Rendering a single storey extension advice please

[drpplastering]

Hi guys!! Not been on for ages

Just wanted a bit of advice/clarification please

Near enough all of my work is internal and I've not had much hands on external rendering s & c or krend etc other than the odd patch up.

I'm really keen to get hands on and I've got a single storey bathroom extension to practise on, it's mine so it doesn't matter!

this is how I'm thinking of doing it, please feel free to pick me up on mistakes, I'm after advice at the end of the day.

hack off old render and set beads in level

The bricks are common bricks, in decent condition, I wasn't going the rake out the joints for a key

damp down a little, 4:1 s & c scratch coat with waterproofer in it.

give it a day at least to dry and go on it with a 5:1 top coat with plasticiser in. Plain face render finish with poly float then sponge.

like I said the bricks seem half decent, would I need a bonding agent or slurry coat or just damp down?

long winded i know!! Just wanted to get it spot on

cheers
dan

 

[johniosaif]

Leave a week between coats,I would just damp down,but you can scud for extra key, 4/1 scratch with water proofer, float coat 6/1/1 sand cement lime,
ps you could try ocr and make it one day job after setting beads etc

 

[Olican]

So many different ways to approach this, agree with John his method.

 

[keithuk]

Mono it mate :RpS_thumbup:

 

[Dr.B]

I would stipple/scud the bricks with SBR/cement slurry especially if they are lbc common type bricks.

 

[drpplastering]

Thanks,

john, lime in the top coat as a plasticiser or for breathability?

Ive heard of OCR but don't know much about it, what's the cost of a bag? do you use the same gear for base coat as top coat?
Thanks!!

 

[Ashmilson]

I never knew to wait a week between coats. Must take the advice as my wall at home has hairline cracks. I've bin told to mix 2 building 2 sharp 1 cement for the first coat and then 3 building 1 sharp 1 cement with waterproofed in the 1st mix and plastercizier in the 2nd. Any other things to mention? Cheers guys

 

[johniosaif]

OCR is one coat render, so two passes of the same gear not used it. Yet myself but will very soon,lime for plasticiser and flexibility ,

 

[drpplastering]

Thanks john

 

[smoother09]

Weber it job done..

 

[drpplastering]

John, Sorry just another couple of other questions!!
Can you recommend a good waterproofer plasticiser?? Is feb any good? Also I presume it's hydrated lime in the top coat, roughly how much lime for a mix? would there be any point with plasticiser in topcoat if I'm adding lime?
also is there any basic ways of working out materials, sand & cement etc? I can walk into a house and know how much plaster I'll need but not got much idea with the s & c materials, don't want to get far too much or too little!!
a few questions (sorry!!!)
thanks again!!

 

[johniosaif]

Water proof plasticiser is an oxymoron ,as in one cancels the odd out,like wet/dry.. Feb prof should be fine though, for top coat 6/1/1 sand cement lime .no need for extra plastisizer in my opinion, @rigby

 

[Dr.B]

I like cementone freeflo waterproofer or jewsons own brand one myself, you get a lovely creamy mix with em.