Hessian fabric known as Burlap or Jute is a woven fabric made from the skin of the Jute plant.
Hessian is used in the construction industry to protect brickwork from cold weather, frost, direct sunlight and humidity. It is used in curing of newly poured concrete which prevents water damage by holding it.
Mortar in brickwork can dry out too quickly, reducing hydration and carbonation, leading to shrinkage of the mortar. On the other hand if the mortar dries too slowly water will be held in the mix, making it frost feeble and sensitive to lime migration. There is also a danger that mortar may freeze before drying.
The solution is to use a Hessian screen to protect the brickwork from direct sunlight, and to reduce the effects of wind. Water dampened Hessian wrapped around the brickwork will protect it from heat and prevent it drying out too quickly.
Hessian fabric protecting brickwork on a building site. The Hessian is held in place either by bricks or large plastic clips.
Bituminised Hessian is constructed from Bitumin, a tar like substance manufactured from petroleum residue, which is coated on paper and then Hessian. The Bitumin and paper combined with Hessian create a waterproof layer which is also resistant to temperature fluctuations, making this ideal for protecting outdoor brickwork and concrete.
Hessian will also stop the mortar from becoming over saturated by rainfall, the cloth acts as a sponge, soaking up much of the moisture and protecting against the worst of frost and cold.
