How to hide joint cracks on a rendered Blueboard cladding?

My 22 year old townhouse in Melbourne has rendered blueboard cladding on the upper storey. Every joint between two sheets has cracked render. It has been like that for many years, there is no moisture entering the house, it is just an eyesore.

I have finally decided to do something if I find someone to do it. It won'tbe easy due to the design of the house and poor access from one side.

I can't consider new cladding or re-rendering. There is no room for those options - there is no roof overhang or eaves.

I don't want timber battens - it would alter the look of the house too much.

I am considering to cover the cracks with a 50 mm wide strip of 6 mm thick fibre cement sheet - like the HardieFlex.

Thin FC strip painted with the same colour as the rest of the cladding may not look too bad, I think.

What I am not sure about is how to affix the strips to the cladding, so I do not end up with cracks of the strips.

Should I use screws, construction adhesive, etc etc.

Has anybody done repairs like this? Has anybody seen a better idea of covering the cracks?

I would very much appreciate help with the fixing question, and/or suggestions that I have not considered yet.

The pictures may not show all cracks, but believe front front back backme, they are there.

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Comments

MitchellMc

Welcome to the Bunnings Workshop community @Josef. It's great to have you join us, and many thanks for your question about conceal cracks.

I guess there are a few options here. The first would be a repair, which entails chasing out the cracks and widening them slightly so they can be patched with a cement filler or a polyurethane sealant like Sikaflex 11FC. You could certainly use strips of Hardieflex attached with construction adhesive and clouts. The clouts would be less likely to crack the strips than screws. Another option would be to use Brutus 50 x 6mm x 2.4m Building Moulding Cover Trim, as it's around the same size and thickness as your Hardieflex strips; it has a smooth surface on it though.

Please let me know if you have any questions.

Mitchell

Josef

https://www.workshop.bunnings.com.au/discussion/comment/35661#Comment_35661

Hi Mitchell,

Thanks for the reply to my post.

I have seen patched up cracks in render, and they do show even after two coats of paint. The filler or sealer does not have the texture of the render - that is the problem. And they would crack again anyway - according to a renderer with 40 years of experience. Blueboard is a very bad cladding product he says, specially for large areas.

I will go for joint cover strips. I have seen the Brutus strips in your store, and they look good (expensive). But I read that PVC has relatively high coefficient of thermal expansion, and on that 2.4 m length, it could be 2 mm. They say that paint on them could crack, and I wonder what would the adhesive do.

So I think that strips cut from HardieFlex sheet would be safer. They do not expand nowhere as much.

Problem - they don't seem to be available off the shelf, and are very expensive to have them custom cut.

If you know of a place where I could get them cut at a reasonable price, I would appreciate if you let me know.

Would Bunnings do it?

Josef

EricL

https://www.workshop.bunnings.com.au/discussion/comment/80107#Comment_80107

Hello @Josef

I'm sorry but the store does not have a cutting service for HardieFlex sheets. However, I suggest posting the job on Airtasker or Hipages. I recommend putting in as much detail as you can regarding what you want done with the HardieFlex sheet. In this manner the trades person reading the add will be able to give you a quote quickly.

If you need further assistance, please let us know.

Eric

Jason

https://www.workshop.bunnings.com.au/discussion/comment/80107#Comment_80107

Hi @Josef,

Hope all is well.

Just checking in to see how you are proceeding with this repair?

I know its a very common problem so I'm sure community members will be keen to see the results.

Feel free to also post if you need any further assistance. We're here to help.

Thanks,

Jason

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