A few comments on my point of view on the recent thread, and it's not meant to stir things up so will delete it if needs be. This is a serious thread about a few issues so if anyone wants to go flaming etc, start your own one and leave this one abuse free!
This is an internet forum, so we can expect a bit of banter etc but I think most of those who are here - and there are good tradesmen here - know where the others are coming from. While I might be the most sarky old timer going, I don’t see the need for out and out abuse but that’s just personal – if you mixed me a bucket with lumps in it that could change!!
Right so down to the nitty gritty on some points raised
- If someone paying you to do a job asks you to do something you don't want to do ?
I would tell them why it's a bad idea, make sure they know the worst case scenario and that any remedials are their baby. If they still insist on it, I'll do it to pay the mortgage. This would also be mostly site work where it is someone else’s baby - in domestic work I think we have to be more mindful of our responsibility to a customer who might not know what they are doing (perhaps has even been reading a load of tosh on a forum!!) Here , If you can’t persuade them and worry about you reputation/consequences to them you should walk away.
I've done the other too, when younger - i.e. walked away from work when I only had myself to keep. The choice is easier then. The moral high ground is easy to reach if you don’t need to carry your overdraft on your back to get there .
The obvious caveat would be a safety point of view , which is rare in plastering (say a sand and cement ceiling onto hangers that won't take the weight)
- There are some things we do that are not in the book , but by trial and error we find out. You weigh up risks/benefits. If you go off spec and something happens, then you are liable. There is often a better way of doing things, usually within spec . However, EVERY thing we see as standard now was once a new (off spec) way of doing things – time proved it as standard (spec) or it fell by the wayside
An example would be on a job where you want bonding to go off quickly. You could add cement, but if anything happens and it is sent for analysis, it will show up and you are liable. However if you add dirty water from a cleaning bucket , or premix some bonding beforehand, keep it alive and add to the mix this will drive off the bonding and can never be detected in analysis, as you are just adding the same material to your mix.
-Some specs are outdated – such as those for skimming which specify 6 mm of finish or covering sand and cement with damp hessian for 7 days before skimming or only skimming the dark side of the board etc. Materials and methods have moved on, but architects often still copy old specs . I’ve seen this loads of times and always referred them to the manufacturer’s spec, and ask the architect to show me the source of their spec (which is usually a spec from their last job!)
- Some things you can do with experience that are not standard practice – like skimming soft hardwall or bonding, adding finish to a bonding coat (to make half and half )and laying that down with finish etc You are not interfering with the integrity of the materials but have a method that has been practiced over years. Here the success/failure is purely the quality of finish – the adhesion etc is all fine and standard.
- The on site NVQ is a nonsense, a complete and utter sham and I would stand by that statement in a court of law, having done mine last year due to a long running dispute with the CSCS to renew a card (no time for that here!!).
-The thread about the use of bonding plaster to key render - I have questions on that are just that, questions to find out whether is a good way of doing things as there are two issues – integrity of the bond/ need for the process. This asking for info was lost as the thread broke down.
First of all the need for the process – if as stated before putting on the bonding the surface must be prepared (PVA’d or must be a rough surface) this makes me wonder why the bonding is needed as you can render onto a prepared or rough surface anyway. ie prepare the surface with a slurry and render straight onto that. Or render onto a rough surface. Regardless of whether it works/sticks /is off spec , the use of a bonding coat to me is adding an extra operation that is not needed. What is the advantage of it?
I can’t see that it is a good idea to put stronger /heavier material onto weaker/lighter material (without fixings) as this one of the basic principles of building/plastering /engineering . I can see that a good key on the bonding will keep the render stuck to it, and all things being equal without hacking it off can’t see it falling off.
However you can’t say that the render on top will guarantee no damp getting into the bonding (this is my biggest issue with what used to be an external wall).
You can’t guarantee that movement or expansion/contraction due to temperature will make not make them behave differently and ruin the key. For example, imagine a ceiling with bonding on it, then render – that movement with the softer bonding moving behind a rigid render will eventually weaken the key.
A good rule of thumb is - if it’s not good enough for a ceiling, don’t put it on a wall!
Comments welcome
This is an internet forum, so we can expect a bit of banter etc but I think most of those who are here - and there are good tradesmen here - know where the others are coming from. While I might be the most sarky old timer going, I don’t see the need for out and out abuse but that’s just personal – if you mixed me a bucket with lumps in it that could change!!
Right so down to the nitty gritty on some points raised
- If someone paying you to do a job asks you to do something you don't want to do ?
I would tell them why it's a bad idea, make sure they know the worst case scenario and that any remedials are their baby. If they still insist on it, I'll do it to pay the mortgage. This would also be mostly site work where it is someone else’s baby - in domestic work I think we have to be more mindful of our responsibility to a customer who might not know what they are doing (perhaps has even been reading a load of tosh on a forum!!) Here , If you can’t persuade them and worry about you reputation/consequences to them you should walk away.
I've done the other too, when younger - i.e. walked away from work when I only had myself to keep. The choice is easier then. The moral high ground is easy to reach if you don’t need to carry your overdraft on your back to get there .
The obvious caveat would be a safety point of view , which is rare in plastering (say a sand and cement ceiling onto hangers that won't take the weight)
- There are some things we do that are not in the book , but by trial and error we find out. You weigh up risks/benefits. If you go off spec and something happens, then you are liable. There is often a better way of doing things, usually within spec . However, EVERY thing we see as standard now was once a new (off spec) way of doing things – time proved it as standard (spec) or it fell by the wayside
An example would be on a job where you want bonding to go off quickly. You could add cement, but if anything happens and it is sent for analysis, it will show up and you are liable. However if you add dirty water from a cleaning bucket , or premix some bonding beforehand, keep it alive and add to the mix this will drive off the bonding and can never be detected in analysis, as you are just adding the same material to your mix.
-Some specs are outdated – such as those for skimming which specify 6 mm of finish or covering sand and cement with damp hessian for 7 days before skimming or only skimming the dark side of the board etc. Materials and methods have moved on, but architects often still copy old specs . I’ve seen this loads of times and always referred them to the manufacturer’s spec, and ask the architect to show me the source of their spec (which is usually a spec from their last job!)
- Some things you can do with experience that are not standard practice – like skimming soft hardwall or bonding, adding finish to a bonding coat (to make half and half )and laying that down with finish etc You are not interfering with the integrity of the materials but have a method that has been practiced over years. Here the success/failure is purely the quality of finish – the adhesion etc is all fine and standard.
- The on site NVQ is a nonsense, a complete and utter sham and I would stand by that statement in a court of law, having done mine last year due to a long running dispute with the CSCS to renew a card (no time for that here!!).
-The thread about the use of bonding plaster to key render - I have questions on that are just that, questions to find out whether is a good way of doing things as there are two issues – integrity of the bond/ need for the process. This asking for info was lost as the thread broke down.
First of all the need for the process – if as stated before putting on the bonding the surface must be prepared (PVA’d or must be a rough surface) this makes me wonder why the bonding is needed as you can render onto a prepared or rough surface anyway. ie prepare the surface with a slurry and render straight onto that. Or render onto a rough surface. Regardless of whether it works/sticks /is off spec , the use of a bonding coat to me is adding an extra operation that is not needed. What is the advantage of it?
I can’t see that it is a good idea to put stronger /heavier material onto weaker/lighter material (without fixings) as this one of the basic principles of building/plastering /engineering . I can see that a good key on the bonding will keep the render stuck to it, and all things being equal without hacking it off can’t see it falling off.
However you can’t say that the render on top will guarantee no damp getting into the bonding (this is my biggest issue with what used to be an external wall).
You can’t guarantee that movement or expansion/contraction due to temperature will make not make them behave differently and ruin the key. For example, imagine a ceiling with bonding on it, then render – that movement with the softer bonding moving behind a rigid render will eventually weaken the key.
A good rule of thumb is - if it’s not good enough for a ceiling, don’t put it on a wall!
Comments welcome
