Hair or fibres in limeplaster

[herb]

Which is the best hair or fibre to use in lime plaster? Is there an ideal length, or is it different for the various coats?
Is Polypropylene fibre any good for stopping cracking? I am just concerned that natural hair may degrade if the wall becomes damp again.

 

[malc]

we use goats hair [as we have a lot in stock] for lime mortar. fibre would be ok if it is long enough, the fibre that i have seen recently have been very short therefore i thought it was useless.
i have never seen natural hair break down.

 

[superspread]

Like Malc said goats hair all day long

 

[puddove]

Like Malc said goats hair all day long

Billy or nanny ?:RpS_laugh:

 

[bodders13]

Hey you can use either of the 2. The hair itself doesn't break down from moisture it gets eaten by the alkaline. Once the Lime has cured this is perfectly fine and has been used traditionally for 100's of years. If you are concerned about the hair then you can use fibres. It is not the length of the fibres that affect the strength, more the quantity. You can stick hair in the mix but if there isn't enough it wont make a difference. I normally used polypropylene fibres unless its listed and needs the real deal. 12-19mm length fibres are quite acceptable to use. You can get longer but are a nightmare track down. Recommended quantity is 1.5kg per Ton of lime Mortar for Lime which is the same for hair or fibre. As the fibres are shorter and weigh less you get alot more. YOu can also use a fibred mixed for both backing anf top coat where as hair coats should only be the backing coat and not your float coat unless you want a skimmed wall full of pubes. If you have alot to do then it might be cheaper to buy it Pre-mixed. Where abouts are you from? How much Lime do you think you need or the square meterage to cover?