Summer house/ workshop with C16 timber instead of c24 any good?

[Jonny Vee]

Due of timber cost going mad day by day I was thinking to use c16 4x2 timber to make a garden summer house/ workshop in conjunction with 18mm plywood.

Would you use c16 as main structure for the walls and what is the real cons against the c24?

Thanks

 

[^woody^]

Will make no difference at all

 

[Jonny Vee]

Will make no difference at all

Do they still last x number of year as c24?

 

[^woody^]

No, they are all from the same trees

 

[Jonny Vee]

No, they are all from the same trees

it may change just the stamp and increase the price in the end

 

[conny]

C24 has a denser grain than C16 and can handle heavier loads across wider spans.
It is usually imported timber because it's grown in climates where it grows slower, hence the tighter fibres.

 

[Jonny Vee]

C24 has a denser grain than C16 and can handle heavier loads across wider spans.
It is usually imported timber because it's grown in climates where it grows slower, hence the tighter fibres.

It's gonna be used for external wall at 2.4m. Do you reckons any difference with c24?

 

[^woody^]

C24 has a denser grain than C16 and can handle heavier loads across wider spans.
It is usually imported timber because it's grown in climates where it grows slower, hence the tighter fibres.

No, no and no.

Timber is graded by stressing it on a test machine and then depending on how it copes with the test load it is categorised as c16 or 24 or another grade.

It's nothing to do with grain or imports.

So in this case, the grade of the timber has nothing to do with the wall panels.

 

[tony1851]

All things being equal, C24 is about 20% stronger in compression parallel to the grain than C16. But your wall panels will not be supporting a load anywhere near the maximum even a C16 section could support, so there is no structural advantage in using C24.

 

[conny]

No, no and no.

Timber is graded by stressing it on a test machine and then depending on how it copes with the test load it is categorised as c16 or 24 or another grade.

It's nothing to do with grain or imports.

So in this case, the grade of the timber has nothing to do with the wall panels.

I Suggest you tell these guys then.

Graded Timber C16 & C24… all you need to know! - W Burton and Sons

 

[^woody^]

I Suggest you tell these guys then.

Graded Timber C16 & C24… all you need to know! - W Burton and Sons

I suggest you tell your private commercial company to tell the BRE or BSI instead.

 

[conny]

In that case there must be loads of companies under the wrong impression because I checked a number of sites and they all seem to be under the same illusion.
I'm not saying timber isn't stress tested, in fact I'd be concerned if any building materials were not stress tested, but the bottom line seems to be to make grade C24 then that is timber which is usually imported due to the way it grows.
You appear to be saying that no C24 timber is from export. Can you explain why?

 

[^woody^]

In that case there must be loads of companies under the wrong impression because I checked a number of sites and they all seem to be under the same illusion.
I'm not saying timber isn't stress tested, in fact I'd be concerned if any building materials were not stress tested, but the bottom line seems to be to make grade C24 then that is timber which is usually imported due to the way it grows.
You appear to be saying that no C24 timber is from export. Can you explain why?

You stated

C24 has a denser grain than C16 and can handle heavier loads across wider spans.
It is usually imported timber

And that is not the case. A section of beech has denser grain, and can potentially not meet the grade, and yet a section of wide-grain knotty pine may.

Likewise a timber from a tree in England may meet the the grade and some from British Columbia may not. It's not usually foreign grown either that meets c24 standard.

So your statement is incorrect.

A piece of timber with any grain structure and timber from anywhere is tested and graded. That's how it works. Nothing to do with grain, nothing to do with where it grew up. You are obviously googling websites for info and regurgitating what you find, without knowledge of the process.

 

[conny]

Your quite right about my knowledge of the process but, as an engineer, can you explain to me how a wider grained wood can be stronger than a close grained wood, unless it is something to do with the thickness/length of the fibres.

 

[^woody^]

Its not just the grain of the timber that determines it's potential strength. Knots, sap veins, splits, checks, shakes etc all play a part, as can the part of the tree the section is cut from and the type of cut used to get the sections from the trunk .

Whilst some species are inherently stronger in certain ways than others, the density of fibres is not a way of grading timber. So there can be instances of a wider grained section of one piece of timber can be stronger than a closer grained for the reasons above.