Battening - getting them flat and true - how?

[Dreadnaught]

I'd love some guidance from the great people here. Its about battens for external brick-slips cladding and how to get them flat and true. 

 

I've got most of the battens up and and all is going well (see photo). But inevitably I've found a couple of bulges in the racking board which I could try and flatten out. The battens are screwed not nailed so I can easily remove them,

 

Is the best approach to pack the battens with plastic packers for the low spots.

And use a cheap electric planer on the battens for the high spots. I can buy a planer from Screwfix for £35.

 

Am I along the right lines?

 

And I'm thinking to aim for a tolerance of 2mm at most. Is that OK?

 

 

[Russdl]

We used packers on the low spots and cut out the batten on the high spots.
 

We were counter battening so any gaps in the first layer of battens didn’t pose a problem for our cladding, not sure if that would work for you though?

[ToughButterCup]

1 hour ago, Dreadnaught said:

...

And I'm thinking to aim for a tolerance of 2mm at most. Is that OK?

...

 

Ughhhhh. I hated this job so much, I came to love it.  Strange, but true.

 

Two chippies helped me on our build for a short period: one sloppy as hell, 'tother, well, finicky is an understatement. Each had a different approach to the same issue. They only worked for a day or two, the cladding took me a full month (on and off)

 

2mm should be achievable quite easily: and less than that with a bit of care.

For me the key thing is - while working on your own - it takes time. Soooooo much longer than working with someone who can share the job. And by that I don't mean a willing but disinterested / clueless / completely unskilled / person. I'm trying not to say - partner.

(She won't read this, I hope)

 

I found that battens need to be held by the head of the screw: not the whole of the (in our case) concrete screw. So the batten needed to be pre-drilled. That means that you can vary the tension by a mil or less quite easily - and fookitrightup if you don't predrill the hole. Because when you come to fit the counter-batten, the process of backing off  a screw on an  under-batten which has not had a pre-drilled hole, it  pulls a large section of the batten one way or the other. Cross-making.

 

One of our  walls, in profile,  bears more than a passing resemblance to a propeller. Excellent training for battening. I ended up making my own shims (modelled on trouser shims) . Thats when I learned (from the fastidious chippy) you can use multiple layers of DPM to get the battens lined up to within half a mil...  He was on day rate. 

 

I feel almost nostalgic about it now @Dreadnaught: if you weren't so far away, I'd come and help ya...... 

 

Edited April 26, 2022 by ToughButterCup

[Dreadnaught]

9 minutes ago, ToughButterCup said:

if you weren't so far away, I'd come and help ya......

 

What a story, @ToughButterCup! Inspiring and terrifying in equal measure 😄 

But seriously, that gives me a good idea of what to expect. Thank you.

 

What was your cladding? Timber planks? 

Did the fastidious approach show well in the final result?

[Conor]

Not quite the same, but our joiner is a big fan of using strips of dpc for shimming out timber in door frames, joists etc. Can be cut easily to whatever size and don't compress.

 

If you don't want to pre drill the battens, use partially threaded screws.

[SteamyTea]

6 hours ago, Conor said:

If you don't want to pre drill the battens, use partially threaded screws

Called bolts. 

I have often wondered how to make a wobbly wall flat with battening.

Probably worth getting a couple if long straight edges.

And string.

[Temp]

9 hours ago, Dreadnaught said:

use a cheap electric planer on the battens for the high spots.

 

I wouldn't do that. The pressure treatment is typically only a thin layer on the outside. I'm in the process of losing a fence because I used a strimmer  around the posts. It damaged the pressure treatment layer and allowed the posts to rot. Other posts not strimmed are fine.

[Dreadnaught]

14 minutes ago, Temp said:

The pressure treatment is typically only a thin layer on the outside.

 

Good point @Temp. I do have a flask of creosote to hand. Already used it on the cut pieces on my fencing. I could dab some on the battens after using the planer. And fortunately its the good-old stuff that works that they don't sell anymore.

[Rishard]

All of the above is good advice on fixings, especially if your lats are wet as they are likely to dry out and lose that initial bite they have on a screw . I typically start by finding the furthest out bulge. Once this is established I set up a string line horizontally from the furthest points. Practically impossible on your own as you need a person at each end of the string and someone eye’ing the string so it is just off touching the lat at the bulge point. You now have a straight line to pack and fix your lats to. I use plastic shims as they don’t compress. From here you can plumb up your vertical lats and pack at the fixing points. Sadly in your case it might mean starting again, or finding the bulge point and packing everything else. 2mm tolerance would be fine for most claddings but with a nice long straight edge and plenty of time you could get it perfect! Hope this makes sense. 

[Troubled]

Hi Dreadnought

I was interested that you are intending brick slips on your battens. How have you progressed?

I am struggling to find a backing board, that as the structural certificate demanded by building inspector, together with non fire propagation.

The suggestion to use structural bard worries me as it says must use approved fixing, but only ones I can see are for use in masonry.

Also is in the cavity and condensation is a concern.

How have you managed?

[saveasteading]

On 26/04/2022 at 19:42, Temp said:

The pressure treatment is typically only a thin layer on the outside.

That depends on the quality of the treatment. Having built in a pressure chamber system to a timber works, I studied this in action. 

It seems to me that if the timber is treated in a powerful autoclave tank, where a proper vacuum is created (and not rushed) , then the chemicals get right into the pores.

Meanwhile I think poorer treatments are little more than surface treatment.

But the cut ends need some more however good the process was.

[saveasteading]

44 minutes ago, Troubled said:

the structural certificate demanded by building inspector, together with non fire propagation.

Building Inspectors are very wary on this, post Grenfell. One who used to take a pragmatic or common sense view told me that this was no longer an option.

Hence very difficult to prove any build-up that isn't exactly the same as a tested system with certification.

[Dreadnaught]

3 hours ago, Troubled said:

I am struggling to find a backing board

 

Oh, good point. My BCO queried my choice of racking board on the outside but was fine with the brick slips system I am using. I am using Eurobrick's P-Clad system, which uses for a cement particle board for the backing board. 

 

For racking board, I had to swap my original choice of Medite Vent board for MagPly to make the BCO happy.

 

 

[Dreadnaught]

3 hours ago, Troubled said:

approved fixing

 

I am using the fixings supplied by Eurobrick as part of their system.

[Gone West]

14 hours ago, Troubled said:

I am struggling to find a backing board, that as the structural certificate demanded by building inspector, together with non fire propagation.

I used Siniat BluClad Board 10mm with the Wetherby 15mm brick slip system.

 

https://www.insulationshop.co/10mm_bluclad_60min_fire_resistant.html

 

https://www.wbs-ltd.co.uk/systems-solutions/system-finishes/15mm-brick-slips/