how do I render a wall

[purrdy]

Hi
I have a small back yard and want to render one straight dividing wall. It is approximately 15ft long and 7ft high. Currently it just has masonary paint on it.
To be honest I have never tackled anything like this before, but would like to try. How hard can it be? It does not have to have a perfectly smooth finish, just look a lot better than it does at the moment.
What materials will I need and what quantities, also what weather conditions are best for carrying out the work?
I hope someone can advise me
Thanks

 

[DaSpozz]

Ok im not an expert on this one but ill reply since no one else has...

I'd try a sand & cement based render but not sure how this comes, whether it's in 25k bags like plaster does etc...

If so I'd probably say you would need just over a bag for a wall the size of the one you're describing..

Use some PVA on a roller first and give the wall a good coat before you render.

You will probably need a paddle mixer i'd imagine, don't think a paint mixer on the end of a drill will do it somehow.

As for edges not sure whether there is specific beading for this type of thing, but i'd guess so. Ask in Wickes / Trade Depot to see what they say.

Weather conditions - at a guess id go for avoiding extremes.

I'm a plasterer and work on interiors but hope this helped a bit or gave you an idea...

 

[purrdy]

Hi

Thanks for the info, very useful, at least now I have some idea of what is involved. Not sure about the paddle mixer though, I thought it would be like mixing cement - shovelling the sand and cement into a 'well' of water until it is the right consistency.

Thanks again

 

[thompster]

You're right that it's more like mixing cement. Rendering is normally done in two coats using 4:1 sand/cement, 5:1 sand/cement or sand/cement/lime mix - others will argue the various merits of mixes. If you've got a lot to do it might be worth hiring a mixer.

First off you PVA the wall, or as a minimum hose it down well to make sure the moisture isn't sucked out of the render before it goes off.

Mix your mortar up using a waterproofer/plastiser and apply to the wall using a plastering trowel and a plastering hawk. The first coat is called a scratch coat, should be as even as you can get it and about 10mm thick. After applying the scratch coat you scratch it using a special tool or an old screwdriver. This is to give the 2nd coat something to key on to. Corners/edges can be formed using angle bead when you're putting on the scratch coat.

Once the scratch coat has had a few days to cure you can apply the top coat. Most plasterers will initially use a plank/straight edge to level and smooth the surface and then float finish the surface using a wooden float once its started to go off, that can be an hour or so later.

Sand is important. Plastering sand is better than soft sand, or better still get a specialist rendering sand like Leighton Buzzard. Talk to your local builders merchants for advice.

hope that helps.

T.

 

[kingandy2nd]

I rendered my yard walls (about 60ft feet of 6 foot high walls). It's very hard work, but not impossible.

Buy or hire a mixer for the job as it saves time and effort. I used my electric plaster/mortar hand mixer and it was suitable.

Get the walls very wet before you start. My mistake was not understanding how to use my tools properly. I tried to render the yard as you would plaster a house - and it looked terrible!

Only after a second attempt on my 'test' wall did a friend (who is a brickie) tell me that I needed to use a float and go in circles to remove the excess render to level it all out.

After that it was all happy days, and I found that if you were careful with the application of the render you could even do away with the need to use the straight edge and just 'float off' the render to a suitable finish.

Good luck!
ps- there's a render estimator to work out the quantities you need

 

[dlacheson]

One of these replies advises using PVA prior to rendering, I myself wouldn't use it because when PVA becomes heated, it returns to it's origional condition, which would then cause the render to slide down the wall. I don't know this from experience, my plastering tutor at college states this.

 

[weseeyou]

you can buy cement/lime mortar mixes ready mixed in bags quite cheaply.
try a small area for adhesion first and if it isn't adhering then for such a small area of wall you could attach some expanded lath or wire mesh etc to provide a key or rake out the mortar joints

 

[roughcaster]

One of these replies advises using PVA prior to rendering, I myself wouldn't use it because when PVA becomes heated, it returns to it's origional condition, which would then cause the render to slide down the wall. I don't know this from experience, my plastering tutor at college states this.

If ordinary PVA gets damp or wet, it can/will return to it's original wet condition, "not" when it's heated,,,, surely.

Roughcaster.