Buying Lumber

[GrahamB]

Due to the helpful advice and comments that I have received so far from people on the forum I am looking at buying a thicknesser (prob Makita 2012) and getting hold of some raw lumber.

Since I work away from home all week and the local lumber yards do not open at the weekend I will need to get my wood delivered rather than go and select it myself.

My question is how much do I need to allow for wastage?

I am looking to make a coffee table out of oak approx. D.60cm x L.100cm H. 40cm with a glass insert in the top of the table, similar the those in the pictures below (sorry about the size, they are copied from the Lombok website)

Thanks for the continued advice

Graham

 

[wizer]

Have you made a drawing? a sketch? If you can work out all your timber dimensions and lengths, make a parts list. Then you can go on to work out how much wood you'll need, adding about 15-25% for wastage.

 

[StevieB]

But what are you constituting as wasteage Wizer? Splits shakes and knots that make the timber unsuitable for your purpose? Can you specify boards that do not contain these or is it a case that you get what you get and if you dont select it you get what those who can select have rejected?

I have recently priced the timber for a workbench - adding an extra 15-25% makes a huge difference for wasteage in terms of price. I guess a day off work and a trip to the yard might be more cost effective?

Steve.

 

[Sgian Dubh]

... local lumber yards do not open at the weekend

Lumber yards? You must have been reading American woodworking books or surfing American woodworking sites and I guess you're rather new to the subject. There is nothing wrong with that; everyone has to start somewhere.

However, British wood merchants will look at you askance if you describe them as a lumber merchant; they are called timber yards or timber merchants here in the UK.

Anyway, here is one answer to your question. Waste allowance varies from species to species, and the form in which the timber is sold is also a factor. Waney edged boards are always more wasteful than square edged stock, and there are always faults in timber that can’t be used. It’s also necessary to cut pieces about 100 mm longer than required to allow for planer snipe and other machining faults at the beginning and end of each board.

I usually calculate the volume of timber required for a job as follows.

Estimate the rough sawn board requirement that will yield the finished dimensions. For example, ten pieces at a finished size of 800 mm X 44 X 18 (31-1/2" X 1- 3/4" X 3/4") will come out of ten pieces of rough timber 36” X 2” X 1” = ~0.42 cubic feet. Using this method you allow an additional waste factor even though you've calculated using rough sawn board sizes. Waney edged English oak has an additional waste factor of about 100%, so price for 0.8 cubic feet. As examples of typical additional waste factors, use 50% for walnut, cherry 30%, and poplar 20%.

A second method used by many is to calculate exact finished sizes with a percentage added for waste, but it can be seen that the waste factor allowance must be higher-- in my experience about double the factors suggested in the first method. Slainte.

 

[ByronBlack]

It all depends on how good you are. I'm quite rubbish so I allow for 40% wastage, but I think 25% would make sense, most timber I take delivery of these days seems to be pretty poor and has a lot of unusable sapwood, knots, warps etc..

 

[kenf]

Why not order more than you need even allowing for wastage? That way you will build up some stock for incorporating in future projects. Wood will only get more expensive. So, within reason, stock is as good as money.

 

[ByronBlack]

Why not order more than you need even allowing for wastage? That way you will build up some stock for incorporating in future projects. Wood will only get more expensive. So, within reason, stock is as good as money.

Thats a very good idea, even if you have too much, there'll be plenty of forum members who'll gladly reduce it for you.

 

[StarGazer]

GrahamB,

You give your location as Oxford, try WG Powell in Cowley road,
certainly they are open Saturday mornings, usually have oak/ash
etc in 1inch sawn planks, thicker materials to order.
They often have thicker offcuts available as well.

StarGazer

 

[GrahamB]

Thanks for the replies.

Yes I have to confess to surfing American sites and am very new to the subject... :lol: Will try to use more English phraseology next time :lol:

Understand and have taken on board the comments about allowance for wastage from planing etc. I guess it is the sapwood/knots etc that has me confused. How much of a problem is this, is it easy to see what is sapwood? Can I specify that I do not want this when ordering or state that it will be used for furniture etc as a way of avoiding?

Is my best bet to create a cut list of the pieces and sizes that I need and provide this to the Timber Yard or do I add them all up and say I want x cubic feet of a certain thickness and width?

Apologies if this is a stupid question but have become a bit confused with all the reading that I have been doing (must be those American sites!)

I do like the idea of buying more than I need but I really am very short of space and as I will be turning the kitchen into my workshop I think I am already pushing my luck! :lol:

Cheers

Graham

 

[ByronBlack]

Sapwood can be easy or difficult to notice depending on the species, I'm not a major expert, but in darker woods, the sapwood tends to be lighter, in lighter-woods, well I've not had the problem yet so can't advise on that.

If your buying rough-sawn unseen you'll have to realistically expect knots, defects etc.. the yard aren't going to send you their best boards, the best bet if you can is to go to a yard that is commutable and ask if you can see the boards before you buy, this way you can avoid the worst boards.

However, I've always mentioned it, and i'll mention here again. But ebay for me has been a succesful way to buy timber/lumber. There are number of excellent and reputable sellers who'll show you pictures of the boards so you can assess their quality somewhat before you buy, I've got some great stuff of there and for better prices than I could get at the yard.

My local yard normally give me a price based on a cutting list - so I would always say it's best to give that to them rather just how much in a cube you want. This way they can organise their timber better. For example, in my last purchase for a project, they managed to sell me some cheaper off-cuts that were ideal for a number of smaller components, I wouldn't have got this discount if I asked for a specific cubic amount.

P.S I store my timber under my bed, you'll be surprised how much you can get under there and the Mrs' usually doesn't know about it

 

[The Shark]

Hi Graham,
I'll probably be burned at the stake for heresy here, but I would like to add to the debate on wastage.
Whilst I agree that shakes are not good, knots can be used to your advantage in as much as some would say that the odd small knot actually adds character to a piece. Something to bear in mind maybe when choosing which timber to use.

Malc

 

[wizer]

I've read dozens of methods of working out how much lumber for a project. It's not an exact science. You should always aim to buy more than you need, because what happens if you run out or c*ck up?? You could get some more, but what if the colour is slightly different as it's from a different tree? If this is an early project for you (or first) then even more reason to over order. Don't worry where you're going to store it. You will find a place. Even if it has to go outside under tarpaulin, it won't ruin it.

Some lumber yards won't be happy to play about with your sketches, you might not be so lucky as Byron. So get an idea in your head before you go or call, in case you get a miserable git. Might be an idea to ask them what thicknesses they stock sawn boards, then work back from there for your project.

Clear as mud?

 

[ByronBlack]

I would like to clarify a point Wizer has bought up about sketches/cutting lists.

Usually when I go in with mine (or usually email/fax it) I tend to find out what thickness/width boards they generally sell and quickly work out what I need in terms of the boards, this only takes a few minutes, and mitigates the 'miserable git' issue that Wizer rightly pointed out can sometimes happen at yards.

Although in the three or so different yards I've used, if your honest and up front and say that you are a beginner, they are usually more than happy to accomadate with a cutting list, in fact two of the yards I first used insisted on it in case I made a massive error in working out how much was needed

 

[OPJ]

Get in touch with John Boddy's up in Yorkshire and ask them to send you one of their catalogues - there are some excellent explanations on wastage in sawn timber and what constitutes to a defect, etc.

At college, we're told to allow 100% wastage on home-grown waney-edged timbers and somewhere between 35-45% on square-edged, imported stuff from North America. With timbers like ash and oak, you may be able to get away with less than a 100% waste allowance. But, with something like walnut (particularly the American species), sapwood is a HUGE problem (to most people, anyway...) and so, you should always prepare to buy "plenty" more than you need.

If you're in Oxford then, I read about a new company (in Good Wood) called Deep in Wood (I think?) who specialise in home-grown, "native" timbers. I'll always encourage anyone to support yards like this. Don't know what their opening hours are but, they may be worth a look. :wink:

 

[StarGazer]

Thanks for the heads up re Deep in Wood, they are based in Abingdon, a similar distance from me as Powells.

StarGazer

 

[hpl]

In my experience most of the main timber suppliers are happy to work to a cutting list, but I usually find that you get much more timber than you need if you do this. I try to work out what sort of size boards I will need to get the project out. If I am going in person to the yard I them select what I need based on this, and then get some extra as there is usually defects that I've missed while in the timber yard.
I think that this will be your easiest option as working to cubic meter sizes and allowing for wastage has many variables and it is very easy to end up with either too much, or even worse, too little and you then have to wait until you can get more timber to continue the project.

Johnny B

 

[Jake]

Get in touch with John Boddy's up in Yorkshire and ask them to send you one of their catalogues - there are some excellent explanations on wastage in sawn timber and what constitutes to a defect, etc.

It's an excellent catalogue alright - but he could save some time and half a tree by grabbing the PDF of it from their site.

 

[Sgian Dubh]

I was wary of mentioning this to you earlier Graham as I sensed you are new to the furniture game, a fact you confirmed, but there is another factor to consider. The numbers I gave you earlier as wastage factors are applicable to UK 'prime' or 'superior' grade, depending on the timber yard nomenclature, and north American FAS and F1F grades. Grading terminology is somewhat inconsistent from yard to yard in the UK, but the American system of appearance is strictly adhered to by north Americans.

If however you choose to purchase a north American hardwood it will have been graded in north America using the north American system and will have been exported as FAS (First and Second face graded), or F1F (One Face Graded), or you might come across what is sometimes exported as a 'comsel' grade. This last grade is not a grade that strictly falls into the north American grading system, but is quite often put together by timber driers in north America for the export market. Comsel is a combination of timber from the the Selects and No 1 common grade, both of which are lower than FAS and F1F grades.

In the end, as a novice, your best option is to find a timber yard that is sympathetic to your inexperience, is willing to help you out, and guides you through the minefield of buying the wood you need so you don't end up with a pile of useless boards. If you have a woodworking friend or acquaintance that is willing to help you out that would be good too. Fortunately, most retail timber merchants in the UK nowadays are sympathetic to people in your position. I hope someone in your area will point you towards such a merchant, but when I worked in Oxford I bought quite a bit of wood from Timbmet based on the dge of the city. I recall they were quite helpful to the students I pointed at them, and perhaps they are still that way. Slainte.

 

[Richard Findley]

I'm a bit late on this one but for what it's worth I've always found that buying hard wood is a pain in the ar*e!!! Boards are random sizes, both in width and length, sold in the most bizare way, ie cubic metres and are rarely consecutive ie have different grain patterns!!!

I don't want to put you off but it's worth mentioning!!

I've found that you're probably best to work out how much you need in cubic feet/metres, (multiply width by length by thickness of each part and add it all together) find out what the average board width and length is and base your calculation on that! But it's not easy and expect to get it wrong the first couple of times!!

Hope this helps

Richard

 

[hpl]

But if you can go to a small local timber yard then you can usually buy planks that are sawn from the same tree and are stacked together, especially with the home grown timbers. These may be random widths, but so are trees, fortunately, but at least you will be getting as consistent a colour, grain pattern etc. as is possible from a natural product. A trip to a good local yard should make it easy, buying timber is not that complicated, especially when you can see the product you are buying.

Johnny B