What length of nail plug for battens ?

[jack hammer]

Hi all, my first post here. Just need some guidance on what length of nail plug to use!

 

I want to fix lengths of timber battens (24mm x 48mm x 3000mm) to an aerated concrete block outer wall.

24mm is the depth of the batten.  (I´ll use 24 x 100mm at the corners)

I intend to use fischer N 8 x 80 nail plugs, at approx 50cm spacings along the length.

I´m going to fix lightweight aluminium cladding to these battens.

Am i going too short here or do i need a bigger/longer plug? (8 x 100 ?!)

Thanks in advance all,

 

[Construction Channel]

Hi Jack and welcome

 

how thick are the blocks?

aerated blocks are notorious for giving a poor fixing, if you are using nailable plugs I would go as deep as possible, personally, i would consider using concrete screws although they will be slower and dearer, i would be more confident that it got a hold .

 

HTH Ed

[Russell griffiths]

I don't think length is the critical thing here it is finding a good plug that works with your blocks, some of the lighter aircrete blocks can be a sod to get a good fixing in, I think doing some tests on some spare blocks would be the first thing I would do before buying a few hundred plugs. 

I remember really struggling to get a good fixing in aircrete, but we found a plug that screwed itself into a twisted little mess that never shifted. 

[Nickfromwales]

I just drill excessively deep and insert regular red plugs. I then put a No.12 screw into the plug so it over expands. 

A bead of expanding foam ( lowxexpansion pink grip board fix ) along the full length prior to fitting works wonders.   

I'd never for one second use hammer fixings for this. Massively unreliable in aerated block. . 

And welcome to the forum . 

[jack hammer]

Thanks so far all. The thickness of the wall, inner to outer is 30cm. I´ve done a few tests to one side and used a 7mm bit so that the 8mm plugs had a tighter fit. Seemed to work OK !! Strangely ( irritatingly!) i´ve seen identical looking nail plugs from other manufacturers where they state that they aren´t suitable for aerated concrete, and these from Fischer apparently are! There are some out there solely for aerated blocks but they´re about 3 times the price! I am tempted ( as Nickfromwales says) to go for standard plugs, and just do it the slower, but safer, way! 

 

 

[PeterW]

I won't use anything else than Fischer plugs now - they are worth the small extra price to pay as they work first time. 

[Nickfromwales]

Hitting the next fixing loosens the last imo so 'knock-in' fixings are a no go for me. ??

[jack hammer]

Spoke to a local roofer yesterday and he also says nail plugs in aerated concrete are just not to be depended on! I´m going to go with Fischer universal fixings plugs and decent screws. It´ll take a bit longer but at least i´ll know i´m safe! As Nickfrom  says, hitting the next nail plug, i can see that loosening everything back off again!!