How to fix rendered brick corner?

[Kim11]

At the bottom of the house corner, some render but also some of the concrete foundation has come off as it looks. The bottom corner of the first brick on top of foundation is exposed. This is in very wet and humid weather (Darwin area). 

- I understand that I best patch this up with mortar and then seal, but am not sure about which products to use. Bondcrete with sand and cement? And then what on top? I still have some of the outdoor paint, so just need to know whether I need a sealant under the paint.

- Also given high humidity at the moment, I am not sure how much to do now and whether to wait with some steps until dry season.

- Also, how slowly do I need to build it up with mortars - in layers? How thick? and how long do they have to dry before the next layer?

- how do I stabilise the corner at the end - any tips to get the shape? angle iron? angle beads - or are they not quite sturdy enough?

any tips would be highly appreciated

 

[EricL]

Hello @Kim11 

Welcome to the Bunnings Workshop community. It's sensational to have you join us, and thanks for sharing your question about your external corner wall.

My best advice is to wait for the weather to improve and to allow the corner to totally dry off. Repairing it now will trap moisture inside and will cause the patch to crack or fall off. Once the corner is totally dry, I propose using Bondall 1L BondCrete Cement Additive to prime the surface and improve adhesion. I suggest using Sika 20kg Sika MonoTop-352NFG Structural Repair Mortar to patch the damage. I recommend using a stiff bristle brush to stipple the surface of the render and blend it in with the current finish. 

Please cover the surface with builder's plastic should it begin to rain to prevent damaging the patch. Make sure that the patch is totally cured and free of trapped moisture inside before you begin painting.

If you need further assistance, please let us know.

Eric

[Kim11]

Hi Eric,

Thank you very much for the warm welcome and for your advice – it’s very helpful! 😊

I hope I’m not overstretching your generosity, but I have a few additional questions:

• Can I leave the wall as it is through the monsoon season until May/June when conditions are (hopefully) drier, or should/can I take any precautions now to prevent moisture rising in the render or mould developing?
• Do you recommend applying a metal angle to stabilise the corner after the last layer of mortar (before painting)? If so, do you have a suggestion for one that’s available at Bunnings?
• Lastly, thank you for pointing me toward a repair mortar available at Bunnings in Darwin. I was just wondering if there might be a better option if I order a product from Bunnings interstate shortly before using it (I suspect some products aren’t stocked locally due to weather conditions).

Thank you again for all your guidance!

Kind regards,
Kim

[EricL]

Hello @Kim11 

You are more than welcome to keep asking questions. We are here to help.
 

• I suggest covering the surface with builder's plastic and using Bear 48mm x 25m Clear All Weather Tape or similar to hold it in place. This will prevent the damaged section from getting drenched in rainwater. 
   
• Installing a corner angle bead is a great way to get a perfect corner finish and add extra support. I propose looking at the Siniat 3.5mm nib 32 x 3000mm PVC External Render Trim. 
   
• The Sika 20kg Sika MonoTop-352NFG Structural Repair Mortar is ideal for your situation. However, you can use Dingo 10kg Structural Mortar Repair Bag as an alternative. 
   

If you have any other questions we can help with, please let us know.

Eric