Pebbledashing? Is this right.

[ShaznMark]

Well guys we are finished our bit of blocklaying successfully and its all solid as a brick wall . Having rang around quite a bit we are having difficulty getting someone to come and pebbledash it now to match the rest of the house. Why not have a go ourselves?
After a little bit of research we have come up with the following.

1. Dust down and paint with PVA mixture.
2. Plaster on sand and cement mix and 'scratch' it.
3. Leave for a few days.
4. Plaster on final sand cement mix(wetter).
5. Mix up pebbles with sand and cement and 'fire' onto wall with bucket trowel.
6. Install the window and plaster the reveals.

Are we doing this in the right order?Should we put the window in first then plaster the reveals, then do the rest?Dying to have it finished for Christmas!!

Thanks for any help!
Shaz

 

[masona]

5. Mix up pebbles with sand and cement and 'fire' onto wall with bucket trowel.

Not heard of this one, normally the stones are 100% clean with water then flipped up 45 degree angle onto the wall.

 

[legs-akimbo]

What Masona describes is a dry dash, Shaz n Mark what you describe is a wet dash or Harling...or actually a combination of both, can you clarify what finish you are hoping to achieve???

 

[ShaznMark]

Hey guys thanks for replying, the pebbledashing on the rest of the house looks like it was mixed up with the sand and cement. Wet dashing then?
shaz

 

[ShaznMark]

Legs Akimbo have you had a heart attack! Going to give it a shot at the weekend with mark any last tips would be nice!
luv shaz

 

[Thermo]

heres one, stick plenty of dust sheets or boards down by the walls to collect all the stuff that comes back off the walls, it can make a mess!

 

[ShaznMark]

Thanks Thermo, plastering is the messiest of all trades I'm just glad the hubbie isnt one!!
Was talking to a guy yesterday about doing it for us I wont tell you the quote but lets just say it was clear he didnt want the job!
Just on a side note one thing I am afraid of(and I'm not of many) is plastering the top reveal. Am I right in that its like plastering a ceiling you just spread it on? Is there a trick like using beading or something?
Thanks again
shaz

 

[masona]

To be honest, it's not easy, I have a friend in peddledash trade and that all he does, not even plastering!! I would try and get a few more quote first. Can you tell me what the price was and how many square metre the area of the wall?

 

[legs-akimbo]

Hi Shaznmark...sorry for the delay I should indeed have had a heart seizure this week as I have been doing some late nights, so no time for the forum.
Rough casting: a 3:1 sand cement mix or not a weaker mix than 2:1:9 cement lime sand, if using lime, use a well graded, clean plastering sand.
Permutations for harling are infinite so you will have to gauge how much stone and the size of from the original...do not be sparing with the pebble.
Do not under any circumstances add a waterproofer to the scratch coat, Harling is a thick coat and you NEED suction on the scratch so that it will not slide as water drains down the back of the harling as it is applied. The mix needs to be fairly sloppy and applied with a paddle. Throw with some decent force and let it slide from the paddle rather than directly at the wall. Throw alternate right angles and do not try to touch up with a trowell as this will make the problem area more obvious ....dip a bristle brush into the mix and bang against a timber held in front of any dry patches to fill them.
Be aware it is not easy so good luck

 

[ShaznMark]

Poor Legs Akimbo! What addiction has you doing late nights!
Great advice guys, thanks. So this is what we are now doing.
1.Dust and PVA the blockwork, leave for a day.
2.Prepare the area to be plastered, using external angle beading on the reveals.
2.Apply a 3:1 sand cement mix to the reveals(which will be the finish), and to the blockwork(as a scratchcoat).
3.Leave for a day or two?
4.Apply sand cement mix at 3:1, then immediately mix up pebbles, sand and cement in a wet mix of the same, and 'throw' at the wall.

2 questions, I promise the last ones! How long to leave after the scratchcoat? Should the second coat be quite thin in order to still get the suction from the final dashing coat(which is applied asap after the second coat)?
I just cant wait to have it finished!!

shaz

ps any tips on that top reveal!!

 

[diy_man]

Hi Shaznmark
I have been watching your post with interest as I will be helping my mate try to get a similar finish when he has finished his garden wall.
You will need to leave it for one day after the undercoat, but if it rains on it leave for longer! The undercoat should be about 10-15 mm thick, and levelled off properly as you will need to remove the battens you have used to gauge the thickness after this coat, and when you go to put the final coat on it should be only a few mm so wont make a difference to the level.
I am keen to find out exactly how to do the reveals and get that nice 'lip' on them, when I did this before a year ago I made a dogs dinner out of it. I used 50mmx25mm battens around it with another batten nailed to that making a sort of a box, except when it came to getting the render to stay in the box it failed miserably!
I dont think you need to use external beading, I didnt and it stuck to the corners easy enough.

will

 

[ShaznMark]

Hi everyone thanks agaoin for all the sound advice, we put on the undercoat and left it a few days, then today we were mixing up the dashing and stopped..its too grey!The rest of the house is unpainted i'm pretty sure, and we need to match the colour which is yellow/white. Did we use too much cement in the mix or are we supposed to be using white or coloured cement?
cheers boys
shaz

 

[bryden]

yes a yellow/white looking finnish depending on the weathing effects is white cement with norml building sand.
from experence b and q or wicks sand is not the beast match see if you have a depo of these guys near (www.rowebb.com) or a general building merchants near as they have building sand which is a little more yellower than red(sorry im a perfectionist at heart )
also use a mixer and get a little freeflow or a little lime makes the mix like cream which is a breezze to spread on.
a well mixed mix with a good bit off freeflow is not a prob on the soffit(bit above the window)
hope this helps.
cheers b.