External render question

[Simon]

Hi there,

I'm plnning to render an external wall. It's concrete block construction in the main, with 2 courses of brick just under DPC, then more concrete blocks.

When I render the wall, is it best to stop just before the DPC with a drip bead, then continue render below the DPC - thereby avoiding breaching the DPC?

Also I'm planning to complete this work over a number of 2 hour slots in the evening - how best to split this up - I was thinking dividing the wall into "strips" and doing one a night, keeping it wet as it's quite warm outside at the moment.

Also, what's a good mix for this type of coating and to what depth should I go. Also also just one render or do I build it up in tow layers?

Any advice appreciated!

Thanks.

Simon

[Simon]

Advice anyone? :-)

[Cicero]

=============================== Render is usually applied in two coats. The first is a thin coat and is scratched or scored with a trowel or a nail comb whilst it's still soft to produce a key for the second coat. This first coat is called a 'scratch coat' for obvious reasons.

The second coat is applied when the first coat has hardened - a day at least later. Most people apply this second coat in strips or bays as you suggest but others prefer to do it in broken areas to avoid seeing a draughtboard effect in the finished job. This finish coat(about 3/4" + thick) can be trowelled smooth or wiped with a wet sponge in a circular pattern.

It's not normal practice to render below the damp-proof course. Finish with a drip strip about an inch above the DPC and leave the course below clean.

People argue about the best mix(es) but something about 4:1 soft sand / cement is about average. It's worth asking where you buy your sand for 'rendering sand' as they will almost certainly be familiar with what tradesmen are using locally for the job.

Cic.

[The Natural Philosopher]

I think sharp sand looks nicer..

[Cicero]

---------------------------

---------------------------------- Which confirms my point quite nicely.

The best mix is the one that you want unless you allow yourself to be persuaded by other people. I suppose the subject was being debated quite warmly when the first wattle and daubers started to offer their services.

Cic.