Help please! Rusting beading on new house

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op,im not up on regs much but i haven't seen galve on site for many years,maybe ten or so,i think you have good cause to complain but you may find its the subbys fault and may not get recompence!!
lol big word for me that!

 

[kevsw]

I have wrote to NHBC

Has anybody got this standard BS-EN-13914-1-2005 and what does it say about galvanised steel for external rendering? Whate were the regs in 2005 when my house was built?

What are bell casts, stops and how can I tell f they are galvanised?

 

[Micilin]

I have wrote to NHBC

Has anybody got this standard BS-EN-13914-1-2005 and what does it say about galvanised steel for external rendering? Whate were the regs in 2005 when my house was built?

What are bell casts, stops and how can I tell f they are galvanised?

I don't have, I'm afraid.

A bit of reading here (albeit from a manufacturer with a not so vested interest)

http://www.renderplas.co.uk/BS-EN-13914-1-2005.php

Stop beads are for applications where a straight joint or junction is required. You may find them used at movement joints, or against metal frames. In timber framed houses you may see them under the windows to give a movement joint.

Bell cast (sometimes called 'render stop' or 'drip' ) are the bead found at the bottom of the main elevation of render, which divides the main render from the plinth. The plinth is the band at the bottom of the wall - it may be rendered or brick.

How to tell if it is galv or SS? Well it's a silly answer but not meant to be , you tell by looking at them - you can tell by the surface usually. AS mentioned above check the joins and ends where oxidation occurs as the surface is broken.

I doubt if someone using galv angles would pay for s/s stops and drips. In any case, you are not supposed to mix them due to possible electrolytic reaction.

Keep us informed, as we want the poor practice builders to be punished.
IF they skimp on beads, how else do they cut corners (no pun intended!) to save money? Hold back on the cement? Try to get it done in one coat?

It's hard to compete with a price for render which includes beads that are a fraction of the cost of the proper ones.

Edit- I would also say that regardless of the letter of the spec, anything you buy must be 'fit for purpose' . A render with rusting beads is not that.

 

[kevsw]

The NHBC is coming round next week to inspect the rusting beading.

Can people in the trade confirm whether or not rubbing down to bare metal (just the parts rusting) and then rust priming and re-rendering and painting is a permanent solution?

 

[Alastairreid]

The NHBC is coming round next week to inspect the rusting beading.

Can people in the trade confirm whether or not rubbing down to bare metal (just the parts rusting) and then rust priming and re-rendering and painting is a permanent solution?

Not in my book it is not! when those beads start corroding they are usually beyond saving.

 

[kevsw]

The NHBC is coming round next week to inspect the rusting beading.

Can people in the trade confirm whether or not rubbing down to bare metal (just the parts rusting) and then rust priming and re-rendering and painting is a permanent solution?

Not in my book it is not! when those beads start corroding they are usually beyond saving.

Thanks just pre-empting what the NHBC and Builder may suggest as a cheap option when they start wriggling!

 

[Micilin]

Agree with Alastair 100%

 

[kevsw]

Hello, hopefully people are still reading this, the NHBC inspector visited last Thursday together with a Rep from Taylor Wimpey, waiting for report. The Rep certainly knew what he thought the causes was but didnt elaborate!

I have discovered a few other things that I need advice on:-

1. I have photos from December 2005 when the house was being constructed and the render had not been applied, in fact the render must have been applied sometime in late December 2005/January 2006 because I moved in February 2006 i.e. in the middle of Winter- could this have contributed to the corrosion issue- render not drying out, is this acceptable practice?
2. I have observed other rendered houses on the development and there are two others affected in the same area and no others are showing rust!?
3. Can anyone advise me of the NHBC standards covering rendering and external beading and when it should be carried out i.e. is Winter a no no?

 

[SpunkyTheMonkey]

i don't see why it would affect the corrosion issue but winter is an unacceptable time to be rendering and could very well be the cause of the blown render on your house.

it's possibly more of an issue here (or not?) since we're using cement/lime/sand render, afaict most uk rendering is just sand/cement, but still, subjecting fresh (uncured) render to freezing temps is asking for trouble. lots of rain followed by freezing temps is begging for it.

if you're going to render within a couple of months of sub zero temps (which isn't so smart in my book), "best practice" would dictate that you cover the render in hessian/bubble wrap/nylon sheeting...obviously there is no chance whatsoever they did so on a new estate build.

 

[Alastairreid]

alastairreid your lack of knowledge disturbs me ,tyrolean?,are you a milkman?

Just seen your obnoxious post!

Not so easy to tell from a pic is it?


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[marshman]

I'm thinking they was stuck on with finish.

 

[Micilin]

Rendering in winter is not a problem . It is the prevailing conditions over those few days of rendering that are the problem. A hot day in summer is less suitable than a mild day in winter.

So merely saying they should not render in winter will get you nowhere . Builders are not going to stop selling houses over the winter.

You could ask for the site program or records of when it was rendered and look for the weather at that time. (Met office will help, but getting true site record less easy). A frozen render would not affect it rusting now in the least, but it would show they were not working to best practice.

If you could find out if downpipes were on before rendering it would help, but how you can do this I have no idea. Again it is showing poor practice rather than a cause. But ask the builder for details.

The problem is simply galv beads , and it would not matter what day of the year it was rendered, they rust over time. They have been cut, they've been scored by render, and they are not suitable for outside work.

It's basic stuff that any tradesman would know - however if his guvnor telss him to do it?

 

[SpunkyTheMonkey]

there are 2 problems, 1 is the beads, the other is the blown render which is the one i was talking about.

i don't stop selling houses in the winter either, and we normally get harsher winters where i am than a lot of the uk does. that doesn't mean i get to shrug my shoulders and ignore what time of year it is. if i render in the middle of december then some of it is going to fail. with the lime/opc/sand render we use, the weather over the entire period that the lime is calcifying matters. since sand/opc render is doing something else at a chemical level when it cures it may not matter for as long, i don't know and already said as much, but the bottom line is, if you choose to do things at less than ideal times of year and in less than ideal ways, it's really down to you to sort it out afterwards. 'i have to keep building' is a bs excuse.

 

[Nige F]

Hello, hopefully people are still reading this, the NHBC inspector visited last Thursday ?

Winter/Summer / the name of the sub contract plasterer makes no difference - IT`s A LASH UP . and the builder wants a spanking I`d love it : Watchdog on the TV would be the first port of call - and I`d be sitting outside one of the builder`s prestige site sale houses with a big placard and the local news tv crew in attendance Retired and spoiling for a fight

 

[Micilin]

there are 2 problems, 1 is the beads, the other is the blown render which is the one i was talking about.

i don't stop selling houses in the winter either, and we normally get harsher winters where i am than a lot of the uk does. that doesn't mean i get to shrug my shoulders and ignore what time of year it is. if i render in the middle of december then some of it is going to fail. with the lime/opc/sand render we use, the weather over the entire period that the lime is calcifying matters. since sand/opc render is doing something else at a chemical level when it cures it may not matter for as long, i don't know and already said as much, but the bottom line is, if you choose to do things at less than ideal times of year and in less than ideal ways, it's really down to you to sort it out afterwards. 'i have to keep building' is a bs excuse.

Hi -

I was not offering it as an excuse - it would be a poor one - but trying to help the guy make a good case .

It is simply not realistic to say you can't render in 'winter' ie a blanket condition, as there are plenty of weeks when you can. You'll lose credibility if you come out with that. You can say in winter the condiitions are more likely to adversely affect render, but you'd have to show that it was done during a week of frost.

Saying that you can't render in winter would just as likely absolve people from responsibility. You'd have a designated day when winter started and stopped, and out side of that you're given permission to render.

When rendering you have to take so much into account, sun , temperature both hot and cold, wind, rain, frost,background, shelter, which way the wind is blowing, when the sun plays across it, the weather today, tomorrow and rest of the week,. daylight hours available etc . All of this applies every day of the year.It's much worse with your K-rend/monocouche type renders which in winter are applied one day and finished the next - you have to look at cloud cover for overnight conditions and adjust your timings to suit .


So I am saying there is no excuse, winter time or not as each job is done on it's merits (or should be). As a result, you won't get UK builders or NHBC saying that rendering in winter time is poor practice.