How much hair do you use in your lime plaster?

[Anonymous]

How much hair do you use in your lime plaster?

I am about to make up a batch of course lime plaster for the first coat against masonry.
I have read on this site that 4kg of hair will do 1 cubic metre.
So do you agree that a 1kg bundle will do 250 litres of lime plaster?

Also, I also have to knock up some limecrete for some larger areas, (lime, sand and aggregate). I have read differing proportions on the net, any experience appreciated.

Many Thanks

Bry

 

[Anonymous]

Bry
I see you are plastering to masonary. I vaguely remember a Bob Bennet discussion on this a couple of years ago , where he went on to say that as you are plastering to masonary suction was the main force holding it all together. You will not need as much as you would with lathe and plastering.
May I also suggest the hair used also makes a difference depending on it's protein makeup.

A good site for info http://www.buildingconservation.com/articles/limehair/limehair.htm

Also as for mixes , I got away with a 1:2.5 with no hair on masonary , and its holding just fine , 6 floors high and getting a battering from the harsh unforgiving fens.

 

[Anonymous]

I get my hair in bundles as thick as a teenager's wrist, and chop off two-inch chunks. One two-inch chunk - weighing around four ounces - teased out, does one cwt (112lb) of plaster - about 50 litres by volume.
If you dig your trowel into the plaster and lift some out, you should be looking for a 'fringe' around the edge with around 20 hairs to the inch.

 

[Anonymous]

Thanks for the replies.
I’ve got my hair from Ty-Mawr Lime.
The reason I was asking about ratios for more of a limecrete than a plaster, is that I have some large holes to outside, where in the past it has been filled with cement.
I was going to replace the larger with bricks and mortar, but in some, I was going to use a limecrete before I plaster.
I read somewhere that when you mix up a limecrete, you discount in the calculation the volume of aggregate larger than a couple millimetres.

Bry

 

[Anonymous]

Thank for the replies.
So you just cut 2 inch off the end as you need it, not full length.
I have not used hair up to now as all the other plastering has been just thin top coats.
The lime has been sitting for a few months now, and a small cement mixer is being picked up at the weekend, so my summer is spoken for.

Bry

 

[Anonymous]

How do you mix in the hair. I do it by hand with the mortar spread on the mixing board and fold it in. I still find it a sod to stop it clumping up though.

 

[Anonymous]

I'm afraid I cheat and use a cement mixer, and stand facing the bel with a large chunk of hair, teasing it in bit by bit. It is a tedious job, but better to have it distributed evenly through the plaster than have loads of 'dead mice' to deal with.