How to attach timber extension to Colorbond fence?

[SallyBee]

How do I attach  2.4m long X 500mm high timber fence extensions to the top of a colorbond fence? Should I cut off the shorter legs and use the longer legs to screw the extension onto the colorbond fence? Which screws (and what length) do I need and how do I use them? Thanks

 

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[MitchellMc]

Welcome to the Bunnings Workshop community @SallyBee. It's terrific to have you join us, and many thanks for your question about installing fence extensions.

Cutting the shorter leg off would be an option, but I have concerns about the rigidity of the extension due to the lack of mounting points on the fence.

As these extensions are predominantly designed for timber fences, you'd be rather restricted on mounting points when using them on a Colourbond fence. You'd only really be able to screw the legs of the extension into the vertical steel posts of the fence if they aligned with them. Potentially some additional screws could be fixed through the bottom edge of the screen into the horizontal top capping rail of the fence.

For the fixings, something along the lines of Zenith 12G x 35mm Galvanised Hex Head Metal Screws would be suitable. Just remember that you can only screw into the upright posts or top horizontal rail as the fence panel itself is a millimetre thick, and your screws will penetrate the neighbouring property.

I'd recommend you place your screen up against the Colourbond fence to see if, by chance, the legs of the extension match the posts of the fence. If you can take a picture, that would be great. If the legs don't align with the posts and there isn't anything to screw into, let us know, and I trust our members like @Nailbag, @Jewelleryrescue, and @Dave-1 will have some great advice on alternative solutions.

Please let me know if you have any questions.

Mitchell
 

[SallyBee]

Hi Mitchell thanks for your reply. The length of the screens is the same as the colorbond panels (2.4m). I did think I'd have to screw the legs of the extensions into the frame of the colorbond fence. Should I also screw the extensions screens together or leave them separate? There is no bottom edge of the extension screens to use to attach to the top capping of the colorbond fence. The legs on the extensions screens are 25mm thick, so would I need longer screws than 35mm? It's raining here today but if there is break I will try to get some more photos.

[Dave-1]

Good Morning @SallyBee 

Welcome to the Community Nice question to start out with and one most of us have run into when looking at our own fences. The pages in here have lots of privacy screen ideas.

Looking at your photo and going over what you and @MitchellMc  have been saying I would still tend to head towards the screws that he has suggested. The posts for colourbond fences are not particulary thick so 25mm of the 35mm screws being taking up with the timber screen and then 1mm ish for the metal post thickness. The rest of the screw wouldnt be doing too much.

Trying to support the screen midway was causing me to wonder, how about a mounted strip of timber from the top of the top rail to the bottom of the rail for the fence and then you could screw the center support to that timber? Think Fence pailing size/type. If you wanted to you could also have one of those vertical fence slats over the join between colourbond panels to give it a uniform look? If you go the route of the added timber for support then the screws should be changed to timber screws for screwing the screen to the vertical strips and the screws that MitchellMC has suggested to attach the timber to the fence is all.

Dave

[MitchellMc]

As @Dave-1 has mentioned @SallyBee, the wall of your post is only a few millimetres thick, so the 35mm screws will be fine. 

That's great that the legs land at the same point as the posts. When I say the screen's bottom edge, I mean the last woven piece of material. See the uprights that it weaves through? You could screw through the bottom of that upright into the top capping of the fence. 

Mitchell

[SallyBee]

Thanks for clarifying that. I will give it a go. 🙂

[Jewelleryrescue]

Hi @SallyBee 

I Read  your Frame is  2400mm matching the posts of color bond  fence,   Thats  great because  Color bond have purpose made exention post channels that screw into the existing  fence. just for fence  extentions like yours. With a  little modification.

You  will need metal screws 10g x 35mm for the colour bond. and a hex screw bit driver.

The  idea is to  use  standard  color bond metal screws (you can  get coloured ones to match your fence colour as  well as colored  rails and fence extentions to match or highlight your project. These are  bought by special  order at bunnings desk.)

1/  add fence extentions to your current fence posts they  are 340mm long so your 500mm  panel will go higher which is ok. This  will give you slots to drop your panel into and you can screw into the channel walls into your timber up rights to hold it firm, 

2 Do buy extra fence rails to  insert into the new side channels  as this will allow your panel to sit inside it supported it goes in so the channel is upside down allowing your panel to slot into it.

Basically look at your color bond fence see the posts at the bottom?  See how the bottom rail goes  between the posts and encapulates the fence metal  sheets. Well that is  your exact  same method above for your  panels of wood.  we are simply recreating this at the top of your fence where your wooden panel is used instead of metal sheeting.

This  will match your exiating fence  including the color with the strenght of  color bond steel as that extension will be facing strong winds.

If you follow  this path you will have to saw off the bottom timber legs on your panels to fit into the channels provided by the color bond metal.

Your panel will slot into a color bond  picture frame.

Here is a   guide  by project pete which  shows the steps  remember instead of stteel latice your adding your  timber  panel  instead with out the color bond top  capping.

https://www.workshop.bunnings.com.au/t5/How-To/How-to-add-an-extension-to-a-Colorbond-fence/ba-p/508...

COLORBOND Steel 340mm Domain Fencing Post Extension I/N: 0910756  $17.01

https://www.bunnings.com.au/colorbond-steel-340mm-domain-fencing-post-extension_p0910756

COLORBOND Steel 2350mm Monument Fencing Rail I/N: 0910744 $16.08

https://www.bunnings.com.au/colorbond-steel-2350mm-monument-fencing-rail_p0910744

Bremick 10g x 16mm Pale Eucalypt B8 Steel Fencing Screws - 100 Pack 

I/N: 0119468   $21.46

https://www.bunnings.com.au/bremick-10g-x-16mm-pale-eucalypt-b8-steel-fencing-screws-100-pack_p01194...

[SallyBee]

Thanks Dave some great suggestions that I will explore 🙂

[SallyBee]

Thanks for the information,  I will check out your suggestion 😊

[Nailbag]

Morning all, apologies for the late entry, it's been a very busy week. The tips supplied already by @MitchellMc and @Jewelleryrescue are excellent. The only small thing I can add is that I would pre-drill pilot holes for  the screws just on the front uprights. That will make it easier to then drill directly into the colour bond and into the rear uprights. Without the pilot hole, the upright might want to pull away as the screws are drilling in to the colour bond.