How to get started with rendering

[toddp]

Hi all,

I want to learn how I can render my brick house but have no idea how to get started. I have been going through most of the render related posts on the last 6 pages or so of posts on this forum... there have been a few good ideas but I think what i need is basic step by step 'for dummies' instructions...

Are there any books I can buy or online resources i can use to work out how to get started?

Thanks in advance.

Todd.

[NSP67]

Hope I'm replying correctly without breaking the rules.

I found this. Hope it helps!
http://www.homesite.com.au/outdoors/...bag-and-render

Nick

[john_unitex]

Hi Todd,

You have two options with rendering brickwork, either sand and cement or acrylix render and texture.

What finish are you looking for? A painted render surface or a textured surface (like a sand finish)?

I'm sure there are a few people here that could answer any information on sand and cement.

Acrylic render covers about 3-5 sqm per bag if you have straight brickwork with flush rake joins. Otherwise you will get 2-4 sqm (using a different render) if you need to build up your raked mortar or have uneven brickwork.

Texture is mixed to your colour choice and trowelled onto the render. Buckets are 15ltr and cover approx 8-10sqm.

Tools required;
Bucket
Mixer
Hawk
Steel Trowel
Plastic Float
Plastic Trowel

Mix render bags with water, adding render to water using the mixer. Use the Hawk to hold your render while you trowel onto the wall (use steel trowel), wait for it to start going off then float of in a circular motion with the plastic float. Do 2 coats - wait at least 24hr between coats, longer if colder weather.

Trowel on texture in a similar way, this time using a plastic trowel to finish.

If you need more info I can send you a brochure, just send me a pm.

I'm sure there are others here with loads of experience that can give more advice and tips.

John

[rod1949]

Do a short course at a local TAFE. It won't make you an expert but it will give you an insite.

[pawnhead]

I'm no expert on cement render, but over the years I've asked, and observed the experts and tackled a few projects that came out fine.

Your mix should be about five parts clean sharp renderers sand, one part cement and one part lime or 'plasta masta'. You can mix it in a barrow using a 'larry' (a hoe with two big holes in the blade). Or on a large board, or a concrete slab, make a volcano from the material and fill the centre with a bucket of water mixed with a teaspoon of dishwashing detergent, or Bycol (as a plasticizer that aerates the mix and makes it more ‘workable’). Turn the dry mix into the volcano, and keep turning, and add more water if necessary to achieve a smooth paste like consistency.

Start on the least noticeable face of your house to gain experience. If you make a total mess of it, you can always scrape it off and hose down the wall before it sets. Wet down the wall with a hose to aid adhesion, but not so wet that there’s visible water on the surface, just enough that it’s damp. Unlike extruded bricks, some dry pressed bricks are very porous and will soak up a lot more water before they are suitably damp. Put some plastic at the base of the wall to catch the droppings for re-use.

Shovel your mix onto a large mud board on trestles, and using a renderers trowel scoop up a hawk full of mud from the board. Starting at the top of the wall from one end, scoop a trowel load at a time from the hawk, and smear it on, roughly a bit more than 10mm thick. The experienced can use a flick of their wrist to throw each trowel load of mud on the wall exactly where they want it. Before grabbing another hawk load, trowel the surface so that it’s roughly flat. Any dropping on the floor can be reworked into your mix. If you’re starting at an external corner, then stick a timber straight edge to the mud at the end of the wall, 10mm proud of the wall in both directions. By jiggling it up and down the adhesion of the wet mud may hold it in place, but renderers sometimes use bits of 8mm steel rod, bent into a ‘C’ shape which they hook into the perps of the brickwork.

Whilst you’re waiting for this section to dry, mix up another batch and keep progressing down the wall. Depending on the climate, allow the first section to set for about 1/2 to an hour (perhaps a bit more). By pressing your fingers in you should feel that it’s stiffened substantially since it was applied.

The next bit is tricky to explain (I can draw a diagram if you want), but using a timber or aluminium straight edge, about 3” X 1” X 2 metres long, starting at the bottom of the wall, hold it perpendicular, and flat against the wall at about a 45 degree angle from vertical. Then using an up and down slicing motion (about a foot each way) in the direction of the straight edge (@ 45 degrees), slowly drag it across the face of the wall, whilst slicing off excess material. As the material builds up on the top of the straight edge, tap it endwise on the floor to release it. When you get to the end, use the straight edge that’s stuck to the wall in the corner, as a visual guide, then hold the straight edge on the opposite 45 diagonal and gently work your way back, keeping an eye out for any wavyness in the wall. You should be aiming for about a 10mm finished thickness, and there will be some noticeable depressions that are left untouched by the straight edge. Just trowel a bit more mud in all the depressions, leaving them proud of the surface, but don’t scrape them back yet (they’ll be too wet). Then jump on a stool and repeat for the top half of the wall. Use a square mouthed shovel to carefully scrape the waste away from the bottom of the wall. It can be re-used further down the wall, but you may need to ‘knock it up’ with a bit more water (you’re not supposed to strength wise, but everyone does it without any probs).

After about another 1/2 > 1 hour, scrape of the excess daubs that you applied earlier, then using a paint brush, or a wet sponge, or ideally a renderers brush, flick some water onto the wall (not too much) and using a renderers sponge, float the wall using a continuous circular motion, flicking water on as required to ‘liven up’ the surface. If there are any pock marks or depressions, put a small lump of render on the sponge and press it into the depression before resuming a circular motion. Clean excess render off the sponge periodically. It’s important to only apply a very light pressure, and don’t overwork the wall or you’ll end up with a very irregular scratchy surface without the regular ‘sandy’ look that you’d want to achieve.

Remove the straight edge from the corner by sliding it upwards to break the bond first, then use a corner tool to round the corner off. Use your trowel to cut the excess from the return, about 10mm back from the corner, in a straight line, on a splay (not perpendicular to the wall).

Ideally you should attempt to complete an entire wall at a time to avoid a ‘cold joint’ which can sometimes be noticeable if in the middle of a wall.

Crack a beer and stand back, then you have one of two options. Either admire your work with a smug grin on your face, or start freaking out as you go for your shovel and hose before it sets, then open the yellow pages under ‘R’ for renderers.

[toddp]

Thanks for the replies - the information has been very useful so far. That link also gave me other ideas on google keywords.

I'm still at the stage where i dont understand the difference between "A painted render surface or a textured surface"


One of the things that I have not seen covered at all is how to handle windows/doors/sills etc.

The other thing I worry about is removing downpipes, my hot water cylinder etc.

Until recently I used to pay everyone to do things like this, but recently have been doing more and more handyman type jobs (at the moment, I'm nearly finished building an internal wall/doorway) - i'm really enjoying the challenge.

I did not think about TAFE at all. I will look that up now, perhaps that would be the best path forward.

Thanks,
Todd.

[Gra]

could always talk with the CIA

[john_unitex]

>I'm still at the stage where i dont understand the difference between "A painted render surface or a textured surface"


Painted surface: Paint over the render

Textured surface: Granulated marble (colour added)

[toddp]

Crack a beer and stand back, then you have one of two options. Either admire your work with a smug grin on your face, or start freaking out as you go for your shovel and hose before it sets, then open the yellow pages under ‘R’ for renderers.

Hahaha, i nearly fell off my chair. This is very very good info.

I had thought of starting at a back wall, it also has no windows etc and is relatively short compared to other walls.

I believe I understand what you mean by the straight edge @ 45 degrees

Good point also about the cold joint, It would be like me to only try a couple of metres wide to see how i go... I will make sure that I do the full wall.

Thanks again. There is a lot of great info on here.


Also John: I think i already downloaded the brochure from Unitex in my research a couple of days ago, had seen you post a fair bit on the topic and so followed it up from this board

Cheers
Todd.

[pawnhead]

One of the things that I have not seen covered at all is how to handle windows/doors/sills etc.

Basically the same as an external corner. You need a straight edge the length of your sill. apply a 10mm mortar bed on top of your sill, then push your straight edge onto it, leaving it hang 10mm out, then use it as a guide when you apply render to the face. When the face has been sponged off, carefully apply render to the top of the sill trying not to damage the corner.

A much easier way to do all of your external corners, including around all of your sills, is to fix render beads to all your corners first. Use a straight edge to ensure they're straight when you fix them. You could probably nail them into the brickwork joits with clouts, but if it's too hard you can drill and spaghetti before nailing. This way you don't need to worry about straightedges and corner tools. They come in different radius's, and they're unnoticeable when painted.

If you're return rendering into a window or a door jamb, you should use your trowel to cut a small vee against the jamb. Otherwise through expansion movement/slamming of doors, you may get some cracking. The vee can be covered by a small storm mould bead.

I'm still at the stage where i dont understand the difference between "A painted render surface or a textured surface

It's a matter of taste, but personally I'd prefer a painted smooth rendered look. It looks more like a traditional solid brick wall, than a cheap blueboard wall.
I've got no experience with it, but texture coat may be easier for a handyman to apply. I'd say that it would also hide imperfections a bit better as well.

[Fuzzie]

Just a point on 'render beads'. For external work you can get nylon beads (from I don't know where, maybe try Rockcote). I recommend if you are going to use beads get the nylon ones. Our house was rendered using metal beads that started rusting in no time. After several years of cringing looking at the rusting house facade we found a REAL plasterer who charged only a small arm and leg to cut out the rust and redo it without the assistance of beads.

[john_unitex]

> Just a point on 'render beads'.

I would recommend only using stainless steel external angles (grade 304). These angles won't rust, they are the same grade of steel as your kitchen sink.