Properties and Benefits:
Hessian, sometimes referred to as Burlap, is a loose woven natural fabric made from fibres of the jute plant, it’s use is widespread in several industries. A very robust material that can withstand repeated wetting and drying without compromising its strength, and as such very common in the construction industry for the curing of concrete especially. In the context of lime mortars and renders, Hessian is (or certainly should be) your primary material of choice for their aftercare; a very useful frost blanket during the colder months and when wetted down during the warmer months it can serve as a very useful humidity cover, preventing mortars from rapid drying out; one of the most common causes of failure in lime mortars, it also acts as a useful wind break reducing the action of wind drying; all very important for the appropriate curing of lime mortars and renders.
Hessians are categorised by their weight, expressed as “gsm” or grammes Per Square Metre with the lower number representing a more open weave to the fabric with less material used, hence it being lighter. Cornish Lime stock 3 grades 229. 273 & 366 gsm - grammes Per Square Metre. Available in full rolls measuring 50 x 1.8 Metres (151 x 6 feet) or by the metre cut from the roll, which will be slightly more expensive for obvious reasons.
For further information on the aftercare of lime please see our document “Curing Mortars and Renders”