Are 18 gauge brad nails going to be suitable for external cladding?

15 Sep 2017
Reaction score
United Kingdom
I'm building a shed/ workshop and am just about to clad the frame. I'm using 25mm V-match, tongue and groove. I've bought a decent quality air nailer to work with my compressor. Tried on a sample of V-match to scrap timber and the brads do seem rather thin and I even managed to pull my sample apart with bare hands. Is this normal and does the strength lie in the number of multiple fixings? Or have I bought the wrong tool for the job? If so - what should I be using?
I want to do the 'secret nailing' technique into the tongues so I don't want to use anything that will either split the tongue or restrict the smooth passage of the tongue into the groove.

Also - are galvanised nails suitable for outdoor cladding or should they be stainless steel? It isn't an expensive cedar or anything like that. Just ordinary, tanalised pine or something like that.
Last edited:
Sponsored Links
Galvanised nails are fine for outside cladding, or stainless steel if you're near the sea, but 18 guage brads are not suitable for the job. But I think you may be doing the job the wrong way round. You nail into the groves on hardwood flooring, and into the tounge on cladding. Are you fitting it vertiacally, or horizontally.
No, I'm inland, not near the sea. It's external cladding. So, as you say, the nail goes into the tongue - which I intend to do. The cladding will be fitted horizontally.

What gauge brads would you recommend?

A friend has recommended that I use what I have and place two brads, side by side. I suppose this could give added strength laterally but the pull out is what I was thinking about. Then again - the nail is going in, down at an angle and each board will be locked into place by virtue of the tongue & groove. It's ocurred to me, the only direction they can pull, is upwards and I can't see that happening, since the next board is (hopefully) keeping it in place, by securing it vertically.
Last edited:
I wouldn't work on brads at all. Your reasoning is sound reagrds to pull, but you've also got the wight of the wood on each section above it, each piece only being held in place by the nails. If one piece were to be iffy, then the lower pieces would start taking the wight. Look on Youtube, go for nails, and upgrade your nail gun.
Sponsored Links
Thanks for your advice, mate.
So with regards to upgrading - what nail gun would you recommend for this job?
Last edited:
Something like 1-1/2in ovals - I'd drive the with a 12 to 16oz hammer, though, and use a nail set (hollow-headed nail punch) to drive them under as required. IMHO 16ga and 18ga brads are just too light and have insufficient head size to prevent stuff being blown off in winter weather (bearing in mind that I live in the wet and very windy Pennines) and the small cross section also means that if they get wet they will rust out a lot faster than conventional (hand) nails. Even ovals have better holding power than that. The only power-driven nails I've come across which might do are 15ga ones. These aren't that much thicker than 16ga one, but have considerable larger heads (and therefore greater pull-out resistance), however te comments about rusting out still apply unless you go to (very expensive) stainless ones. I've rarely seen these used in the UK, though, because hand nailing is a lot cheaper and very few people ever undertake sufficient volume of work to make buying a 15ga gun viable (they are, after all, £400+)

DIYnot Local

Staff member

If you need to find a tradesperson to get your job done, please try our local search below, or if you are doing it yourself you can find suppliers local to you.

Select the supplier or trade you require, enter your location to begin your search.

Are you a trade or supplier? You can create your listing free at DIYnot Local

Sponsored Links