Roof timbers

getfit

My block layers will be finishing up soon so I will be getting a cuttings list shortly from my roofer. I have been told that "foreign" timber is of superior quality and easier to work with.. - but also more expensive.

So far in the build I've always opted for the costlier options such as better/more insulation, steel lintels where concrete lintels would have done or higher grade concrete in the floors etc. as I can see a genuine benefit to the standard of the house.

However, I am not convinced that the extra few k on foreign timbers will have any long term benefit to the house. I have agreed a price with my roofer so I'm not going to pay for timber that is easier to work with for his benefit, he's getting well enough paid as it is...

What experiences have people had with the Irish timber v foreign timber debate?

topcatcbr

getfit wrote: »

My block layers will be finishing up soon so I will be getting a cuttings list shortly from my roofer. I have been told that "foreign" timber is of superior quality and easier to work with.. - but also more expensive.

So far in the build I've always opted for the costlier options such as better/more insulation, steel lintels where concrete lintels would have done or higher grade concrete in the floors etc. as I can see a genuine benefit to the standard of the house.

However, I am not convinced that the extra few k on foreign timbers will have any long term benefit to the house. I have agreed a price with my roofer so I'm not going to pay for timber that is easier to work with for his benefit, he's getting well enough paid as it is...

What experiences have people had with the Irish timber v foreign timber debate?

He is right in what he said
Why would you use steel lintles when concrete would of done I see no advantage in this.
I do see the advantage in using better quality timber

1 Fewer knots (easier to work) leading to better cuts
2 More uniform grain = less likly to twist & warp
3 Usually better dried (lower more consistant moisture content) = less shrinkage after

Also some advantages to irish timber

1 Locally sourced = a) lower embodied energy, b) promoting irish produce keeping wealth irish c) less expensive

irish climate is not the best for softwood production Most goes into manufactured boards and paper product as result.

Mellor

The difference between irish and imported timber is that the imported stuff is stronger.
This is not to be confused with better quaility.
Better quaility timber would, imo refer to grain and the finish.

Structural timbers are given a strength class, based on testing or visual inspection.
If you had two simlar timbers, one irish, one imported. The imported one is a class higher than the irish. So can achieve further spans, or be shallower. And will cost more. But bare in mind its th strenght class that costs more, not the fact that its imported You can choose an even stronger irish timber which would cost more again.

I don't think they are easier to work with, maybe harder.


All in, try not to get hung up on native or import. Choose a suitable timber and strength class to do the job.
Use IS 444

Mellor

topcatcbr wrote: »

1 Fewer knots (easier to work) leading to better cuts
2 More uniform grain = less likly to twist & warp
3 Usually better dried (lower more consistant moisture content) = less shrinkage after

I think you are mixing up two issues.

Less knots, straighter grain et all do result in stronger timbers.
But, thats the difference between GS and SS grade. Imported timber is stronger due to the growing process. It does however have narrower grain.
So if you have two boards, with the same knots and grain, they would both get the same grade GS or SS, but the import is a higher strength class.

Mellor

Oh, and I agree on the plus for going native, EE, home grown etc
and also on the concrete verses steel lintols

ircoha

getfit wrote: »

..... I have agreed a price with my roofer so I'm not going to pay for timber that is easier to work with for his benefit, he's getting well enough paid as it is...

An interesting mindset: have u considered asking him what effect the better/stronger/easier to work with timber will have on his price?

Mellor

ircoha wrote: »

An interesting mindset: have u considered asking him what effect the better/stronger/easier to work with timber will have on his price?

v.good point, and also, if it was easier to work with, he'd likely br able to do a better job

topcatcbr

Mellor wrote: »

I think you are mixing up two issues.

Less knots, straighter grain et all do result in stronger timbers.
But, thats the difference between GS and SS grade. Imported timber is stronger due to the growing process. It does however have narrower grain.
So if you have two boards, with the same knots and grain, they would both get the same grade GS or SS, but the import is a higher strength class.

I was not mixing up anything I was meerly describing the visual dipperence for the lay person not classifying their structural/strength classification.


GS ie General Structural, NS normal structural or SS special Structural mean nothing to the lay person.


PS
something which may also help
if you you use a stronger grade of timber eg C24 SS EW (stamped on end of timber) rather than C14 GS B/S you should be able to reduce the size of the timbers reducing some of the cost. (will always be more than using irish timber)

Slig

There are issues here that I think are going beyond the OPs question (my opinion)

the important factor is the strenght class. It must be stamped on the timbers (standard irish ones are C14 & C16) If the timber has a higher strenght class stamped on it then it will be stronger and could possibly result in a reduction in size or quantity of the timbers depending on the spans, centres and sizes. Forget aabout the Irish/Import factor Look at price and strenght
If you are building a dormer then reducing the size of the timbers may reduce the depth of your insulation, increasing the centres would increase your insulation.
It is a matter for your supervising Engineer/Architect to be involved in especially if they have calculated out the timber sizes and they are certifying that it is built to specification.

sydthebeat

use IS 444 to size your timbers....

it doesnt matter where they come from as long as they are stamped to do they job theyre designed for.

topcatcbr

my last word

Twisted or warped timber can be very hard to work in relation to hips valleys or dormers. Is it worth the extra cost involved? This will depend on the complexity of the roof.

Im not saying that Imported timber will always be straighter than irish but it will be far more likely. The supplier and how the timber is stored can have as much to do with this as where the timber comes from.

If it is easier for him to do a better job then that has to be better for you also. He may know a supplier of quality timber its his job why not trust his opinion.

the quality of the timber is the important issue not where it comes from. Imported timber is generally of better quality than irish timber

muffler

topcatcbr wrote: »

my last word

Twisted or warped timber can be very hard to work in relation to hips valleys or dormers. Is it worth the extra cost involved? This will depend on the complexity of the roof.

Im not saying that Imported timber will always be straighter than irish but it will be far more likely. The supplier and how the timber is stored can have as much to do with this as where the timber comes from.

If it is easier for him to do a better job then that has to be better for you also. He may know a supplier of quality timber its his job why not trust his opinion.

the quality of the timber is the important issue not where it comes from. Imported timber is generally of better quality than irish timber

Couldnt agree more.

Villain

I gota quote for roof timbers for my garage, Brooks Imported timber 2,200 Local Native 1,660

Mellor

topcatcbr wrote: »

I was not mixing up anything I was meerly describing the visual dipperence for the lay person not classifying their structural/strength classification.


GS ie General Structural, NS normal structural or SS special Structural mean nothing to the lay person.

My point was that they have nothing (or little) to do with it being imported or not.



Anyway, the general vibe is the same, forget
where it comes from, and just concentrate on the strenght class.

getfit

Thanks a million for all of the responses - very informative and helpful....

I'm glad people educated me on the different strength classes, as there is a genuine cost benefit/quality analysis that can be done based on that.

Seeing as a few picked up on my example of going for steel lintels over concrete, I'll explain myself. My project manager explained that he has attributed some settling cracks etc. in past builds to concrete lintels with spans of over 4ft (could be more than that, can't remeber exact distance now). Therefore, any windows/double doors over the span he specified used steel lintels. He has noticed very slight bows in past builds with concrete lintels used in longer spans. It's probably being over cautious, but I trust my project managers 30+ years of experience and quality reputation over my own guess work....