Rendering an internal wall

[Steve C]

Hi, I am planning to render an internal brick wall approx 10 x 10 foot area. Can anyone advise me on whether I can render this just using one coat of sand and cement and if so what ratio should I use ? I was thinking 4 : 1 or 5 : 1 would this be ok ?
Any advise is much appreciated.

 

[Tom.]

Is it a partition brick wall, or external?

Personally I'd use lime plaster, less likely to get damp problems.

 

[shaggy]

My own preference is to use a sand/cement 5:1 mix as one coat.

 

[Steve C]

Thanks for your replys Tom and Shaggy. In answer to your question Tom the wall I am rendering is the inside face of an external wall.
I will probably go for the 5:1 mix that Shaggy suggested.
Thanks again.

 

[legs-akimbo]

the bricks will no doubt be bone dry so will want dampening down first off.
spread a coat of render at the 5:1 suggested then apply second coat immediately onto the first. The first will have taken up (dried quickly) but the subsequent coat will not dry so fast and you will have time to rule and float it to the best of your ability.

 

[Steve C]

Thanks for your reply Legs-akimbo, I have tackled some small rendering jobs in the past but I was wondering on how the Pro's would tackle a larger job such as rendering an internal wall say 20 feet height x 40 feet length ? I have been on a 5 day plastering course and touched on rendering covering the topics such as scratch coat and top coat. On that particular course the instructor only showed us the rendering procedure on a small wall rendering from the top going left to right and working down towards the floor.
So is it the same procedure for working on walls on a larger scale ?
and is it possible to get a way with just applying one coat of render as the person who wants the job done is not fussed on how it looks just as long as the bricks are covered. I know that sounds like a bodge and if I had my way I would apply a second coat and rule off, but the guy just wants it done cheaply and quickly as it is just an old warehouse where he just wants one wall tidied up. Any advise you might have will be most appreciated.

 

[legs-akimbo]

The main disadvantage of a single coat render is that you will need to really apply it to around 12mm thick and more in places if the wall is not plumb, and if it is a thinner single coat then the problem will be it cureing too quickly which when fully dried will turn it into a thin powdery coating that you can scratch away with your fingernails, simply because the moisture has been rapidly absorbed into the brickwork instead of cureing slowly to a rock hard finish. Another difficulty will be ruling off the render which needs to be done while wet and then floating as it sets. If this all happens too quickly then you will be in a panic and a mess and the job will be a bad un!
If you throw on a first coat followed by a second then it only adds a few minutes to the job that is gained back five fold by the ease at which you can proceed with ruleing and floating and devil floating (A light scratch key) skim cement work the following day or the suction will be severe any later than this.
If it is simply a case of covering the existing then damp it down well and throw on a thickish single coat if that is all he wants, for anything half decent work to the above method and you have half the battle won.