasteage=£28.75 so 1 cubic metre =£1015.27

Saving of airdried is at least £397.

If you have only 15% waste then saving becomes £478.21. So if you were lucky you might save £500 if your an amateur who does not need to charge for time.

regards
Alan

 

[beech1948]

Opener,
I just reralised I made a slight error in nmy calcs. I forgot to add on wasteage for your KD Oak. Its been a bummer today so I'm afraid tireness got to me.

If you add in say 25% to KD as well your saving is most of the way to £600 ( guess I'm too lazy to do this calc again) for a cubic.
regards
alan meter

 

[steve tighe]

There's also something wrong with your maths!

100% wastage mean that everything goes to waste. If you need to buy twice as much wood as you will get usable boards out of it - that's 50% wastage.

Wrong

I wouldn't go for 100% wastage on European timbers,I'd go 300% .

300%??

Throw away three times as much timber as you purchased?

Wrong as well,but you're on the right track.


First lesson learn't,don't post on here after you've just come in from the pub if you can't explain yourself properly.



Pricing up a job you're allowed wastage on the timber,standard practice,you don't know what boards are coming in as you've either asked for a cubic foot amount or sent over a cutting list that you need to get the components out of,it's down to the yard boys to get it out as close as possible.Atkins & Cripps were normally pretty good at this but you pay top money if you go this way,but it usually saves you money overall.

American hardwoods,standard practice is to allow 30% wastage,but you've got to take into account the finished size of what you want.

Example:- 32 X 95mm finish dado (Ex 1 1/2 X 4" ) in AWO,most merchants offer this timber in 6" or wider boards,that's at least 50% straightaway,if your lucky you'll get reasonably straight boards at 9 1/2" to 10" wide,that's a wastage of up to 25%,you've made money on the timber,on the other hand if you get a selection of boards between 6 to 7" wide then that's potentially a wastage of up to 75%,you've lost money on the timber.It's the amount of timber you've got left after you've got the piece you wanted out which is the wastage factor.

The fact that you've got off-cuts that can be used on another job is immaterial,you've lost money on that particular job as far as the material cost is concerned.


Someone comes to you for a shelf in a european hardwood (doesn't matter which),we know it'll generally come in waney edge,or at least your local merchant buys it in that way off the agent,the shelf is,say,19mm thick by 200mm wide by what...3.3m long ?.Your customer wants it in a hurry & your local supplier has only one board in stock that'll do the job...but it's 4.5m long,600mm wide & to straighten one edge means taking off 125mm either end to 10mm in the middle of the length...now you can cut a plank 210mm wide before planing (you've got the timber,may as well cut it slightly over size).

So now you've produced a job out of a board,the nominal size being 1" X 8" X 132",no wastage,you've used 0.61 cubic foot,but to do the job you've had to buy in a board 1" X 23 1/2" X 180",volume 2.45 cubic feet,you've three times as much timber left over after you've taken out what you needed.

If you can use the timber elsewhere,fine it's bunce,if not then someone has to carry the cost of the timber.

Your customer wanted the job done,you phone up the merchant for prices & availability,give the customer the job price-it's their choice after that,you've given them a price & you're covered.

That's a very extreme example,but it can happen.

Apologies for jumping between metric & imperial,tend to use metric for measuring & setting out,imperial for buying.


...and American White Oak is not suitable for external joinery,great for internal but just not durable enough for outside.


Just previewed this...what an anorak :roll:

 

[Slim]

There's also something wrong with your maths!

100% wastage mean that everything goes to waste. If you need to buy twice as much wood as you will get usable boards out of it - that's 50% wastage.

Wrong

I wouldn't go for 100% wastage on European timbers,I'd go 300% .

300%??

Throw away three times as much timber as you purchased?

Wrong as well,but you're on the right track.

No, they are not wrong.

 

[woodbloke]

steve tighe wrote:

if you can't explain yourself properly.

Suggest you have another think about this 'cos you've completly lost me after about the firs para :? - Rob

 

[Sgian Dubh]

beech, I'm not sure I agree with your waste factors. It's my experience that if we buy what's known as FAS or FAS1F in the American grading system of kiln dried square edged American white oak you need to allow a waste factor of approximately 50%. That means to get 10 ft³ of PAR machined parts you need to buy about 15 ft³.

For the last twenty five years or so I've typically purchased what some merchants call 'prime' waney edged air dried English oak with a 100% allowance. That is to achieve 10 ft³ of PAR machined parts you'll actually buy 20ft³. This isn't always enough allowance, and with some lower grades in particular it's not unusual to 'over-buy' by 200%. Slainte.

 

[steve tighe]

Cheers Sgian Dubh 8)

 

[Bodrighy]

Blimey! I'm going to show this thread to some of the carpentry students who have been whinging about having to do keyskills maths....perhaps they ought to take up knitting instead :lol:

And in the meantime I'll stay an amateur :roll:

Pete

 

[Sgian Dubh]

...and American White Oak is not suitable for external joinery,great for internal but just not durable enough for outside.

Steve, you're repeating a factual error that I pointed out to you earlier.

I repeat, American white oaks are durable for exterior use. I offer this quotation as the first piece of evidence. "The heartwood is durable and extremely resistant to preservative treatment, and the sapwood is moderately resistant." (Lincoln, 1986, World woods in Colour, p 189.)

If you don't believe that recognised authority on the subject, you might prefer this one, "White oak Q. alba, produces finest timber of any American kind, used for furniture, joinery, building, shipbuilding, ladder rungs, wheel spokes and barrels...." (Edlin, 1978, The Tree Key, p 108). In this instance you wouldn't use white oak for shipbuilding, ladder rungs and wheel spokes if it wasn't what we in the trade know as 'durable'. Durable means in the timber technology parlance I'm familar with that the wood copes with exterior conditions either well, or extremely well.

Lastly, here's Hoadley (2000) on the subject in Understanding Wood, p 44, "Resistant or very resistant [to decay], Oak, bur; Oak, chestnut; Oak, gambrel; Oak, Oregon white; Oak, post; Oak, white."

I apologise for taking an opposite position to yours, but if you're going to repeat factual errors twice in one thread about timber technology I'm afraid I'm more than willing to point you towards correct information for as long as it takes. Slainte.

Edit. I realised this morning that in the interests of strict accuracy I should have said in this post, but forgot to do so, that European oaks (Q's. robur and petraea) are indeed generally 'significantly durable' to 'very durable' used in exterior locations. The American white oaks, eg, Q. alba don't perform as well, but most them are considered 'durable' to 'significantly durable'.

In other words, the European oaks do perform better than the American white oaks, but the American white oaks are still good performers for outside use.

Sorry to miss out the, if you like, subtle differences between the two general types of oak, but I remembered to include it eventually, so I hope I managed to clarify the situation a little better.

 

[BradNaylor]

Pricing up a job you're allowed wastage on the timber,standard practice,you don't know what boards are coming in as you've either asked for a cubic foot amount or sent over a cutting list that you need to get the components out of.

American hardwoods,standard practice is to allow 30% wastage,but you've got to take into account the finished size of what you want.

Example:- 32 X 95mm finish dado (Ex 1 1/2 X 4" ) in AWO,most merchants offer this timber in 6" or wider boards,that's at least 50% straightaway,if your lucky you'll get reasonably straight boards at 9 1/2" to 10" wide,that's a wastage of up to 25%,you've made money on the timber,on the other hand if you get a selection of boards between 6 to 7" wide then that's potentially a wastage of up to 75%,you've lost money on left over the timber.It's the amount of timber you've got left after you've got the piece you wanted out which is the wastage factor.

The fact that you've got off-cuts that can be used on another job is immaterial,you've lost money on that particular job as far as the material cost is concerned.

This talk of 30%, 50%, or even 70% wastage astounds me!

I don't chuck away any more than 10% of all the timber I buy - and probably a lot less. I NEVER order timber for delivery - I go to the yard, pick it myself, and take it away in the van. That way I get exactly what I want.

I plan my 'off-cuts'.

If I needed a 4" dado as above, I'd either buy a 5" board or a 9" board. Then I'd either have two lengths of dado, little waste or a big usable board left over for another project.

I don't know where you get the idea that 'most merchants offer this timber in 6" or wider boards'. I normally have to root through a pack to find enough wide boards, discarding dozens of 4" & 5" ones!

Oh, and since when was European Oak only sold waney edge?

Both my main suppliers (British Hardwoods and Irmass) stock it square edged. Price IIRC is from around £26.00 per cube at both, so I don't see that there is any difference in the wastage levels between European and American oak. There's not even that much difference in the price, although the strong Euro will no doubt change that.

To reiterate, if you are worried by the levels of waste you are going to get - go and select your own timber.

Ultimately though, timber cost is normally no more than 10-15% of the selling price of a project, so it's easy to become over obsessive.

Cheers
Dan

 

[Chris Knight]

First lesson learn't,don't post on here after you've just come in from the pub if you can't explain yourself properly.

You should take your own advice!

If I buy 10 cu ft but can only use 5 cu ft of it, then 50% is unused/wasted.

If plans require 5 cu ft for a job but I buy 10 cu ft because I know some will be unused/wasted - I am buying 100% extra.

 

[frugal]

First lesson learn't,don't post on here after you've just come in from the pub if you can't explain yourself properly.

You should take your own advice!

If I buy 10 cu ft but can only use 5 cu ft of it, then 50% is unused/wasted.

If plans require 5 cu ft for a job but I buy 10 cu ft because I know some will be unused/wasted - I am buying 100% extra.

It all depends on which end you look at the problem.

If you say: I need 5 cu ft of parts for this project and I have had to buy 10 cu ft (you know have 5 cu ft of parts and 5 cu ft of scrap/sawdust) then you have needed to buy 100% more wood than you needed. In this case your client has paid for 100% more wood than he needs, so that wastage is 100%

On the other hand, if you say: I bought 10 cu ft of wood, of which I only used 5 cu ft (the other 5 cu ft is now scrap or sawdust) then you have used 50% of the wood you bought and wasted 50%.

It all depends on whether you are comparing the ratio of wood needed to wood bought, or the ratio of wood bought to wood needed. It brings back memories of A level Stats where we spent more time arguing with the teacher about the meaning of the question than we did learning anything.


For me as a hobbyist I want to know how much of the wood I have bought have I used, but a professional who needs to quote clients will need to know how much wood to buy to do a particular job.