Wavy or straight?

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Olican

Olican

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Someone told me that the scratch you put into base coat (s&c) should be wavy and that nhbc insist on it. I never disagree with someone until I look into it. nothing in my JB Taylor on that, I have always done straight horizontal lines. Any thoughts?
 
Wavy, wavy, wavy!! Wavy or straight?
 
when we three coat render we scratch the first coat straight, then the second coat wavy, so every one can see that it has had three coats , that we are charging for.
 
vertical scratch for me.............bubbles has some pics of the very scratch technique
 
used to be horizontal wavy ( was taught this way ) but now cant be arsed so horizontal straight ,

the reason it's supposed to be wavy (as its mechanical key being applied ) is because a wavy line is longer so more key is applied , just in case some are wondering lol.
 
straight for me, wavey just looks more attractive and takes more time, im on priceworkso time is money, nhbc do not insist on a wavey scratch, up here anyway, cant see it being different down south but mabey im wrong.
 
The NHBC expect all plastering/rendering work to conform with the relevant BS and they say wavy lines.
As for wavy lines taking longer, get a grip, they take so little longer as to be unnoticeable by the end of the working day.
 
Defo wavy.

Two reasons. The first is as the water wants to run down the wall, the water will collect in the bottom of the waves and so creating uniform wetness all over. If you do straight horizontal it will not be bang level so the water will run down the scratch to the lowest point making it wet and the highest point will be dry. No good when you dashing and a pain when you rubbing up with one area wet another dry.

The second is relying on scratching it at the right time of wetness. If you scratch it wet and look at it from a side elevation point of view you will notice the top and bottom of the scratch will sag as opposed to the wire taking out a square section. When the second coat goes on the material goes into the sagged scratched and is locked in, it cannot come out. If you do a scratch horizontal or wavy and when it is stiff the wire takes out the material square and if water gets in between the two coats and freezes then the second coat can simply come out of the scratch and it,s off. On the sagged scratch this cant happen.

Anyone who works for me and does a straight scratch gets a kick up the arse and they are off!
 
I was taught to do it horizontally and an old boy I worked with always said a wavy scratch was a sign of a cowboy :-0 "Too much time on their hands if they're making fancy patterns"

BUT, I can see your point about it holding the water :RpS_thumbup:
 
bubbles65 said:
I was taught to do it horizontally and an old boy I worked with always said a wavy scratch was a sign of a cowboy :-0 "Too much time on their hands if they're making fancy patterns"

BUT, I can see your point about it holding the water :RpS_thumbup:
Click to expand...

Sorry Bubs but the old boy was the cowboy where this is concerned.
 
Hmmm, well we all are up here then cos it's unusual to see a wavy scratch round these parts :RpS_blushing:
 
will need to have a look into this, where you getting this info, i have only ever seen 1 guy do the wavey scratch it was on site years ago, i think most guys up here do it straight
 
Rigsby said:
Defo wavy.

Two reasons. The first is as the water wants to run down the wall, the water will collect in the bottom of the waves and so creating uniform wetness all over. If you do straight horizontal it will not be bang level so the water will run down the scratch to the lowest point making it wet and the highest point will be dry. No good when you dashing and a pain when you rubbing up with one area wet another dry.

sorry but i dont agree,because even in a straight scratch your gonna get high points as well as lowpoints,(you dont scratch using a level) so it contradicts what you are saying , i would rather the water run away on a straight scratch than being trapped in the wavey scratch,been scratching straight for 30years never had any agg with it blowing (touch wood) .
Click to expand...
 
what amazes me is the fact that BS STANDARDS are not really available to most peep's without having to take out a second mortgage to buy any !!
 
Anyone got a link where it says straight scratch is recommended?
I thought it was common knowledge in the trade to do a wavy scratch. :RpS_unsure:
 
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