Roofing best practice, does anyone follow it?

[epsilonGreedy]

When fixing my first few roofing battens I dutifully followed industry guidance and fixed the battens with 65mm x 3.5 nails driven in with a hand hammer. This did not feel right and I was concerned about splitting the battens at the ends. I quick stopped fixing battens within 300mm of a batten end to give me time to reconsider.

 

When visiting a large national chain of roofing supplies I asked what nails do the pros buy to fix battens. The unequivocal answer was "they all buy those 65mm x 2.65mm bags". Then a voice piped up in the queue behind me and pro customer chipped in advising never nail roofing battens with 3.5mm thick nails because they will split. He also advised blunting the nails by tapping them against a stone because the nails will then tear their way into the batten rather than the nail point levering open the wood grain thus triggering a split.

 

How come published sources all claim roofing battens should be fitted with stonking great wood splitting nails and a national chain of roofing merchants does not even stock such a nail for that purpose!

 

 

Edited November 4, 2021 by epsilonGreedy

[Temp]

https://roofstores.co.uk/different-types-roofing-nail

 

[makie]

Nearly every site I work on supplies nails and it's always paslode. https://www.screwfix.com/p/paslode-galvanised-plus-im360-collated-nails-2-8-x-63mm-3300-pack/502fv  tends to be the ones supplied and as you can see they don't match BS exactly. The BS isn't required by law so most people don't follow it exactly.

In regards to the merchants, when we get galvanised nails from them it tends to be these - https://www.burtonroofing.co.uk/galvanised-nails-65mm-x-2-65g-x-25kg.html

[dnb]

The Paslode nails I used had a certificate to say they complied with the BS because they had at least equal pullout resistance.

[Tom]

I've always blunted nails with a tap from the hammer before using tbh, can't remember where I picked up the habit but good to hear I'm not the only one!

[markc]

6 minutes ago, Tom said:

I've always blunted nails with a tap from the hammer before using tbh, can't remember where I picked up the habit but good to hear I'm not the only one!

Blunted nails cut the wood fibres as they go so less chance of splitting but a much reduced pull out force, no problem in shear.

sharp nails push the fibres aside and create more friction, but also increase splitting forces.

[bassanclan]

Yes i always blunt the next nail by tapping it on the previously hammered in nail when battening

[epsilonGreedy]

On 05/11/2021 at 16:29, markc said:

Blunted nails cut the wood fibres as they go so less chance of splitting but a much reduced pull out force, no problem in shear.

sharp nails push the fibres aside and create more friction, but also increase splitting forces.

 

 

That is interesting, I can now visualise the point you are making. I had not considered the counter argument to blunting nails.

 

With my rafters doubled up at 300mm centres I am less concerned about the pull out risk.

 

I guess only a seasoned roof repairer can comment on the most common mode of roof failure, i.e. is it battens lifting off the rafters or battens splitting?

[epsilonGreedy]

On 04/11/2021 at 23:25, makie said:

In regards to the merchants, when we get galvanised nails from them it tends to be these - https://www.burtonroofing.co.uk/galvanised-nails-65mm-x-2-65g-x-25kg.html

 

 

My local roofing merchant sells the same size for fixing roofing battens. The Timco band in their case.

 

This is what the NHBC says, it is strange how industry practice on this point completely deviates from the written advice.

• a minimum of 3.35mm x 65mm long (10 gauge) and a minimum of 30mm longer than the batten thickness

 

https://nhbc-standards.co.uk/7-roofs/7-2-pitched-roofs/7-2-17-battens/

 

[markc]

Rafters rarely split, I have seen loads of split battens though … usually caused by bashing the hell out of them to sink nail heads.

the 2.65mm nails are much easier than 3.35 (old 1/8) size

plus you get loads extra in a 25kg box

[David H]

Just the info I was after. I was struggling to find the industry guidance never mind preferred sizes used by pros. I will get some ordered