Blown "NEW" render

[Makeitstop]

Hi all,

Opinions on this one.?

My daughter has been having part of her old victorian house re-rendered.
Looking at it yesterday I notice it has the odd patch which has blown, as it can clearly be heard when its given a tap with the knuckles. Now this is new work done only within the last few weeks, and to me, is not what you'd expect.

The brickwork is old, and the mortar bonding it was pretty soft and crumbly, possibly lime based. The wall was treated with SBR before the scratch was done.

Any views on this appreciated.

 

[Hodgo]

That doesn't sound good atall. Im trying to find out about lime render and if a stainless mesh should be applied before application as I have a customer requiring a lime render and I totally want to avoid anything like what your experiencing. Hopefully someone will come back with something. sorry i cant help any more than that. regards Hodgo.

 

[1john]

Were there any bricks loose? What backing plaster or render was used, was in sand and cement with multi finish over or what?

 

[Micilin]

'Treated with SBR' - do you know how exactly?

Was it just rolled/brushed on ?
If so how many applications and timing?

Or mixed with Cement? Timing?

 

[Makeitstop]

From what I recall, it was mixed with cement and maybe a little sand, brushed on, and the scratch coat was applied pretty much within half and hour of that being done. Don't know whether this is correct or bad practise.

The overall job looks ok, but to me, new render should not feel or sound as though it has either had issues with the top coat failing to bond well with the scratch, or not bonded to the brickwork underneath it at all. There's a definite variation to the sound when tapped, with certain areas appearing fine and solid, while others are hollow, making a rattling sound when you give it a knock. Shouldn't it sound solid wherever it's tapped over.???

To my mind, it's a big problem waiting to happen, but I guess I could be wrong.

 

[Makeitstop]

'Treated with SBR' - do you know how exactly?

Was it just rolled/brushed on ?
If so how many applications and timing?

Or mixed with Cement? Timing?

To answer your points raised above....

SBR was brushed on - only once - left for no more than 20 minutes before scratch coat was started to be applied. Yes, it was mixed with cement.

I have looked at this work again after about a week or so and the blown areas are definitely more widespread than I'd initially noticed. At first, it appeared it was only on the first section which had a top coat, but on further checking it, that appears to be on the second part given a top coat also. Strange thing is, the builder that has been doing this work brought a different plasterer to do the second part to the first, and it seems the mix is completely different on that second part, as the colour of one is WAY different to the other.

He has been told of the problem and has said he'll send someone around to take a look at it, but I am not holding my breath.

What would casue this new render to blow so soon after application.???

 

[Micilin]

'Treated with SBR' - do you know how exactly?

Was it just rolled/brushed on ?
If so how many applications and timing?

Or mixed with Cement? Timing?

To answer your points raised above....

SBR was brushed on - only once - left for no more than 20 minutes before scratch coat was started to be applied. Yes, it was mixed with cement.

I have looked at this work again after about a week or so and the blown areas are definitely more widespread than I'd initially noticed. At first, it appeared it was only on the first section which had a top coat, but on further checking it, that appears to be on the second part given a top coat also. Strange thing is, the builder that has been doing this work brought a different plasterer to do the second part to the first, and it seems the mix is completely different on that second part, as the colour of one is WAY different to the other.

He has been told of the problem and has said he'll send someone around to take a look at it, but I am not holding my breath.

What would cause this new render to blow so soon after application.???

Okay, not jumping to conclusions yet . Sbr mixed with cement is good, but without sand in it would need the render to be applied to it while wet or tacky IF on a surface with little physical key. Not sure if after 20 mins this would be the case (ie may have dried out) . BUT if there was enough of a phsyical key, then the dried SBR/OPC would not be a problem, and may have helped with suction.

The colours of the coats should be different if you are talking about succesvie layers (I'm not sure) , the one closest to the brick should be darker ie stronger.

Surface colour of different areas can be dependent on the time they were rubbed up, thickness as well as strength. You'll see this if there is a 'miss' in the floated coat which will be a different colour than the bit that the float rubbed -even though they are the same mix .

Have you taken any off?
Are the coats bonded to each other?

 

[Makeitstop]

Not taken any off no, because we are waiting on the guy sending someone around to look at it.

To me, it doesn't appear that the two coats are properly bonded together, though i might be wrong and it could be the scratch which has not taken to the brickwork below in some areas.

I am a little surpried at how weak it appears also, because in places if a finger is rubbed back and forth over the surface it can pretty easily scrub the top coat off. It seems very crumbly and nowhere near strong enough to me.

The major concern though is that it just feel so hollow and blown in places when it's tapped with the knuckles, and does not give the same solid sound as when you knock against solid brick / blockwork.

 

[grandwizard]

sounds like the top coat has blown could of dried out too quick

 

[Makeitstop]

Hi all,

Well, it's been a while since I last posted anything about this job.

The images below are of a part of this stuff that has been applied to the walls as I've mentioned earleir in this thread, and shows just how shocking it is. This is a patch I have removed, in order to see how loose it was and get a few pics here for comment. As you may be able to see, it's coming off with ease and is like this in very large areas with some pretty horrific cracking going on. It's a massive disappointment to my daughter who has already spent well over £1K in having this done. She has refused to pay anything else to this guy and has asked him to come out to discuss it. He initially promised to get onto it and sort the issue, but for the last month or more has avoided her, and her fiance's calls. It seems clear now that he's looking to cut his losses and step off the job altogether.

What are the views of you all looking at this one.???

To me, this is woefully short of being an adequate standard of work. The render is soft and weak, can be rubbed off with finger pressure and is very easily crushed in your hands. It's a P**s poor job in my view, but I'd love to hear the opinions of anyone else that can be bothered to read all of my whingeing here.

Thoughts anyone.?

Untitled

• Makeitstop
• 29 Aug 2011
• 1

Untitled

• Makeitstop
• 29 Aug 2011
• 1

Untitled

• Makeitstop
• 29 Aug 2011
• 1

 

[joe-90]

Grand Wizard is right - the top coat hasn't bonded to the scratch coat. Render is notorious for sucking the water out of the following coats so what happens is the top coat dries out instead of setting via chemical reaction. All you are left with is damp sand/cement that will never harden. It'll have to be re-done.

 

[Micilin]

Grand Wizard is right - the top coat hasn't bonded to the scratch coat. Render is notorious for sucking the water out of the following coats so what happens is the top coat dries out instead of setting via chemical reaction. All you are left with is damp sand/cement that will never harden. It'll have to be re-done.

As joe and the wizard say, looks like top coat will have to come off, and any loose cleaned off well. Possibly a SBR slurry before finish coat

It may also have been overmixed or put on in very warm weather, but the scenario above seems likely.

Is the scratch coat keyed to the wall?

If you throw a cup full of water onto it (scratch coat) when dry, does it suck it very quickly?

 

[Makeitstop]

Thanks for the replies guys, much appreciated.

The scratch coat looked ok to me (though I've got limited experience and knowledge with this) although it did appear to be a bit soft, and nowhere near as hard as I thought it should be. I was of the opinion myself that the top coat had dried way too quickly, but thought I'd check in here and get some pro advice and views.

Micilin.....I'll check it on the cup of water thing and will report back.

This might turn out to be just as much an expensive job for the builder who did it, and perhaps more so. He is a young guy, and quoted VAT on the initial job, but failed to provide any VAT number, and has seemed very unwilling to provide receipts for any of the work. This has also P****d off my daughter and her partner, and they've been looking into it. The bad news for him is that she has legal contacts and he is an accountant / auditor, and between them, they know exactly how to cause him all sorts of agro. This has been spelt out to the guy through voicemail (after many attempts at just getting him to speak to them about the job). We are pretty sure is isn't VAT registered, and if he isn't, he's not going to be a happy chappie when he gets a call asking him to attend an interview about his business. It's been very disappointing to see these two young people go through this, because they've borrowed the money to do the job and now a big part of it has gone. Still, between us we will sort that side of things.

The least he could have done is come out and said "look, I've done what I can and I am lost as to how to fix it" That would at least have given them clear indication of where they were with him. But no, nothing at all, just avoidance.

I really do feel for the honest tradesmen out there, because they often get tarred with the same brush as the guys who treat customers like this.

He's a muppet, and he deserves all he gets if HMRC rip him a new one.

 

[Micilin]

Being mindful of all the legal niceties, as long as he has had ample opportunity to put it right etc where do we go from here.

How much has he been paid to date?

You'll need to get someone else to have a look at it to put it right.

I'm hoping your scratch coat is okay . If you can't scrape it away easily, and it is not 'live' or hollow, then that's good. As it will be less time and material to fix.


You'll be able to hack off the rubbish top coat yourself , and clean it up for the plasterer.

Are there beads used and if so are they stainless steel?

I'm only asking about the water on the scratch coat to see if it needs hpsing down /sbr slurry /rendaid - but your new spread will advise on that


I hope the original chancer sees sense, but if not I have no sympathy for him at all. We all make mistakes, it's how we deal with them that shows us who we are.

 

[Makeitstop]

Being mindful of all the legal niceties, as long as he has had ample opportunity to put it right etc where do we go from here.

How much has he been paid to date?

You'll need to get someone else to have a look at it to put it right.

I'm hoping your scratch coat is okay . If you can't scrape it away easily, and it is not 'live' or hollow, then that's good. As it will be less time and material to fix.


You'll be able to hack off the rubbish top coat yourself , and clean it up for the plasterer.

Are there beads used and if so are they stainless steel?

I'm only asking about the water on the scratch coat to see if it needs hpsing down /sbr slurry /rendaid - but your new spread will advise on that


I hope the original chancer sees sense, but if not I have no sympathy for him at all. We all make mistakes, it's how we deal with them that shows us who we are.

Good posting here.

This guy has had more than enough chance to talk about this problem at the very minimum, but he will not take a call. Strangely enough though, when my daughter calls him from her phone (voicemail again....surprise surprise), he texts back straight away and asks who it is, as he doesn't know the number. What a cretin.

The scratch appears to be bonded ok, but to me it feels a bit on the softish side. It can be scraped off with not an awful lot of effort, which I'd have thought would not be good. Surely it should be hard and more like what you'd get a decent mortar joint.? Am I wrong on that one.?

Yes, it would be nice to be able to hack off the old top coat, as it would save on cost, but then getting up a ladder to the upper level of it doesn't sound too appealing, and in some ways, I'd rather aim them the cash to sort this than get too far into doing it myself. God knows I've done enough work there already in their house.

Yes, beading was used and yes it looks to be stainless. To be honest, looking at what we've got from this guy now, I'd not be surprised to see the beading made of cheese, he's that much of an idiot.

Finally, I couldn't agree more with your last comment, it's very true.
Professionals too make mistakes and get things wrong or in a mess here and there. But, the measure of anyone is how they handle that problem when it arises, and how good the finished product is at the end of their efforts. So far, this guy is just not measuring up.

Will report back with news on this.