Used Bonding coat?

[mikegm]

Whilst on a job today, I followed a sparky colleague who recently left me a couple of 'back to brickwork'/wide chases. I used Bonding on these, which also cracked on drying, I guess because of the amount of bonding used. Did I do right using bonding?

 

[NickB_99]

Whilst on a job today, I followed a sparky colleague who recently left me a couple of 'back to brickwork'/wide chases. I used Bonding on these, which also cracked on drying, I guess because of the amount of bonding used. Did I do right using bonding?

Sounds like suction - I'm guessing you didn't apply diluted PVA to the chase first and let dry to tacky?
Bonding should be ok, just it prefers low suction background. The PVA would have reduced the suction significantly and stopped the cracking.

 

[trowelmonkey1]

spot on Newbie!

i often use Hardwall for chases personally as this only needs the bricks/blocks wetting, bonding needs PVA.

 

[roughcaster]

Good advice chaps.

 

[NickB_99]

Good advice chaps.

Thanks for the tip on the hardwall also TM1 - will bear that in mind for next time.

 

[mikegm]

Thanks guys, yes I did PVA first, unless the PVA was too weak a mix! But the chases were very deep as well as quite wide. As TM says I could've used hardwall. I'll try that next time....still learning

 

[roughcaster]

Thanks guys, yes I did PVA first, unless the PVA was too weak a mix! But the chases were very deep as well as quite wide. As TM says I could've used hardwall. I'll try that next time....still learning

I don't know how you coated it out Mike, but sometimes,, if as you said, it's very deep/wide,, don't bring it out in one coat. Wet/pva the chase, then half fill it,, scratch it, then leave it to steady up for a good while,,, then fill/bring it out flush, cleaning the wall off around the edges of the chase, with a wet brush/sponge,,, always makes the job look good.

 

[mikegm]

Sorry for the late post!! Thanks for that RC, I did only gradually fill the chase, maybe I was rushing it and filling it too quickly though....On a slightly different note, one of the walls was quite large, so I experimented by dividing the wall with a stop bead, must say it worked pretty well, but I did need to work on the 'join' a fair bit to smooth it out flush, but I guess once it is emulsioned then it will look ok.