Grading Wood

[Rick Dipper]

Knowledgable People

My build progresses, we are now in the process of ordering the timber, and as normal the location issue makes life hard.

I have a neighbour with a portable log saw, who can cut trees down to any size joists and planks, and we have a good supply of trees from the local managed forrests. He can also deliver by tractor, wich helps somewhat.

The engineer has specifed D30 Grade for the Oak, and C16 for the other timbers. Unfortunatly wood from my neighbour is ungraded, and Mr Building Inspector could well get upset at this.

All the C16 timer in the wood yards is ugly, mine will be on show, so I would like some nice looking wood, Douglas Fir is favorite right now.

I have looked for an idiots guide to grading, and one does not exist, it appears that wood is "visually graded" by a "skilled" person.

The current plan is to find a suitable "skilled person" and pay him/her to trundle on out to my house and grade my wood.

Where would I go to find such a person, I have been to 3 saw mills in my area, none of them can grade wood, do I just keep expanding my search ?

Am I missing something obvious ?

Thanks Rick

[Capitol]

Not very difficult, Used to be part of good civil engineering courses.

Try

Regards Capitol

[John Rumm]

Sounds like you just need a C16 stamp and some ink! If finding somone who can visually grade the timber is that hard, chances are the BCO will not have a clue either! ;-)

[Rick Dipper]

Top Quality Idea - job sorted.

Rick

[G&M]

Graded wood must now be kiln dried in an approved kiln. Without that your friend's wood is unusable in construction - no ifs, maybes or workarounds.

[Rick Dipper]

I assume that making your own approved kiln is expenive, not beacuse of the construction (most I have seem are old containers) but for the approval certificate.

So its another example of new regulations forcing me to support the exploition of eastun europe, who sell their achient forrests real cheep with a grading stamp on, insted of supporting the local rural economey.

It a wonder my main house is still standing, with no foundations, no waterproofers, no pea shingle, and no grading of the wood when the chopped the tress to clear the site.

And of cource all the middle men in the CEE wood make it 3 times the price of the local stuff.

This is quite upsetting for me, all of the basic house materials are local, wall stone (picked off the land), slate (40 miles to the quarry) cement (works is 15 miles away), bricks, labour. The wood will come from the other side of europe.

Rick

[Grunff]

Surely there must be someone reasonably local with a certified kiln? I didn't know about this kiln certification business until I read this thread, but I do know there are two yards within a 40mile drive of me who bake their own C16 stamped timber.

[Rick Dipper]

That will be my next line of investigation. My neighbour charges 1/3 of even the cheepest graded timber I can find on line, so I can afford quite a bit of expence in drying/grading. His random oa flooring is arround 5.50 a square meter, its unfinished, but you can buy a really good sander with the money you save.

If you are neer chester/shrewsbury, maybe you can let me know who the yards are.

Thanks Rick

[Grunff]

Wow! There's a price you don't come across very often!

I'm in Devon.

Good luck - there's bound to be somewhere within ~60 miles of you.

[Steve Firth]

Christ on a bike, another pile of stupid legislation.

Yup, completely timber framed, none of it kiln dried and it's lasted over 300 years so far. That green oak garage that I had built recently must be a construction disaster as well.

[IMM]

workarounds.

About time you bulldozed it then.

[John Rumm]

Could you not get the engineer to redo calcs without using C16? They seem to quite often specify timber grades even when they aren't actually necessary.

[Anna Kettle]

Yes this is the way to go I think. I had some oak soleplate replaced this summer with new air dried local oak and the building inspector wasn't at all interested in numbers like C16

Mind you my supplier charges more than 5.50 a square meter for oak flooring. Drool

Anna

~~ Anna Kettle, Suffolk, England |""""| ~ Lime plaster repairs / ^^ \ // Freehand modelling in lime: overmantels, pargeting etc |____|

01359 230642

[sylva]

I have not been involved in grading sawn timber, though in the past we plainly did grade softwood visually before selecting which class of sawlog we cross cut it to, in the round.

I thought there was a machine graded class, M75 springs to mind for carcassing, but this is an old memory.

This is true of oak, particularly because its differential ratio of radial to tangential shrinkage locks the structure. Even then the carpenter, who was also a qualified building surveyor, I worked with did visually grade the timber, he went to some lengths to select oak poles for their final use, things like sole plates and tie beams often being quite knotty, because they would either be in tension or low compression loads without bending moments.

I think there is a higher margin of safety in oak beams than is softwood for trusses simply because the dimensions used means the grain distortion around knots is less likely to be crossed when sawn, being used is smaller dimensions on softwood this effect will be more significant.

AJH

[xavier]

Hutton & Ross (Handr.co.uk - I think) can site grade your timber for you.

As for missing something. Does the fact that green timber changes its characteristics somewhat as it's drying out not affect your project? I know green oak is often used, but green softwood????

Xav

[stuart noble]

I think a single kilning at source works fine, even below "air dry". The problems arise with secondary kilning when timber is dried once for shipping, and then again by McTimber to quickly comply with some regulation or another.

[Pete C]

Hi,

Try ringing around and seeing how much will be charged for kiln drying, or whether it's possible to redesign for non graded wood.

If you can get it kiln dried locally there is no problem. If you were the architect would you accept liability for using non graded wood when the design required graded?

cheers, Pete.

[Tony Bryer]

C16 is ordinary structural softwood. A piece of timber that wouldn't get graded as such would be rejected by any carpenter that knows his job.

[Andy Dingley]

No. Or at least, only if the architect has called for some particular grading. There's no general rule thgat says ungraded timber can't be used for building work.

Grading is by and large a sign of _inferior_ timber. What it's for is to allow unskilled chippies to slap things together "by the numbers" without they themselves having to understand timber. If you follow the gradings, nothing too bad ought to fall down.

For low-end work, grading is entirely appropriate. And I hope never to live in another house built from pre-fab roof trusses and nail plates!

At the high-end though, grading is irrelevant and inappropriate. It's the _carpenter's_ job to understand the timber they're working with, and to build competently with it. Unfortunately there's a shortage of such good people, and at £7.50/hour for timber framers then there's hardly any incentive for anyone to go into this field.

[sylva]

Joe, the green oak carpenter I worked with, reckoned to spend a day on a major joint, like tie beam to jowl post.

AJH