Silly brickwork question.......

[JDLDIY]

Hmmm...don't think I've seen Top Secret either, just finished watching Van Helsing though - right up my street that.

When I say small jobs I mean really small. The job to start with tomorrow only involves 3 bricks for example. So, a ratio of 1:16, plasticiser:water works above -4C and double that for lower temperatures?

 

[JDLDIY]

Hmm.......I don't get these proportions I'm supposed to be using.

The normal plasticiser says 0.25 to 0.5 litres per 100Kg cement or 0.5 to 1 litre per 40 litres guaging water.

The Feb wintamix says 5 litres per 100 Kg cement, so 10 times the ratio of the normal plasticiser above, which I make 10 litres to 40 litres of water 1:4 whereas

About a half pint per gallon should be about right. In extreme cold (Lower than 4 below Zero Centigrade) you should increase the dosage, to a pint per gallon. You should also increase the dose if your sand is excessively wet. (as you won't be adding so much water).

Tex, you are saying a ratio of 1:16?

Looks like the temp here won't drop to freezing at the mo' but I'm keeping an eye on it..........

 

[JDLDIY]

After much foraging on the net, just found thishttp://www.degussa-cc.co.uk/Buildin...s/BuildingSystems/DataSheets/Wintamix TDS.pdf
Which seems to suggest that a ratio of 1:14 might be right?

 

[TexMex]

After much foraging on the net, just found thishttp://www.degussa-cc.co.uk/Bui...s/BuildingSystems/DataSheets/Wintamix TDS.pdf
Which seems to suggest that a ratio of 1:14 might be right?

Looking at page 2 of the datasheet that you have found, it specifies.

Dosage
Ambient Temperature down to –4 Deg. C.
5 litres per 100 Kg cement.
Ambient Temperature below –4 Deg. C.
10 litres per 100 Kg cement or 7:1 with water.

7:1 with water would be 1 pint per gallon. Halve that (for ambients above -4) comes out to half a pint per gallon. Actually, the doseage should be related to the cement content. Due to the variable moisture content of the sand, the amount of water that you add to a mix can vary quite a bit. Therefore a specific ratio of admix to cement, cannot be directly translated into a dosage in the water.

Fortunately you have plenty of latitude on this one. Assuming we're not going to experience sub -4 conditions, Anything between 1:16 and 1:8 would be fine (and you probably even have a good deal of lattitude each way of that). The more you use, the faster the set time. For small jobs this isn't going to be a factor.

BTW. It's quite normal for frostproofer to be added at a higher rate than normal plasticiser.

 

[JDLDIY]

BTW. It's quite normal for frostproofer to be added at a higher rate than normal plasticiser

Ahh.. I see. Thanks for your reply Tex. Well, I had a go at the main outside hole yesterday and what a disaster! I ran out of mortar and daylight, but not before I could see what an awful job I had done of it. As with so many skills the time to practice is not when you need to get the job done. For one thing whilst the mortar was a great malleable consistency on the spot board as soon as it got anywhere near the bricks it became crumbly - any thoughts? I was thinking that the moisture was being drawn out into the bricks so I made sure I dampened down first but that seemed to make little difference.
I am hooked on the whole bricklaying thing though and have been looking for a part time course to do. Not easy being a shift worker though. Any advice on the whole trowelling technique would be good - especially to see how to get the right amount onto the trowel, get it off the board etc and then to lay it. Mind you for the job I'm doing here the normal technique is pretty useless as a brick trowel is often too big for the space.

Thanks again.

JD