# Forum Home Renovation Plastering  Which is the Best 'Filla?

## Batpig

'Evening Gents, 
I've got a few fair sized cracks to fill in some rendered brick walls, and I was wondering whether any of you have a definite "Swear-By" opinion of one particular type of 'Filla over the other - ie. Polyfilla or Spakfilla (or maybe something else that's new out there...) 
Is there a particular brand that is streets ahead of the others in it's "handling" properties (eg. stays moist for longer, and will stick to the wall in preference to your scraper)?
Is there one particular type that even has a weeny bit of flexibility about it, such that it tends to resist cracking along the crack-line again in the future (within reason, of course...)? 
What do you think?  :Confused:  
Thanks very much,
Batpig.

----------


## Rod Dyson

Bat pig if you have a lot of cracks to repair cornice adhesive is the way to go. finished off with top coat.  
All those fillers you mentioned do the job. But would work out very expensive for more than just a crack or too. 
If structual stress is aparent no filler will give you a permanent fix.  Cracks can appear for many reasons.  Unless there is a glaringly obvious problem my view is to fix a few of them and give it six months to see if they reappear. If not go ahead and fix them all and repaint.   
The problem is most people just want to get them fixed and painted straight away understandably so. 
I have seen a tab used that is stuck over the crack which measures the increased movement over time to access the structual element in the cracks.  Most noteably in the Historical Society building. It was determined that the old original building and an extension were drifting apart.requiring a massive underpinning job and extensive crack repair after it was established that the under pinning was successful.   
Good luck with it.  
See this web page. The same applies to rendered brick as with lath and plaster. http://www.how2plaster.com/restlath.html

----------


## rhancock

Agree with above on structural issues. 
I fill a lot of holes with builders bog, but that's mainly because it dries quickly which means you can fill, have a cuppa, sand and paint all in half an hour.  However its not as cheap as your average polyfilla, and you tend to waste more if it sets more quickly than you put it in.

----------


## Claw Hama

I agree with rod, cornace cement is great stuff and good value for money, rod may have views on this but I usually mix in a little bondcrete as well as the water. Just for good measure. never had any open up again.

----------


## Claw Hama

The quickset cornice cement goes if in 30min or less depending on the weather etc. Don't get time to make a cupa.

----------


## rhancock

That's good to know.  It's certainly cheaper than builders bog, particularly forlots of cracks. BB is very convenient for small areas.

----------


## Batpig

Great Stuff Fellas... 
Rod, unless they don't make them anymore, I think those little dooby-tabs are called "Tell-Tales". Don't worry about the movement side of things guys - a Structural Engineer has looked at the place. I just know from past personal experience that it is very hard to not get any reflected cracking at all at some stage in the future when using the normal Polyfilla/Spakfilla-type product - even on quite stable cracks. Something with the hardness and sand_ibility_ of normal Spakfilla, but with a little bit of the flexibility and stretchibility of caulked Acrylic Gap Filler would be great. Thought they would have come up with something by now, especially with the prices that are being asked. Think I know why: found out last night that Spakfilla and Polyfilla are both owned by Selleys - ie. no price competition, and no competitive need to improve the product... 
I'd have to be careful with even the normal Cornice Cement - it goes off pretty quickly for me (I could be overworking it).   

> I agree with rod, cornace cement is great stuff and good value for money, rod may have views on this but I usually mix in a little bondcrete as well as the water. Just for good measure. never had any open up again.

  Claw - do you think the Bondcrete is doing anything other than improving adhesion to the wall? Interesting comment about not having any cracks reopen - do you think maybe the bondcrete is making it hold together within itself a little better, so that it actually ends up with a little stretchability? Does the filler still end up easy to sand when dry? How much Bondcrete are you putting in? Normal PVA woodglue would have to be an adequate substitute, wouldn't it? 
Thanks again,
Batpig.

----------


## Rod Dyson

I dont use bondcret with plaster anymore since some plaster products and paint DO NOT work well with bondcrete.  I found this out the hard way. Huge patches in the ceiling just fell off!!!  Had the samples tested and the reason for failure was the boncrete.  Now we scabble the surface if we need to create a bond on a painted surface. 
To get the best bond in cracks. the cracks need to be dug out back to the substate and wet down before filling.  Citric acid or lemon juice will give you more working time with cornice adhesive.  1/2 a teaspoon to start with in a 1/2 bucket mix will give you an extra 20-30 minutes. 
Cheers Rod

----------


## totoblue

> I just know from past personal experience that it is very hard to not get any reflected cracking at all at some stage in the future when using the normal Polyfilla/Spakfilla-type product - even on quite stable cracks. Something with the hardness and sand_ibility_ of normal Spakfilla, but with a little bit of the flexibility and stretchibility of caulked Acrylic Gap Filler would be great. Thought they would have come up with something by now, especially with the prices that are being asked.

  I use Nordsjo Super Filler.  It is for interior and exterior, is a little bit flexible and is sandable.  I have used it on cracks in plasterboard that have opened up after fixing with plaster-type fillers and the crack has not shown up again. 
Super Filler is water based so I spray a bit of water in the tub and cover the surface with a freezer bag and it doesn't go off in the tub between uses.  When you want a nice smooth surface, you can work it a bit on a large putty knife and add a spray of water if the weather is warm.  You can tool a smooth surface with a drop of water and a clean blade, but it is not vital to do so as you can sand it when it dries. 
Super Filler shrinks though so for deep holes you will need a couple of goes at filling it.  Super Filler is about $35 for 2.5 litres in Bunnings (in the paint section) - you can buy smaller amounts to try it.  I am on my third or fourth tub (it is also good for window putty). 
I also use Gyprock multipurpose joint compound (premixed) which works well. 
At Bunnings, the best plaster products are generally in the plaster section - they are the professional products, not the more expensive amateur products in the paint section. 
I have tried all the Polyfilla range including the Polyfilla large cracks product.  It is a bit flexible too but not as good as Super Filler.  It doesn't sand anywhere near as well. 
One thing I have found is that different brands of products don't always work well together.  For example I have had problems with top coat plaster products sticking to cornice cement and deep crack fillers. 
I would not use a plaster top coat over Nordsjo super filler (one is flexible but the other isn't) but you can sand Super Filler to a fairly fine surface, then undercoat and sand again. 
I have tried cornice cement for plastering but it sets way too fast for me.

----------


## Batpig

Dear Rod - thanks again for your tireless advice. I'm taking it all on board. 
Dear Toto - great reply. Could be just the thing I'm looking for... 
Best Wishes,
Batpig.

----------


## blute

Second Nordsjo Super Filler, good stuff!!

----------


## Joister

hi Batpig, 
with your greeting of 'evening gents' i'm assuming you're including us female renovators as well (lol) 
good luck with your gaps

----------


## Batpig

Sorry, haven't been in for a while... 
Thanks Blute for the confirmation! It always helps to have a couple of opinions that corroborate. 
Dear Joister - sorry for the "exclusive" intro, but it's hard to come up with a snappy dry opener with more than two words in it. Like, what I mean is "Dear Ladies and Gents", isn't quite as snappy nor as dry as "Dear Gents..." But on the plus side, I don't open the car door and such for blokes, hey! (You'z don't get it too bad I reckon... :Wink: ) Heck, dress up like Shania Twain in that video clip, and then you wont feel too left out  :Rolleyes: . Have been grinding away at the gaps by the way. Am going nuts as a result... 
Thanks to both of you.
Batpig.

----------

