FRENCH OAK

[DAVEF]

Any body know suppliers of dry french oak. Large section timber (150x150)  for construction of mezzanine floor. Uk, Northern France, Belgium area.  

 

[zeb]

Have a look in www.pagesjaunes.fr and look up scieries de bois

You are probably surrounded by woodyards seasoning timber without knowing it! You can even buy off cuts there to use on your woodburner.

Good luck.

[Bobc]

Get in touch with Chris Head.

www.chrishead.net - look under timber supplies.

Kind regards,

Bob Clarke
http://perso.wanadoo.fr/grindoux

[Chris Head]

I'm not able to take on any more until Autumn due to existing orders and contracts but good luck with your search Dave. I'm interested to know why it is you want to have dry oak for an interior timber framing project? 150mmx150mm if felled at the right time of year, sawn appropriately and left to settle for a while before use will most certainly move a  bit, but over time it will develop shakes and splits and a character all of it's own. 

Chris

[Poolguy]

Chris is right of course.

I would go further to say that you simply cannot dry an oak beam of that dimension, and keep it whole.

The only way is to mill it down to say three 50mm boards, then dry them and glue them back together.

This notion that somehow you must have dry timber in a building is completely fallacious. All of the beams in my 16th seicle house will be as dripping wet as the day they were cut if one where to mill them through.

Fresh is good.

I would help you Dave but your too far away in N.France to make it economic.. I am sure that there is a local scerie who can give you what you need.

Andrew

[Bobc]

"I'm not able to take on any more until Autumn due to existing orders and contracts but good luck with your search Dave. I'm interested to know why it is you want to have dry oak for an interior timber framing project? 150mmx150mm if felled at the right time of year, sawn appropriately and left to settle for a while before use will most certainly move a  bit, but over time it will develop shakes and splits and a character all of it's own. 

Chris"

My mistake Chris!

I did not read the original posting carefully enough.

For the basic mezzanine framing then constructional oak would be fine and can be purchased from any decent timber yard or builders merchants - even Point P at a price!

Kind regards,

Bob Clarke
http://perso.wanadoo.fr/grindoux

 

 

[Bobc]

"This notion that somehow you must have dry timber in a building is completely fallacious. All of the beams in my 16th seicle house will be as dripping wet as the day they were cut if one where to mill them through."

Building with green timber is perfectly acceptable.

I would seriously doubt that the timbers in your house would be as wet as the day they were cut.

Having owned and restored a 16c listed building in the UK, I have cut out and cut up enough sections of old oak to know that there was precious little water content left in the wood.

Having worked on very old French properties, I have not encountered any where there was any great degree of moisture in the wood.

Kind regards,

Bob Clarke
http://perso.wanadoo.fr/grindoux

 

[Chris Head]

I had a wee experiment today, I cut in half an old 200mm x 200mm oak timber, minimum 150 years drying (from my farmer neigbour) and a 150mmx150mm beam (oak, winter felled) air dried for 15 months. The moisture content in the middle of the old timber was 20,8% and in the middle of the new timber 36,7%. Both timbers were measured in the very centre. By Andrews logic, the new timber would have a similar moisture content to the old timber, I have to agree with Bob.

Without being too much of an anorak, wood does dry over time, undoubtedly the thicker the timber the more slowly it dries, but dry it does.

Chris

 

 

[Dave&Olive]

hi all

         timber will  air dry out to a max of about 20-21% ,but you will have to allow about 1 year for each 1 inch of thickness. kiln drying will take it down further to say 12%.

            funny part that i could never work out if kiln dried timber gets wet it will air dry back to 12% , air dried will only go back to 20-21% , so something must go on in the kiln drying process ....any experts out there to tell us why.????

                        dave

hi Chris glad to see you are busy

you too Bob

 

[Chris Head]

Dave it's quite simple really, I use a process called dehumidification.

The dehumidifier is placed inside the kiln along with sensors to record the humidity of the kiln, the temperature and the moisture content of the wood, the control unit is mounted outside the kiln and is programmed to take the timber down to the desired moisture content. Basically the air inside the kiln is heated which causes the water in the timber to evaporate, the moist air is then circulated by fans, condensed and extracted.

The process is more complicated than that and there are many other parameters to consider but that's a simplistic overview. There are other methods of drying but dehumidification is the least risky.

Hope that explains it a little!

Salut, Chris

[La Guerriere]

plus of course, it's a lot easier to work and make joints in new (green) timber. All old timber frame houses were built using green timber, and they then adjusted to shape as they (very) slowly dried out. Just above my computer is an oak beam about 400mm x 400mm and knocking on 500 years old, and it's as solid as a rock. If I have to fix anything to any of the old oak in my house, I seem to need a masonry drill....

Jim

[Bobc]

"If I have to fix anything to any of the old oak in my house, I seem to need a masonry drill...."

A bit off the subject, but if you need to do a lot of timber fixing with screws, then invest in a cordless impact driver.

You can drive 100mm/6 pozidrive screws into oak without a pilot hole and without chewing up the screw head.

I have a Makita to standardise on batteries, but most of the big companies, DeWalt, Hitachi, Panasonic, etc make them.

Regards,

Bob Clarke
http://perso.wanadoo.fr/grindoux

[Poolguy]

Gee wiz

I guess I'll just have to agree to differ from my two learned friends.

The beams I have cut up number in the Hundreds and Hundreds of all different species. My moisture meter is my evidence and Bruce Hoadley amongst my sources.

My MM gives me a consistent 40-65% MC on beams bigger than 250mm sq., which leads me to the assertion that 'they are as wet as the day they were felled.' (64% is considered 'green'). Variation depends upopn where they were used in a building and what the RH was for most of their days.

Dave's rule of thumb is correct drying 1" per year' but it doesn't continue endlessly. Bound moisture (as opposed to free moisture) cannot be extracted more than a few " without lots of energy. (its physics I think). Air drying uses three sources of energy - warmth (not heat) airflow, and gravity. The last two are unless for moisture in the centre and the first will do very little. Oak paticulary is just too dense and combined with surface tension that water doesn't move.

I suspect if you have beams which are dry then they will have suffered some extraordinary forces either excessive checking, prolonged exposure to heat (not burning) or degrade. Other than that I don't know without seeing the wood and testing it.

Having said all of this I don't particularly want to fight about it because, I am personally happy with these notions and will continue to use them. If others disagree for what ever reason ( I can't imagine) that is their business. I don't want the position of 'wood nerd' either. I just wanted to dispel that nonsensical idea that ALL timber in a house has to be 'kiln dried' - I get asked all the time and the explanation (of the obvious) is wearisome.

It applies absolutely to flooring (must be kiln dried) but not at all to beams (pointless). QED

Andrew

[Poolguy]

Dave (me ol taff)

I'll just add on a little to answer your Q (over looked it... sorry)

The reason for the effect you describe is because a Kiln dried board has lost the 'bound moisture' AND the 'free moisture', whereas the air dried board has lost only the 'free moisture' (hence 18-24% max depends on RH)

Hoadley writes;

"The water held within the cell walls is called bound water. In contrast to free water which is help in the cell cavities like water in a tumbler, the bound water is help by physical forces of attraction within the cell walls".

In my own terms, think of a straw: free water inside the straw; bound water in the material which the straw is made off.

Further, when a 'dry' board absorbs moisture from high Rel. Humidity (RH), its absorbed as free water which can just as easily be lost again when the RH drops.

Guess that's all then

Andrew

[Dave&Olive]

thanks Hendo and all,

     first agree with there must be a limit to the " 1" per year rule "

 remember a photo of that my sister had  when her father-in law was in new zealand sheep farming of a tree with the road running through the centre of it  with a team of 6 oxen pulling a covered wagon . the tree must have been 40 foot across min awesome site bet the inch per year went out the window with that one.

 

       ta anyway for the info

              Dave

[epinay]

Someone 'modernised' our old stone house about 50 years ago by taking out all the original joists and beams (maybe they were riddled with woodworm or something) and built a block wall right through the middle of the house - including through the fireplace and chimney breast but that's another story (which has caused us no end of problems as we are opening up the fireplace).  Anyway, we are removing the block wall and installing green oak beams in the ceilings to provide the support that the wall was built to do in the previous renovation. 

So from the above posts about OAK, I take it we are doing the right thing installing GREEN oak beams?  Please confirm, and also please advise me what we should do to the beams - I don't want them to look treated in any way and would be happy to just leave them to dry and age in their own way.  Will this be OK?

Also, advice on how to fireproof the end of the beam that will be in the chimney?  We are installing a stove, so not an open fire obviously.

Look forward to your replies.

Thanks, Diana

 

 

[Poolguy]

Hi Diana

I'm sorry to say that my little brain is dazzled thinking of the design you have described.

You are removing the wall, OK (I hope that its not load bearing)

You are replacing it with fresh cut oak beams, great choice.

You want to leave it age without any treatment, fine, is there any sign of wood bugs anywhere else in the house??

But you want to 'fireproof' the end of the beams because it goes through the fireplace ????

I can't see what you want to do.

Oak burns .. rather well in fact if you get it hot enough. (like all timber). Can spell out more detail of your needs.

Andrew

[epinay]

I Know, I know !!!!.....when we've all stopped laughing I'll try to explain.

I can hardly believe it myself, but it's true - imagine one room downstairs with a fireplace in the middle of the longer wall.  Then in circa ??? someone wants 2 rooms.  They build a block wall smack down the centre of the room, including into the chimney (right up to and including the first floor!) and then block up the fireplace.   They had 2 small rooms and no sign of a fireplace.  Now, we have revealed the fireplace, but to see the whole thing in one eyeful you have to stand in the doorway of their block wall and quickly glance left and right and pretend the wall is not smack in the middle of your view.  Anyone watched that Dustin Hoffman film where he has to screw up his eyes to make snake eyes?  That's what's required here.  Got it??  Probably not -  it's hard to imagine, and I've seen it!   In short, half the fireplace is in one room, and half is in the other.  

SO.. we are removing the wall up to and including the first floor, and installing one oak beam in the ceiling of the first floor (where the wall is being removed) and one oak beam in the ceiling downstairs (where the wall is being removed.  So we will have one room downstairs, with oak beam going into the outside wall / chimney and we will build partition wall upstairs to divide into two bedrooms (more or less as before, but the load on the oak beam will be less than if we had left the wall upstairs), supported by the new beam downstairs.  Hence why we are removing the wall on the first floor too. 

I wish I could draw you a picture - if someone tells me how to upload a photo you might get some idea of the situation

We were advised that beam going into the wall of the chimney would be OK if fire retardent material was used and the flue was so many cms (can't remember exactly) from the beam.  Because the chimney is so wide there is room to manoevre to flue to the far side of the chimney, away from the beam.  But yes, it worries me too - hence the question re fire retardent material. 

Diana

 

 

[Poolguy]

Diana Diana Diana Di Di Di ...

I may be a bit thick, but it seems to me that you are making a mighty big rod for you back.

At least from your last post I understand what you are trying to do. If there are some other smarter people out there perhaps they can devise a solution for you. But me.... I think that you have only two options.

1. Examine the walls VERY closely and try to find any evidence of the ancient system of support for the first and second floor. If that can be discovered then it probably works well and so duplicate or rather replace it. (failing that...)

2. Why not divide the support structure into three putting a beam at one third and at two thirds ie. either side of the chimney fireplace.  Doing this you avoid the necessity to get involved with messing with the chimney, it sounds like its had a tough enough time as it is.

I really would not go with any sort of plan which involved putting a major support structure next to a fire source. I would be amazed if any engineer would pass it, insurance company would cover it, or Pompier not condemn it. In short I urge you to think again.

Andrew

By the way I was not laughing.... I was in a state of animated confusion.

 

[epinay]

Dear, dear Andrew

I like the way you have really thought about this - so many people we tell it to haven't had the stamina, imagination or staying power...

We thought long and hard about the two beam solution as you have suggested.  That was our Plan A.  We are on Plan B - the one beam solution so that the joists (put in during the earlier conversion) which are currently resting on the block wall could stay and rest on the new oak beams.  Seemed logical to us (also to the builder).  The reason we didn't go right back to the original (you are absolutely right, it would have been the best idea) is that it would have turned the house into a shell, which was more than we were prepared to undertake.  As it is, when they took out the huge original beams (in prior renovation circa 1950 or so) which went from front to back, they replaced them with smaller joists which go from front to centre block wall and back to centre block wall, stopping and resting on centre block wall - which we are replacing with said GREEN OAK BEAM (Blimey, I hope it's worth it!) to support the joists.

Re concerns about the beam being near/in the fireplace - I know it sounds mad but don't we often see old fireplaces with beams going into the chimney  - I know I have.  The fireplace is 4ft 6ins wide and we were thinking that a flue, 16" away from the beam,  surrounded by fire-proof insulation, and the beam enclosed within fireline plasterboard would be OK.  After all, look at all the oak mantels you see in open fireplaces.  I know, I protest too much!

We had two builders out to quote for the work and neither of them raised an objection.  But we are nervous and appreciate your very sensible opinions.  If we definitely shouldn't do this we have to act fast as the builder is going to start any minute, if he hasn't already!  And we are in UK at present so its a bit daunting.

Thank you so much for your interest.  I'll let you know how we get on.... providing the house doesn't burn down. 

Regards, Diana

 

[Poolguy]

Well Diana

You are, as they say 'playing with fire'.

If you proceed with this plan, and I have no doubt that a procession of builders would have no objection as its not really their job to certify that plan only the 'doing' of it, then you had better be well prepared.

Forget about fireproofing impregnation that's a gnat biting an elephants bum. (skuz tha xrprissun)

To fire rate the beam you need to wrap it as you say in fireproof blanket and then case the whole thing in concrete, as thick and as strong as you can make it. 4-5 hour fire rating is basic starting point, more if you can make it. Your architect will be able to give you a spec for that.

I presume,  that you will penetrate the wall of the chimney and back wall to rest the beam on a sound pad of concrete, binding nearly 1 meter of stone work into one (hidden in the chimney of course).

As I understand it though, all of this grief is being endured so that you don't have to replace the joists in the middle section of the room and use two beams instead of one. May I just raise the point in my naivité, that the price of Oak is at an all time low, and the price of a few decent sticks of Oak to replace the floor support is a bargain compared to the price of the works you are contemplating. Especially when the work is unsupervised (Gulp)

If I have had no useful contribution to make to your situation then I hence retire despondent. Otherwise, I can only add

take care young Di.

and good luck

Andrew

 

[epinay]

Good Morning Andrew

I hope you slept well, because I didn't. 

And we realised that we might never sleep soundly again, but hey, Fortune Favours the Brave.  Hang on though,  don't fools rush in where angels fear ..........?  

Sometimes it's hard to tell the difference . 

Sometimes it has to be pointed out to you. 

SO, you may be relieved/ joyous / overcome  to know that we have already contacted the builder and instructed him to carry out the beam either side of the chimney scenario - so that's 4 lovely green oak beams in all.  All the more character being re-injected into our little cottage .

Thank you,  Andrew ,  if not for one day saving our lives, or major fire damage to our house, then certainly for showing the way to peace of mind, sound sleep, problem-free insurance and no major flue issues to address. 

So, to my lovely new green oak beams, which is where I came in..... As there's not a lot of original oak in the house apart from the attic (which we will treat), I don't think the new wood will be savaged overnight by anything too lethal (and we aren't in a termite area), it seems that we can safely do NOTHING to the green oak beams and simply enjoy them as they are.

Merci et bien cordialement

Diana

 

 

[Poolguy]

Bon

Job done

sleep well young Di

A.

[Caterham7]

I have been following the fire debate with interest and do think you have chosen the best course of action and this is probably what most 'professionals' would recommend.

I do however feel that 16" distance to the flue together with a couple of layers of fireboard would have been sufficient to protect the oak beam.

Wood ignites spontaneously at around 450-500 deg C,I would be suprised if this temperature would be achieved.At least I hope this is the case since my green oak lintel is 150mm away from my log burner,after completely ignoring the supplier who suggested an absolute minimum of 600mm air gap!

For those that are interested oak chars at an approximate rate of 15mm every 30minutes in a fire,and it is on this basis that timbers can be designed for the appropriate fire resistance without any protection.It is interesting to note that large timber members actually perform better in fires than unprotected steel due to their high thermal resistance.

Regards Tony MIStructE

[Bobc]

"I have been following the fire debate with interest and do think you have chosen the best course of action and this is probably what most 'professionals' would recommend.

I do however feel that 16" distance to the flue together with a couple of layers of fireboard would have been sufficient to protect the oak beam."

Quite so - more than sufficent - the earlier postings seem to have missed the point that a woodburner with a flue is being installed rather than an open fire.

As so often on this Forum, useful replies mixed with misleading information.

If this is properly done with a Fumistar or Laheyra double insulated stainless-steel flue then the end of the beam could rest against the flue without any risk of combustion.

"If you proceed with this plan, and I have no doubt that a procession of builders would have no objection as its not really their job to certify that plan only the 'doing' of it, then you had better be well prepared"

Certainly in our area, no competent, registered builder would agree to carrying out any work that did not conform to French normes. There are, of course, many English unregistered ‘builders’ in all parts of France who will carry out whatever is asked of them - and may even finish it.

Regards,

Bob Clarke

http://perso.wanadoo.fr/grindoux