Rendering query

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Discussion

sparkythecat

Original Poster:

8,015 posts

270 months

Sunday 7th June 2009
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My house was built in the '60s from concrete common brick. For years it was painted white, then someone applied some sort of textured white polymer coating over the paint. As time went on the coating began to flake off , so subsequent occupiers painted over it again. Eventually tired of re-painting another occupier had the house pebble-dashed. And then someone painted over that!

When I moved in it looked OK, but there were hidden problems. Because of the layers of paint and polymer underneath, the pebble-dashing wasn't properly keyed to the brickwork. Seven years of weathering and it's now falling off in big patches, bringing with it some or all of the paint and polymer coats.

My own feeling is that if all the pebble dash is knocked of, I should get it sandblasted back to bare brick, to provide a key for the new render. I realise that this is an expensive option. A plasterer who has come to look at the job has suggested keying the brickwork with an angle grinder, as an alternative to sand blasting. He's talking about digging out some of the mortar joints in the brickwork and diagonally cross hatching the brickwork.

Would appreciate the views of any plasterers/builders on here

saleen836

11,926 posts

224 months

Monday 8th June 2009
quotequote all
Alot easier to use a 'scabbler' this will take off loose paint etc and give a key for new render.

GreenDog

2,261 posts

207 months

Monday 8th June 2009
quotequote all
saleen836 said:
Alot easier to use a 'scabbler' this will take off loose paint etc and give a key for new render.
What's a scabbler ?

FlossyThePig

4,133 posts

258 months

Monday 8th June 2009
quotequote all
GreenDog said:
saleen836 said:
Alot easier to use a 'scabbler' this will take off loose paint etc and give a key for new render.
What's a scabbler ?
Google returned 7,310 English pages for me.

GreenDog

2,261 posts

207 months

Monday 8th June 2009
quotequote all
FlossyThePig said:
GreenDog said:
saleen836 said:
Alot easier to use a 'scabbler' this will take off loose paint etc and give a key for new render.
What's a scabbler ?
Google returned 7,310 English pages for me.
And you couldn't have posted a link to one of them ? Lazy bugger ! wink

saleen836

11,926 posts

224 months

Monday 8th June 2009
quotequote all
GreenDog said:
FlossyThePig said:
GreenDog said:
saleen836 said:
Alot easier to use a 'scabbler' this will take off loose paint etc and give a key for new render.
What's a scabbler ?
Google returned 7,310 English pages for me.
And you couldn't have posted a link to one of them ? Lazy bugger ! wink
Appologies, here you go...
http://www.refina.co.uk/powerprep.php?gclid=CPH0iv...

sparkythecat

Original Poster:

8,015 posts

270 months

Monday 8th June 2009
quotequote all
saleen836 said:
Alot easier to use a 'scabbler' this will take off loose paint etc and give a key for new render.
Thanks for that, I'd never heard of a scrabbler before.
What are they like to use, in terms of noise, dust and vibration?

saleen836

11,926 posts

224 months

Monday 8th June 2009
quotequote all
sparkythecat said:
saleen836 said:
Alot easier to use a 'scabbler' this will take off loose paint etc and give a key for new render.
Thanks for that, I'd never heard of a scrabbler before.
What are they like to use, in terms of noise, dust and vibration?
Vibration reducing handles and most can be hooked up to an extraction unit.

V12Les

3,985 posts

211 months

Monday 8th June 2009
quotequote all
Its not the weather thats making the pebble dash come away. Common bricks shouldn't be rendered. If you can afford it, look into the likes of "K Render".

Road2Ruin

5,933 posts

231 months

Tuesday 9th June 2009
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Sandblasting! Who on earth recommended that? If it is rebdred concrete block then the best thing to do is get the largets bolster chisel you can and hack it off with a hammer. You will be amazed how easily it comes off. While its off consider having your cavity walls insulated (save mess for future) the unibond the walls and re-render. When rendered give it a loose coat of masonary paint followed by two good coats of a quality masonary paint.

sparkythecat

Original Poster:

8,015 posts

270 months

Tuesday 9th June 2009
quotequote all
The existing pebbledashing comes off fairly easily, but what's left underneath are the patchy undercoats of paint, and polymer coating. It is these coatings the sandblasting was intended to clean off the brick, so the new render would stick. A bolster isn't really the right tool with which to clean paint off a wall.


Cavity wall insulation is a good idea, but it's already been done.

robinhood21

30,929 posts

247 months

Tuesday 9th June 2009
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Might be worth looking at a needle gun as well as the scrabbler. Either way, a lot of hard work. Another option would be to fix galvanized wire mesh to the walls, then re-render.