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View Full Version : Repair or patch cracks in internal walls















familyguy
2nd May 2008, 12:01 AM
Can this type of wall cracking be "repaired" or is patching the only thing that can be done? If it can be repaired how is it best done ? I've got a copy of the CSIRO brochure which describes the repair procedure recommended by them, but most customers freak out at the cost of the CSIRO procedure. I usually do the following:
Chip out all the loose stuff and the plaster that is no longer adhering to the bricks, once I start the loose stuff can usually be pulled off with the fingers. Often a 3mm crack ends up 120mm-150mm wide

Hammer gavlanised metal strips about 1.5mm-2.00 mm thick into the brick gaps to stop the gap from closing up in future. The theory is that if the crack closes up the patching gets pushed out of the crack causing the wall to bulge at that point. I do this about every 120mm-150mm all the way down the crack.

Apply bonding agent to the bricks, then trowel motar into the crack almost level with the existing good plaster. Usually have to use a scraper here to apply the motar as a trowel is too wide.

Plaster over this with cornice cement/patching plaster.

Finich off with skim coat flushing compound which may need a light sand when dry to make truly flush.

All this is very time consuming is there a better faster and or better way?

I was replacing some cracked tiles in a shower alcove and I watched the painters for a while, a quick scrape with a scraper, fill the crack with super fine plaster, a quick sand when its set then on with the paint.

Am I being too fussy? Seems to me there must be a quicker better way. Some times I find fibeglass tape from a previous repair (the type used for gyprock) under a crack, as its torn in two I have to pull it away which makes even more mess.

Is this type patching better?

There's been a few very dry years in SA which has caused a lot of cracking even in previously stable houses, most people don't want to know about soil engineers and reports they just the cosmetics taken care of


Some advice would be appreciated

rod@plasterbrok
4th May 2008, 12:30 AM
This has worked for me for years.
http://www.how2plaster.com/restlath.html

Cheers Rod

familyguy
4th May 2008, 11:34 AM
Thanks for the reply, I did read those but wasn't sure if it applied to brick walls also.

Claw Hama
4th May 2008, 12:20 PM
Slipping the metal in before bogging up sounds like a good idea (metal or some timber wedges)

keepontruckin
8th May 2008, 08:14 PM
Buy premixed mortar mix and follow the instructions on the pack. Add around 100ml to 200ml of bondcrete to the mixture. This will allow an extra strong bond. The bricks will need wetting before applying the mortar mix to stop the bricks from absorbing moisture from the mortar mix and will stop it from cracking. Use bondcrete again for the wetting agent and follow the instuctions on the container.
One you apply the wetting agent, apply the mortar mix with a trowel starting from the top and finish at the bottom. Using a piece of timber level the mortar to the existing wall. Allow to dry for 24 hours then apply plaster top coat. Works a treat. good luck

DavidG
9th May 2008, 12:28 AM
:iagree: Plenty of bondcrete.