Roof timber - building regulations?

SodiumCooled

Hi All, I am currently getting quotes from builders providers for the roofing of my house. I have 4 quotes back now based on the list provided by the roofer I have chosen to do the work. The final builders provider who has provided a quote has underlined the "White Deal Rough 50X36mm (2X1 1⁄2) treated lats as not complying with the 2018 building regulations for slating and tiling? Any idea what that's about, no other builders provider who quoted mentioned anything in related to this item (although they all listed them as 50x35mm which I guess is simply a computer system difference)?

muffler

Timbers can be planed or un-planed. You pay a little but extra for planed laths which are the correct type.

SodiumCooled

https://www.boards.ie/discussion/comment/119580693#Comment_119580693

Thanks, it seems a very subtle difference for something doing job as opposed to something you want to look nice. What's the reasoning behind it? The fact all builders providers automatically opted for the un-planed even the one who highlighted it as not meeting regulations tells me most people must opt for the unplaned? (planed or un-planed was not specified on the list).

Gumbo

https://www.boards.ie/discussion/comment/119581717#Comment_119581717

Then you pay the roofer to plane them on site.

SC024

https://www.boards.ie/discussion/comment/119581717#Comment_119581717

never seen planed all over timber used for slating / tiling. Pure waste of time & money + PAO timber is never treated unless requested specifically & paid for. Always either 2 x 1 treated (45 x 22mm) or 2 x 1 &1/2 Treated (45 x 35mm) can be single batten traditionally but counter battened is becoming more common. Never seen or heard of any one planing treated timber on site to use for slating / tiling. If a length is particularly bad you just don't use it. simple as

SodiumCooled

I haven't had a chance to talk to my roofer about this yet but from mentioning it to some other people the consensus is nobody uses planed laths - rough treated laths are the norm.

sydthebeat

all the battens need to be is strength graded.

i havent heard of the need for them to be planed in order to comply with SR 82:2017

heres chadwicks selling SR82 compliance unplaned (rough) 50 x 35 battens:

https://www.chadwicks.ie/all-products/4-8m-50-x-35-sr82-rough-white-deal-battens-14803.html

heres the DOP

https://www.chadwicks.ie/media/supporting_document/GLB%20-%20Declaration%20of%20performance.pdf