crackholehole-repairwallsweather-resistant
Finally, I was not able to Limit the extent of cracks in the wall roughcast, which is finally cracking:
I have removed the crumbling parts, and protected the wall with a plastic sheet waiting for a dry weather.
What is the best method to fill the hole (about 25 cm wide or 10 inches) and make a clean junction with the borders?
My first thought is square flush tubing plugs. they come in all sizes, for tubing up to like 6".
Check out this web site: Mocap square tubing plugs
Should be pretty easy to pry out with a small tool when you need to. They are not advertised as perfect seals to keep out water, but unless an area depression causes standing water right by the hole, I bet they would do a pretty good job.
This is how I ended up solving it, maybe this will help someone in a similar situation out.
After talking to the building regulations guys, I ended up fixing this hole using alternative 1 above (more or less).
A 40mm concrete slab was cut and placed in the hole, standing/jumping on it seemed very solid.
Added 80mm insulation on top of the slab and in the gaps on the sides so the concrete doesn't just run down into the hole.
Ten put down a damp proof membrane sheet before pouring 40-50mm concrete on top (no mesh needed). Building regulation guy suggested 60-70mm thick concrete on top as that would not crack as easy, but 40-50mm was fine
Best Answer
You'll need to pry, chip, scrape & wire brush off any & all loose, soft or mushy stucco, possibly tripling the hole's size. This has to be done if you don't want your patch falling out very or fairly soon after it's done.
But, any stucco, cement or mortar mix does & will work perfectly. Buy a bag of small gravel & insert the gravel into the wet cement product for a very close match to the surrounding pebble-like finish.
That's all I did 20-years ago in my first place & it's still there with no signs of any problems. Additionally, any surface cracks should be finger force caulked with a white latex caulk to avoid more future holes.